Received: 2 July 2021 Revised: 15 July 2021 Accepted: 16 July 2021
DOI: 10.1002/fft2.106
H I GH L I GH T S
A profound explanation of why eating green (wild) edible plants
promote health and longevity
Mauri Kalervo Åhlberg1,2
1 The Faculty of Educational Sciences,
University of Helsinki, Helsinki, Finland
2 Professor Emeritus, Klaneettitie 12 C 36,
Helsinki 42, Finland
Correspondence
Dr.MauriKalervoÅhlbergProfessorEmeritus,
TheFacultyofEducational Sciences,University
ofHelsinki,Helsinki, Finland.
Email:mauriahlberg@gmail.com,
mauri.ahlberg@helsinki.fi
Abstract
From1970, research evidence has accumulated that theMediterranean diet promotes
health and longevity. Its main components include local (wild) green vegetables, citrus
fruits, and olive oil (extra virgin). Since the 1990s, experimental research on phytochem-
icals to explain why plant food is healthy and promotes longevity has grown exponen-
tially. Nowadays, molecular biology provides deep explanations for many experimen-
tally found health-promoting properties of plant species and their phytochemicals. The
specialized approach is OK because it is the way research progresses. Mainly, nutri-
tional researchers concentrate on a particular group of compounds such as flavonoids,
phenolic compounds, carboxylic acids, fatty acids, and so forth. Science outside the
research on nutrition deals with the same chemical compounds but which nutritional
researchers generally do not follow. Plant biologists have found that all photosyn-
thesizing plants share many compounds and ions. They are vital to plants. Some of
the compounds and ions are also vital to humans. Plant biologists make a distinction
between minerals, primary metabolites, and secondary metabolites. This distinction
applies partly to humans. Plant minerals and primary metabolites often are essential
to humans. Plant secondary metabolites are often not vital to humans but experimen-
tal research has shown that they promote health and longevity. Eating local wild edi-
ble plants (WEP) also promotes sustainability. WEPs are an ecosystem service. I have
found 52 compounds and ions that all green edible plants share, promoting human
health, well-being, and longevity, and I present the evidence in this paper.
KEYWORDS
food-and-nutrition, green edible plants, health, sustainable diets, the Mediterranean diet, wild
edible plants (WEPs)
1 INTRODUCTION
According to Jacob & Albuquerque (2021), interest inwild and culti-
vated food plants grows. This theme integrates the frontiers of knowl-
edgeof various areas, such as nutrition, plant biology, public health, and
humanities.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided
the original work is properly cited.
© 2021 The Authors. Food Frontiers published by JohnWiley & Sons Australia, Ltd and Nanchang University, Northwest University, Jiangsu University, Zhejiang Univer-
sity, Fujian Agriculture and Forestry University
Cannataro et al. (2021) state, “Angel Keys, a biologist and phys-
iologist who based his conclusions on his studies focusing on the
dietary habits of people living in Southern Italy, was the first to present
the phrase ‘Mediterranean diet’ to the popular imagination, invest-
ing it with a scientific and cultural meaning.” I agree with all other
points in this claim, but the first name of Dr. Keys is Ancel, not Angel,
240 wileyonlinelibrary.com/journal/fft2 Food Frontiers. 2021;2:240–267.
ÅHLBERG 241
according to Keys (1980), Keys and Keys (1975), Montani (2021), and
the Seven countries’ website. This official website integrates the his-
tory and achievements of the Seven countries study between1947 and
2020, https://www.sevencountriesstudy.com/about-the-study/.
“The Mediterranean diet varies by country and region, so it has
a range of definitions” (Cannataro et al., 2021). According to Lassale
et al. (2019), Marrelli et al. (2020), and Dinu et al. (2018), the Mediter-
ranean diet is one of the best-studied dietary patterns used in the
countries surrounding the Mediterranean. Salehi et al. (2020) present
an overview of how the Mediterranean diet and its wild edible plant
diet protect the quality of life, healthy aging, and longevity. Accord-
ing to Gehlich et al. (2020), frequent consumption of fruits and veg-
etables correlates with improved health outcomes, including physical,
cognitive, and mental health. This association results from many lon-
gitudinal epidemiological research programs found at least from the
1980s. Because minerals and antioxidants did not explain the health-
promoting effects of fruit and vegetable consumption, researchers
have searched and found other health-promoting compounds and phy-
tochemicals of edible plants.
Cannataro et al. (2021), García-Montero et al. (2021), and Åhlberg
(2020) state that the originalMediterranean diet includes local vegeta-
bles (both wild and cultivated), onions, wild edible plants (WEP), citrus
fruits, pomegranates, berries (if available), legumes, walnuts, oregano,
other spices, whole-grain foods, fish, other seafood, monounsaturated
fats of olive oil, and polyunsaturated fats ofWEP.
According to Cannataro et al. (2021), “The Mediterranean diet rep-
resents one of the first examples of a positive correlation between diet
and cardiovascular health.” García-Montero et al. (2021) maintain that
the Mediterranean diet is a model of healthy eating to prevent non-
communicable diseases, including obesity, type 2 diabetes, cardiovas-
cular diseases, and some types of cancer. Furthermore, they state that
diet is the greatest immune systemmodulator. Therefore, theMediter-
ranean diet promotes a healthier immune system.
According to Cannataro et al. (2021), “We chose six polyphenols—
(1) Naringenin, (2) Apigenin, (3) Kaempferol, (4) Hesperidin, (5) Ellagic
Acid and (6) Oleuropein—present in Mediterranean food.” Åhlberg
(2020) states that these compounds are also in severalWEPwith glob-
ally extensive distributions reaching outside theMediterranean area.
From the following research articles, I have found information about
what is common to all plants: Hasanuzzaman et al. (2020), Huang et al.
(2020), Šamec et al. (2021, p. 826), Marchiosi et al. (2020), Kumar
and Goel (2019), Andresen et al. (2018), and Harborne (2000). When I
found other chemical constituents of plants that I guessed based onmy
biology studies at the university, whether all edible plants share them, I
tried as keywords<the name of phytochemical>,<plantmetabolism>,
and <plant biology>. I integrated and developed ideas deeper and
broader using Google Scholar, PubMed, Europe PMC, SpringerLink,
and ScienceDirect. I found research evidence that every green edi-
ble plant contains 52 health-promoting constituents (compounds and
ions).
According to Šamec et al. (2021), for example, all plants use polyphe-
nols in abiotic stress response. There are over 8000 different polyphe-
nols. They share common properties, which I describe in detail. Šamec
et al. (2021) state that the structure of polyphenols varies extensively.
However, their common feature is the presence of more than one
hydroxyl substituent, attacheddirectly to oneormore aromatic or ben-
zene rings. Polyphenolic compounds are molecules with similar bio-
logical activity, and especially in biological studies, researchers mea-
sure total polyphenol content as amarker of biological activity.
1.1 Levels of explanations on why green plants
(vegetables) are healthy
1.1.1 The level of minerals and vitamins
According to Nashawaty et al. (2021), epidemics of nutritional defi-
ciency disorders caused by a lack of vitamins and minerals were still
common in the 19th century in Western countries and claimed many
victims. Fortunately, advances in nutrition have led to improved diets
and a decline in the incidence of these disorders. Scientific knowledge
of minerals in nutrition comes partly from the 19th century of vita-
mins and the 20th century. According to Trüeb (2020) and Mozaffar-
ian et al. (2018), researchers identified all vitamins between 1913 and
1948.
Curtis and Whelan (2019) have written a book about the wild food
plants of Ireland. Unfortunately, there are few minerals (four men-
tions), vitamins (14 remarks), and nothing of phytochemicals.
Nyerges (2019)wrote a book onCalifornianWEP. There are only 15
mentions of vitamins, mainly A and C, and nothing about minerals of
WEP. There is nothing about phytochemicals.
FollowingÅhlberg (2020and2021b), I present eight examples of the
best wild edible plants that have 1) extensive distributions, 2) long his-
tory of use, and 3) phytochemical and toxicological research to guaran-
tee that they promote health.
1.1.2 The name-dropping level of listing minerals,
vitamins, and phytochemicals
According to Yeung et al. (2019), research on wild and cultivated edi-
ble plants may be divided roughly into two different phases: The 20th
century and the 21st century: In the 20th-century, research focused on
minerals and vitamins. In the 21st century, the research focus of WEP
has been on phytochemicals and other compounds that plants produce
to protect themselves andwhich often, not always, happen to promote
human health and longevity.
The research on phytochemicals started about 30 years ago. It has
grown exponentially. Most research on phytochemicals in nutrition is
from the 21st century.
It is a common practice to do name dropping of someminerals, vita-
mins, and phytochemicals.Without anymore profound knowledge, the
reader may become impressed but confused.
For example, Harford (2019) wrote a book on edible and medici-
nal wild plants of Britain and Ireland. Harford (2019) names phyto-
chemicals in connection with some plants, such as flavonoids, phenols,
242 ÅHLBERG
F IGURE 1 Stinging nettle (Urtica dioica) shoots in spring.
According to Åhlberg (2021), shoots contain at least 147
health-promoting ions and compounds, of which at least 32 prevent
Alzheimer’s disease. Photo courtesy of the publisherWild Edibles and
the authorMauri Åhlberg
rutin, and so forth. Nothing is detailed about how they promote health,
according to empirical research.
1.1.3 A profound level of using experimental
research results of health-promoting effects minerals,
vitamins, and phytochemicals
A profound level is (1) to give proper research references for each
health-promoting mineral, vitamin, primary metabolite, and secondary
metabolite (phytochemical); (2) to make explicit is the knowledge cre-
ated by experiments or not; (3) what kinds of health claims researchers
make? I rarely trust only one research report. Researchers test earlier
results and build upon themost relevant, valid, and reliable research.
I trust on careful reviews, in which the reader can check every
main claim. For example, Yeun et al. (2019) researched antioxidants
in natural dietary sources. They tried to find all research papers on
this theme. The oldest research article was from 1957. The number
of research articles grew slowly until the beginning of the 21st cen-
tury. Then it has grown exponentially. Almost all phytochemicals are
antioxidants. Rarely is antioxidant the only property of a phytochem-
F IGURE 2 Flowering yarrow (Achillea millefolium) in summer.
According to Åhlberg (2021), the aerial parts of the yarrow contain at
least 132 health-promoting ions and compounds, of which at least 24
prevent Alzheimer’s disease. Photo courtesy of the publisherWild
Edibles and the authorMauri Åhlberg
ical. Usually, those phytochemicals that researchers have experimen-
tally tested havemany other health-promoting properties. Zhang et al.
(2019) realized a gap between the high dosage demands of phyto-
chemicals in vitro studies and the low bioavailability of most phy-
tochemicals in actual human metabolism. In real life, humans eat in
their food mixtures of nutrients, including phytochemicals. Combina-
tions of phytochemicals exert synergistic effects in the human body,
increasing antioxidant capacity and anti-inflammatory effects, inter-
acting with the gut microbiome, and targeting the same and differ-
ent signaling pathways. According to Coman and Vodna (2020, p. 483),
recent evidence suggests that the real benefit of a diet rich in fruits
and vegetables stems from the synergistic effects of the complex mix-
ture of phytochemicals present in foods rather than from isolated
compounds.
According to Leitzmann (2016), there are “epidemiological data that
point to the excellent health potential of phytochemicals in humans.”
A high dietary intake of phytochemicals with wild edible vegetables,
fruits, berries, nuts, legumes, and whole-grain is associated with a
reduced risk for cancer, cardiovascular, and other diseases.
Tardío et al. (2016) has detailed species-specific tables of 38
Mediterranean species: mainly minerals, vitamins, and lipids. Phy-
tochemicals are tabled in many species at the group level: phe-
ÅHLBERG 243
F IGURE 3 Flowering self-heal (Prunella vulgaris) in summer.
According to Åhlberg (2021), the aerial parts of self-heal contain at
least 124 health-promoting ions and compounds, of which at least 27
prevent Alzheimer’s disease. Photo courtesy of the publisherWild
Edibles and the authorMauri Åhlberg
nolics (total) and flavonoids. Sometimes more specifically: phenolic
acids, hydroxycinnamic acids, and anthocyanins. Strangely, some well-
researched plants like stinging nettle (Urtica dioica) have no phyto-
chemicals tabled in this pioneering and otherwise excellent book.
Åhlberg (2020) lists health-promoting minerals, vitamins, and other
compounds like phytochemicals of over 90 species that have (1) a long
history of use, (2) globally extensive distribution, and (3) phytochem-
ical and toxicological research according to which these species are
safe to consume. Furthermore, he describes each chemical constituent
according to the latest empirical research, dating mainly from 2016 to
2020.
The following review summarizes 52 health-promoting chemical
constituents that all green edible plants share.
1.2 Descriptions of health-promoting chemical
constituents that all green edible plants share,
whether they are cultured or wild
The starting point of my research is WEP, but the results also apply
to cultivated edible plants. I describe each compound and ion in its
F IGURE 4 Flowers and fruits (rose hips) of rugosa rose (Rosa
rugosa). According to Åhlberg (2021), Rosa rugosa petals contain at
least 124 health-promoting ions and compounds, of which at least 28
prevent Alzheimer’s disease. According to Åhlberg (2021a), rose hips
of Rosa rugosa contain at least 122 health-promoting ions and
compounds, of which at least 32 prevent Alzheimer’s disease. Photo
courtesy of the publisherWild Edibles and the authorMauri Åhlberg
F IGURE 5 Flowering white clovers (Trifolium repens). According to
Åhlberg (2021), aerial parts of white clover contain at least 124
health-promoting ions and compounds, of which at least 26 prevent
Alzheimer’s disease Photo courtesy of the publisherWild Edibles and
the authorMauri Åhlberg
244 ÅHLBERG
F IGURE 6 Flowering red clover (Trifoliumpratense). According to
Åhlberg (2021), aerial parts of red clover contain at least 122
health-promoting ions and compounds, of which at least 27 prevent
Alzheimer’s disease. Photo courtesy of the publisherWild Edibles and
the authorMauri Åhlberg
F IGURE 7 Flowering fireweed (Epilobium angustifolium).
According to Åhlberg (2021), aerial parts of red clover contain at least
122 health-promoting ions and compounds, of which at least 27
prevent Alzheimer’s disease. Photo courtesy of the publisherWild
Edibles and the authorMauri Åhlberg
F IGURE 8 Flowering dandelion (Taraxacum officinale). According
to Åhlberg (2021), aerial parts of dandelion contain at least 115
health-promoting ions and compounds, of which at least 21 prevent
Alzheimer’s disease. Photo courtesy of the publisherWild Edibles and
the authorMauri Åhlberg
vignette, which I divide into two parts: (1) What the compound or ion
means for humans and (2) its role in plants. The first part is needed
because I intend topromotehumannutrition, health, and longevity. The
second part is necessary because it contains evidence that all green
plants need the same ions and compounds in their lives. For maximum
credibility, all references are inside each vignette.
In the following vignettes of 52 compounds and ions, I explain (1)
what constituents all green edible plants have, (2) their role in human
health, and (3) their role in plants’ lives. The references are more con-
vincing when attached to their chemical constituent (an ion, a primary,
or a secondary metabolite). Research literature inside vignettes is sep-
arate from the references of the main body of the text. Inside the
vignettes, the references follow Åhlberg (2020). Only part of the con-
stituents is in Åhlberg (2020). Åhlberg (2020) did not show interest
in the role of phytochemicals and other constituents in plants. It is an
innovation in this article. Many phytochemicals and other constituents
are new findings in the literature of WEP. I have checked and updated
all vignettes.
ÅHLBERG 245
Health-promoting
phytochemicals and other
compounds and ions
Research articles supporting health claims. All scientific research claims are tentative, prone to continual testing,
checking, rechecking, and improvement.
Alpha-linolenic acid (1/52) For humans: According to Saini and Keum (2018), Stark et al. (2008), and Guil- Guerrero and Torija- Isasa (2016, p.
174), alpha-linolenic acid is an omega-3-polyunsaturated fatty acid. Alpha-linolenic acid has the following
health-promoting properties: (1) an essential fatty acid for human health; (2) cardioprotective; (3) anti-inflammatory;
(4) neuroprotective; (5) anticancer; and (6) in general, promotes health and prevents chronic diseases.
According to Gammone et al. (2019), omega-3 polyunsaturated fatty acids have the following health-promoting
properties: (1) essential in numerous cellular functions, such as signaling, cell membrane fluidity, and structural
maintenance; (2) regulate the nervous system; (3) regulate blood pressure; (4) regulate hematic clotting; (6) control
glucose tolerance; (6) inflammatory; and (7) antioxidant.WEP often containmore omega-3 polyunsaturated fatty
acids than omega-6 polyunsaturated fatty acids.
According to Stark et al. (2008, p. 326), alpha-linolenic acid is abundant in plant foods such as walnuts, canola oil,
flaxseeds, and green leafy vegetables.WEP have primarily green leaves.
In plants: According to He andDing (2020, pp. 1–2), He et al. (2020, pp. 1–3), and Fouillen et al. (2013, pp. 334–335), all
green land plants have at least the following unsaturated fatty acids: (1) oleic acid, (2) linoleic acid, and (3)
alpha-linolenic acid. All greenWEP have these three health-promoting fatty acids. He andDing (2020, pp. 1–2), He
et al. (2020, pp. 1–3), and Fouillen et al. (2013, pp. 334–335) add that oleic acid, linoleic acid, and alpha-linolenic acid
are (1) ingredients andmodulators of cellular membranes, (2) reserve of carbon and energy, (3) stocks of extracellular
barrier constituents, (4) precursors of various bioactivemolecules, and (5) regulators of stress signaling.
Fouillen, L. et al. 2013. The lipidworld concept of plant lipidomics. Advances in Botanical Research 67, 2013, 331–376.
Gammone,M. et al. 2019. Omega-3 polyunsaturated fatty acids: benefits and endpoints in sport. Nutrients, volume
11, article 46, 1–16.
Guil-Guerrero, J. L. & Torija-Isasa, M. E. (2016). Fatty acid profiles ofMediterraneanwild edible plants. InM.
Sánchez-Mata & J. Tardío (Eds.) MediterraneanWild Edible Plants (pp. 173–186). NewYork: Springer.
He,M. et al. 2020a. Plant unsaturated fatty acids: biosynthesis and regulation. Frontiers in Plant Science, volume 11,
article 390, 1–13.
He,M. &Ding, N. 2020b. Plant unsaturated fatty acids: multiple roles in stress response. Frontiers in Plant Science,
volume 11, article 562785, 1–15.
Saini, R. & Keum, Y. 2018. Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and
significance—A review. Life Sciences 203, 255–267.
Stark, A. et al. 2008. Update on alpha-linolenic acid. Nutrition Reviews 66(6), 326–332.
Antheraxanthin (2/52) For humans: According to Aziz et al. (2020) and Thomas and Johnson (2018), antheraxanthin and other xanthophylls
have the following health-promoting properties: (1) neuroprotective, (2) protect retina, (3) vital to eyesight, and (4)
heal wounds.
In plants: According to Goss and Latowski (2021), xanthophylls are inside chloroplasts of higher green plants. They
protect chlorophylls and photosynthesis from light damages.All greenWEP have the following xanthophylls:
violaxanthin, antheraxanthin, and zeaxanthin.
Aziz, E. et al. 2020. Xanthophyll: Health benefits and therapeutic insights. Life Sciences, volume 240, article 117104,
1–12.
Goss, R. & Latowski, D. 2021. Lipid dependence of xanthophyll cycling in higher plants and algae. Frontiers in Plant
Science, volume 11, article 455, 1–22.
Thomas, S. & Johnson, E. 2018. Xanthophylls. Advances in Nutrition 9(2), 160–162.
Ascorbic acid, and its salts,
ascorbates (3/52)
For humans: According to Baenas et al. (2019) and van Gorkom et al. (2019), ascorbic acid (Vitamin C) has many
biochemical functions, such as (1) an antioxidant, neutralization of free radicals; (2) in the absorption of iron from the
intestine; and (3) a cofactor in many enzymatic reactions, the synthesis, and protection from oxidation of collagen,
catecholamines, cholesterol, amino acids, and some peptide hormones.
In plants: According to Li et al. (2021), Smirnoff (2018), Ali et al. (2017), and Gallie (2013), for green plants, ascorbic
acid (1) is an antioxidant, (2) is essential for the regulation of photosynthesis, (3) takes part in photoprotection, (4)
takes part in cell expansion, (5) takes part in plant development, (6) leaves are a good source of ascorbate but dry seeds
and dormant buds have little or no ascorbate.
Ali, R. et al. 2017. Physiological studies on the interactive effects of lead and antioxidants onCarum carvi plant.
Egyptian Journal of Botany 57(2), 317–333.
Gallie, D. 2013. Ascorbic acid: amultifunctional molecule supporting plant growth and development. Scientifica,
volume 2013, article 795964, 1–24.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology
63(1), 210–227.
Smirnoff, N. 2018. Ascorbic acidmetabolism and functions: A comparison of plants andmammals. Free Radical
Biology andMedicine 122, 116–129.
(Continues)
246 ÅHLBERG
Health-promoting
phytochemicals and other
compounds and ions
Research articles supporting health claims. All scientific research claims are tentative, prone to continual testing,
checking, rechecking, and improvement.
Beta-carotene (4/52) For humans: According to Coronel et al. (2019, p. 11), and Amesa (2018), beta-carotene has the following
health-promoting properties: (1) anti-obesity decreases obesity by promoting fatty acid oxidation in adipocytes and
other tissues, (2) the primary precursor of Vitamin A and retinoic acid, and (3) promotes general health and longevity.
In plants: According to Sun et al. (2018, p. 62), every chloroplast in green plants contains beta-carotene. The chloroplast
carotenoids such as beta-carotene are in the thylakoidmembranes for light-harvesting and photoprotection. Every
greenwild edible plant has beta-carotene. According to Sun et al. (2018, p. 59), plants produce, among others, the
following carotenoids: lycopene, alpha-carotene, beta-carotene, antheraxanthin, lutein, neoxanthin, violaxanthin, and
zeaxanthin. According to Bulda et al. (2008), plant seeds contain carotenes (including beta-carotene), xanthophylls,
and chlorophyll. Humans get beta-carotene from their food. The primary producer of beta-carotene is green plants.
According to Li et al. (2021), most beta-carotene accumulates in leaves.
Ames, B. 2018. Prolonging healthy aging: Longevity vitamins and proteins. PNAS 115(43), 10836–10844.
Bulda, O. et al. 2008. Spectrophotometric measurement of carotenes, xanthophylls, and chlorophylls in extracts from
plant seeds. Russian Journal of Plant Physiology 55(4), 544–551.
Coronel, J. et al. 2019. β-carotene in obesity research: technical considerations and current status of the field.
Nutrients 11(842), 1–19.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Sun, T. et al. 2018. Carotenoidmetabolism in plants: the role of plastids. Molecular Plant 11, 58–74.
Beta-sitosterol (5/52) For humans: According to Babu and Jayaraman (2020), Esposito et al. (2019), and Trautwein andDemonty (2007, p.
259), beta-sitosterol promotes human health in the followingways: (1) antioxidant, (2) antimicrobial, (3)
anti-inflammatory, (4) regulates immune response, (5) protects from respiratory diseases,( 6) hepatoprotective, (7)
lowers blood fat (lipid) level, (8) protects from fatty liver, (9) anticancer, (10) antidiabetic, (11) sedative, (12) analgesic,
(13) antipyretic (reduces fever), (14) anti-arthritic, and (15) wound healing.
In plants: According to Babu and Jayaraman (2020) andHarborne (2000), the cell wall of all green plants contains
phytosterols, of which 65% is beta-sitosterol. Therefore, all greenWEP contain beta-sitosterol.
Babu, S. & Jayaraman, S. 2020. An update on beta-sitosterol: A potential herbal nutraceutical for diabetic
management. Biomedicine & Pharmacotherapy, volume 131, article 110702, 1–8.
Esposito, S. et al. 2019. Therapeutic perspectives of molecules fromUrtica dioica extracts for cancer treatment.
Molecules 24, article 2753, 1–23.
Harborne, J. B. (2000). Arsenal for survival: secondary plant products. Taxon 49(3), 435–449.
Sayeed,M. et al. 2016. Critical analysis on characterization, systemic effect, and therapeutic potential of
beta-sitosterol: a plant-derived orphan phytosterol. Medicines, volume 3, article 29, 1–25.
Trautwein, E. & Demonty. I. 2007. Phytosterols: natural compoundswith established and emerging health benefits.
OCL 14(5), 259–266.
Biotin (6/52) For humans: According to TheNational Institutes of Health (2021), biotin (also calledVitamin B7 and Vitamin B8) is (1)
a cofactor for five enzymes that catalyze critical steps in themetabolism of fatty acids, glucose, and amino acids; (2)
takes part in gene regulation; (3) takes part in cell signaling; and (4) biotin also has other vital roles in human
metabolism. According to Tardy et al. (2020), biotin takes part in all cells’ energetic metabolism, including the brain and
nerve cells. Biotin participates in the nervous system’s normal functioning. Sirithanakorn and Cronan (2021) and
Alban (2011) state that biotin is a universal and essential cofactor in plants and humans. Human cells cannot produce
biotin. According to Alban (2011), human intestinal microbiota creates biotin, many foods contain biotin.
In plants: Biotin is (1) is an essential cofactor for CO2-manipulating enzymes and (2) takes part in the crucial metabolic
processes such as fatty acid and carbohydratemetabolism. According to Li et al. (2021), biotin (Vitamin B7) serves as a
cofactor for enzymes involved in carbohydrate and fatty acid metabolism. Biotin is a part of the compound that
participates in gene regulation, mitotic andmeiotic chromosome condensation, and DNA repair by rearrangement of
chromatin structure. All plants produce biotin.AllWEP contain biotin.
Alban, C. 2011. Biotin (Vitamin B8) synthesis in plants. Advances in Botanical Research 59, 39–66.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Sirithanakorn C. & Cronan J. 2021. Biotin, a universal and essential cofactor: Synthesis, ligation and regulation. FEMS
Microbiology Reviews, published online 11 Jan 2021.
Tardy, A. et al. 2020. Vitamins andminerals for energy, fatigue, and cognition: a narrative review of the biochemical
and clinical evidence. Nutrients, volume 12, article 228, 1–35.
TheNational Institutes of Health. (2021). Biotin. Fact Sheet for Health Professionals. Retrieved
fromhttps://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/
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ÅHLBERG 247
Health-promoting
phytochemicals and other
compounds and ions
Research articles supporting health claims. All scientific research claims are tentative, prone to continual testing,
checking, rechecking, and improvement.
Caffeic acid (7/52) For humans: According to Ekeuku et al. (2021), Kępa et al. (2018), and Habtemariam (2017), caffeic acid has the
following health-promoting properties: (1) one of themost potent antioxidants, (2) anti-inflammatory, (3)
antimicrobial, (4) anticancer, (5) prevents Alzheimer’s disease, and (6) prevents bone diseases.
In plants: According to Riaz et al. (2019, p. 9) andHüner andHopkins (2008), all plants synthesize caffeic acid. It is a
primary precursor for lignin synthesis in plants. Caffeic acid is actively involved in plant physiology andmechanisms of
(1) stress tolerance primarily utilized by plants for (2) the synthesis of lignin, which ultimately thickened cell walls, (3)
plants become resistant to sodium ions, and (4) plant become resistant to heavymetal stress, (5) it also reconciles the
absorption of high energy radiations in mesophyll cells under drought stress.
Ekeuku, S. et al. 2021. Effects of caffeic acid and its derivatives on bone: a systematic review. Drug Design,
Development and Therapy 15, 259–275.
Habtemariam, S. 2017. Protective effects of caffeic acid and the Alzheimer’s brain: An update. Mini Reviews in
Medicinal Chemistry 17(8), 667–674.
Hüner, N. &Hopkins,W. 2008. Introduction to plant physiology. NewYork:Wiley
Kępa,M. et al. 2018. Antimicrobial potential of caffeic acid against Staphylococcus aureus clinical strains. BioMed
Research International, volume 2018, article 7413504, 1–9.
Riaz, U. et al. 2019. Prospective roles andmechanisms of caffeic acid in counter plant stress: amini review. Pakistan
Journal of Agricultural Research, volume 32(1), 8–19.
Calcium (8/52) For humans: According to Kirk et al. (2021), National Institutes of Health (2021), Zoroddu (2019), Beto (2015), and
Peacock (2010): (1) Calcium is an essential nutrient necessary for many functions in the human health. Calcium is the
most abundantmineral in the body; 99% is in teeth and bone. Only 1% is in blood serum. (2) The blood serum calcium
level is tightly regulated to remain within normal range by a complexmetabolic process. (3) Humans need adequate
calcium levels throughout the life cycle. (4) Calciummetabolism involves other nutrients, including protein, Vitamin D,
and phosphorus. Calciummetabolism is a collaborative effort between calcium, phosphorus, Vitamin D, and protein.
Calcium consumed in natural food containsmany other nutrients and should be the primarymethod of intake. (5)
Calcium is an essential component of bone health. Inadequate intakemay change bonemineral density, particularly in
the elderly. (6) Bone formation andmaintenance is a lifelong process. (7) Research has shown that adequate calcium
intake can reduce the risk of fractures, osteoporosis, and diabetes. (8) Calcium takes part in vascular contraction. (9)
Calcium takes part in vasodilation. (10) Calcium takes part in muscle functions. (11) Calcium takes part in nerve
transmission. (12) Calcium takes part in intracellular signaling. (13) Calcium takes part in hormonal secretion. (14)
Calcium plays a role in maintaining normal bodyweight and decreasing the risk of obesity. (15) According to Huang
et al. (2020, p. 826), both green flowering plants and humans need calcium (Ca). Humans need four timesmore calcium
(Ca) than plants. It is difficult to get enough calcium (Ca) only fromWEP. TheMediterranean diet provides enough
calcium, Vitamin D, phosphorus, and protein when humans eat fish, goat cheese, yogurt, nuts, seeds, andWEP.
In plants: According to Taneja and Upadhyay (2021), García-Caparrós et al. (2018), Karthika et al. (2018),White and
Broadley (2003), calcium (Ca) is a crucial plant nutrient. Calcium is a divalent cation (Ca2+).Calcium hasmany vital
roles in the plants’ life: (1) Calcium takes part in cell walls andmembranes’ structures. Calcium is a constituent of the
middle lamella of cell walls. Thus, calcium takes part in themaintenance of membrane integrity in cell walls and
membranes. (2) Calcium takes part in the control of plant development. (3) Calcium is a counter-cation for inorganic
and organic anions in the vacuole. (4) Calcium is an intracellular messenger in the cytosol. (5) Calcium is amessenger in
metabolic regulation, and (6) Calcium is a cofactor of enzymes involved in themetabolism of adenosine triphosphate
(ATP) and phospholipids. ATP is necessary for energy production in cells. Phospholipids in plant cells have a crucial role
in transportingmaterials andmaintaining the structure of plants.
Beto, J. 2015. The role of calcium in human aging. Clinical Nutrition Research 4, 1–8.
García-Caparrós, P. et al. 2018. Ion homeostasis and antioxidant defense toward salt tolerance in plants. In
Hasanuzzaman,M. et al. (Eds.) Plant Nutrients and Abiotic Stress Tolerance. Singapore: Springer Nature, 415–436.
Huang S. et al. 2020. Plant nutrition for human nutrition: hints from rice research and future perspectives. Molecular
Plant 13, 825–835.
Karthika, K. et al. 2018. Biological functions, uptake and transport of essential nutrients in relation to plant growth. In
Hasanuzzaman,M. et al. (Eds.) Plant Nutrients and Abiotic Stress Tolerance. Singapore: Springer Nature, 1–50.
Kirk, B. et al. 2021. Nutrients tomitigate osteosarcopenia: the role of protein, vitamin D and calcium. Current Opinion
in Clinical Nutrition andMetabolic Care 24 (1), 25–32.
Peacock,M. 2010. Calciummetabolism in health and disease. Clinical Journal of the American Society of Nephrology
5, S23–S30.
Taneja, M. &Upadhyay, S. 2021. An introduction to the calcium transport elements in plants. In Upadhyay, S. (Ed.)
Calcium Transport Elements in Plants. London: Academic Press, 1–18.
TheNational Institutes of Health. (2021). Calcium. Fact sheet for health professionals. Retrieved from
https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
White, P. & Broadley,M. 2003. Calcium in plants. Annals of Botany 92, 487–511.
Zoroddu,M. & 2019. The essential metals for humans: a brief overview. Journal of Inorganic Biochemistry 195,
120–129.
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checking, rechecking, and improvement.
Carotenoids (9/52) For humans: According to Fakhr et al. (2020), Park et al. (2020),Woodby et al. (2020), Elvira-Torales et al. (2019), and
Metlicˇar et al. (2019), carotenoids have the following health-promoting properties: (1) antioxidant, (2)
anti-inflammatory, (3) anticancer, reduce the risk of cancer, (4) reduce cardiovascular diseases, (5) reducemacular
degeneration, (6) antidiabetic capacity, (7) modulate gene expression, (8) neuroprotective, (9) prevent Alzheimer’s
disease, (10) anti-obesity, and (11) promote skin health both internally and externally.
In plants: According toMaoka (2020), Sun et al. (2018), and Cogdell and Gardiner (1993), green plants need both
chlorophylls and carotenoids. Carotenoids are essential pigments in photosynthetic organs alongwith chlorophylls.
AllWEPhave carotenoids. Carotenoids act (1) as photo-protectors, (2) antioxidants, (3) color attractants, and (4)
precursors of plant hormones in the non-photosynthetic organs of plants. According to Fernández-Marín et al. (2017,
p. 1) and Bulda et al. (2008), plant seeds contain carotenoids, xanthophylls, and chlorophylls.
Bulda, O. et al. 2008. Spectrophotometric measurement of carotenes, xanthophylls, and chlorophylls in extracts from
plant seeds. Russian Journal of Plant Physiology 55(4), 544–551.
Cogdell, R. & Gardiner, A. 1993. Functions of carotenoids in photosynthesis. Methods in Enzymology 214, 185–193.
Fakhr, S. et al. 2020. Attenuation of Nrf2/Keap1/ARE in Alzheimer’s disease by plant secondarymetabolites: A
mechanistic review.Molecules, volume 25, article 4926, 1–45.
Fernández-Marín, B. et al. 2017. Seed carotenoid and tocochromanol composition of wild Fabaceae species is shaped
by phylogeny and ecological factors. Frontiers in Plant Science, volume 8, article 1428, 1–16.
Maoka, T. 2020. Carotenoids as natural functional pigments. Journal of NaturalMedicines 74, 1–16.
Park, H. et al. 2020. Anti-apoptotic effects of carotenoids in neurodegeneration.Molecules, volume 25, article 3453,
1–19.
Sun T. et al. 2018. Carotenoidmetabolism in plants: the role of plastids. Molecular Plant 11, 58–74.
Woodby, B. et al. 2020. Skin health from the inside out. Annual Review of Food Science and Technology 11, 235–254.
Chloride (10/52) For humans: According to Strohm et al. (2018): (1) Chloride (Cl−) is an essential ion for humanmetabolism; (2) chloride
(Cl−) produces hydrochloric acid (HCl) in the parietal cells of the stomach; (3) chloride (Cl−) is a component of gastric
juice; (4) hydrochloric acid (HCl) takes part in the process of digesting food; and (5) hydrochloric acid (HCl) takes part
in the defenses against unspecific pathogens. Most plant and animal food contain chlorides.
In plants: According to Huang et al. (2020, p. 826), chlorine and its ions, chlorides, are essential nutrients to plants. All
plant tissues have chlorides in their tissues.AllWEP contain chlorides. Rosales et al. (2020): Chloride (Cl−) has
beneficial macronutrient functions: (1) improve plant growth, (2) improve tissue water balance, (3) improve plant
water relations, (4) improve photosynthesis, (5) improvewater-use efficiency, (6) increase plant biomass, (7) improves
nitrogen use efficiency, (8) facilitates NO3
−utilization and improves nitrogen use efficiency in plants.
Huang S. et al. 2020. Plant nutrition for human nutrition: hints from rice research and future perspectives. Molecular
Plant 13, 825–835. https://doi.org/10.1016/j.molp.2020.05.007Rosales, M. et al. 2020. Chloride improves nitrate
utilization andNUE in plants. Frontiers in Plant Science, volume 11, article 442, 1–13.
Strohm, D. et al. 2018. Revised reference values for the intake of sodium and chloride. Annals of Nutrition and
Metabolism 72(1), 12–17.
Chlorophylls (11/52) For humans: According to Hayes and Ferruzzi (2020), Lachowicz et al. (2018, p. 1270), and Ferruzzi and Blakeslee (2007,
pp. 6–9), chlorophylls have the following health-promoting properties: (1) antioxidant, (2) cancer prevention, has
anticancer and antimutagenic effects, (3) regulation of detoxification, and (4) can help prevent degenerative diseases.
Hayes and Ferruzzi (2020) present detailedmolecular biological mechanisms of how these properties emerge.
In plants: According to Ke et al. (2021), chlorophylls participate in the absorption and transformation of light energy and
the primary photochemical reaction. In photosynthesis, plants create oxygen and glucose with light energy from
carbon dioxide andwater. Therefore, chlorophyll is an essential photosynthetic pigment. So far, five kinds of
chlorophylls have been identified, including chlorophylls a, b, c, d, and f, named according to the discovery order.
According to Cai et al. (2021), (1) chlorophylls are one of themost abundant organic pigments on the earth; (2) the
chemical structures of chlorophylls significantly affect the absorption of light and energy transfer efficiency. In
addition, chlorophylls interact with chloroplasts for light harvesting. According to Bulda et al. (2008), plant seeds
contain carotenoids, xanthophylls, and chlorophylls.
Bulda, O. et al. 2008. Spectrophotometric measurement of carotenes, xanthophylls, and chlorophylls in extracts from
plant seeds. Russian Journal of Plant Physiology 55(4), 544–551.
Cai, J. et al. 2021. Chlorophylls derivatives: Photophysical properties, assemblies, nanostructures and biomedical
applications. Materials Today, In Press, Corrected Proof, Available online 29 January 2021.
Hayes,M., and Ferruzzi, M. 2020. Update on the bioavailability and chemopreventativemechanisms of dietary
chlorophyll derivatives. Nutrition Research 81, 19–37.
Ke,W. et al. 2021. Chlorophylls. In Gao, K. et al. (Eds.) ResearchMethods of Environmental Physiology in Aquatic
Sciences. Singapore: Springer, 95–106.
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checking, rechecking, and improvement.
Citric acid (12/52) For humans: According to Donno et al. (2018, p. 6), citric acid is an antioxidant. According to Schnarrenberger and
Martin (2002, p. 869), humans also have the citric acid cycle in their cells’ mitochondria. According to Granchi et al.
(2019, p. 22), (1) salts of citric acid are citrates. Citrate is an essential metabolite and plays a pivotal role in maintaining
the acid-base balance, (2) citrate is a necessary bone component, (3) citrate serves to preserve the integrity of the
skeletal nano-andmicrostructures, (4) osteoblasts produce citrate and influence their differentiation and
functionality, (5) bone tissue is the primary source of citrate and is a leading actor in maintaining citrate homeostasis.
In plants: According to Braun (2021) and Schnarrenberger andMartin (2002), the citric acid cycle is a central element of
higher-plant for carbon, protein, and fatty acidmetabolism. The citric acid cycle happens insidemitochondria, which
provides energy for plant metabolism.AllWEP have citric acid. According to Kumar andDubey (2019), the citric acid
cycle produces biomolecules, such as secondarymetabolites (phytochemicals).
Braun, H. 2021. Enzymes: The two roles of complex III in plants. eLife, Plant Biology Structural Biology andMolecular
Biophysics, volume 10, article e65239.
Donno, D. et al. 2018. New findings in Prunus padus L. fruits as a source of natural compounds: characterization of
metabolite profiles and preliminary evaluation of antioxidant activity. Molecules, volume 23, article 725, 1–18.
Granchi, D. et al. 2019. Role of citrate in pathophysiology andmedical management of bone diseases. Nutrients,
volume11, article 2576, 1–30.
Kumar, P. & Dubey, K. 2019. Citric acid cycle regulation: backbone for secondarymetabolite production. In Gupta, V. &
Pandey, A. (Eds). New and Future Developments inMicrobial Biotechnology and Bioengineering.Microbial
SecondaryMetabolites Biochemistry and Applications. Amsterdam: Elsevier, 165–181.
Schnarrenberger, C. &Martin,W. 2002. Evolution of the enzymes of the citric acid cycle and the glyoxylate cycle of
higher plants: A case study of endosymbiotic gene transfer. European Journal of Biochemistry 269, 868–883.
Copper (13/52) For humans: According to Kaler (2021), copper (Cu) is an essential trace element. Copper participates as a cofactor for
many enzymes in the critical cellular processes.
In plants: According to Andresen et al. (2018), copper (Cu) is a tracemetal that is essential for all plants. Therefore, all
WEP contain copper (Cu).
Andresen, E. et al. 2018. Tracemetal metabolism in plants. Journal of Experimental Botany 69(5), 909–954.
Kaler, S. 2021. Inherited disorders of human coppermetabolism. In Pyeritz, R. et al. (Eds.) Emery and Rimoin’s
Principles and Practice ofMedical Genetics and Genomics (Seventh Edition). Metabolic Disorders. London:
Academic Press, 413–443.
Dietary fibers (prebiotics)
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BACKGROUND: According to Spacova et al. (2020), trillions of microbes inhabit the human body; collectively, they are
the humanmicrobiota. Thesemicrobes create complex ecosystems, which continually impact human health. For
example, intestinal microbes (probiotics) need dietary fibers (prebiotics) to produce vitamins and phytochemicals.
According toWang et al. (2020), plenty of phenolic compounds are part of the plant cell structures. According toWang
et al. (2020, pp. 3335–3336), intestinal microbes cause fermentation of plant cell structures and relievemore
phytochemicals for the human body than the free phytochemicals from the same plants.
For humans: According to Spacova et al. (2020), Yegin et al. (2020), Mohanty et al. (2018, p. 155), and Veronese et al.
(2018), dietary fibers (prebiotics) have the following health-promoting properties: (1) Dietary fibers are food for
intestinal microbiota (probiotics). That is why dietary fibers are also called prebiotics. In addition, the consumption of
dietary fibers from vegetables, includingWEP, is associatedwith higher intakes of vitamins, minerals, and
phytochemicals; (2) promotemental health; (3) anti-diarrhea; (4) promotes bowel function; (5) promote bone
mineralization; (6) reduce the risk of several chronic diseases; (7) reduce the risk of type 2 diabetes; (8) antibacterial;
(9) immune-modulatory effect, (10) anticancer (including pancreatic, gastric, esophageal, colon, endometrial, breast,
and renal cancer); (11) remove cholesterol, (12) lower risk of cardiovascular diseases; (13) anti-obesity; (14) facilitate
mineral absorption; (15) regulate lipid metabolism; (16) anti-inflammatory; and (17) promote intake of
health-promoting compounds, such as phytochemicals and antioxidants from the intestine.
In plants: According to Yegin et al. (2020), dietary fibers are plant polysaccharides resistant to digestion. Plant
polysaccharides have limited absorption in the human small intestine. However, they are partially or wholly
fermentable in the large intestine.
According to Zeng et al. (2017), “Polysaccharides are the principal components of plant cell walls and comprise their
structural framework.”
Spacova, I. et al. 2020. Future of probiotics and prebiotics and the implications for early career researchers. Frontiers
inMicrobiology, volume 11, article 1400, 1–10.
Veronese, N. et al. 2018. Dietary fiber and health outcomes: an umbrella review of systematic reviews and
meta-analyses. The American Journal of Clinical Nutrition 107, 436–444.
Wang, Z. et al. 2020. Review of distribution, extractionmethods, and health benefits of bound phenolics in food
plants. Journal of Agricultural and Food Chemistry 68, 3330–3343.
Yegin, S. et al. 2020. Dietary fiber: a functional food ingredient with physiological benefits. In Preuss, H. & Bagchi, D.
(Eds.) Dietary Sugar, Salt and Fat in HumanHealth. London: Academic Press, 531–555.
Zeng, Y. et al. 2017. Visualizing chemical functionality in plant cell walls. Biotechnology for Biofuels, volume 10, article
263, 1–16.
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Flavonoids (15/52) For humans: According to Devi et al. (2021), Rufino et al. (2021), Nam et al. (2020), Uddin et al. (2020),
Hernández-Rodríguez et al. (2019), Reis Ballard andMaróstica Junior (2019), and Sanches et al. (2019), flavonoids in
WEP have the following health-promoting properties: (1) antioxidant, (2) anti-inflammatory, (3) anti-viral, (4)
antibacterial, (5) protect in manyways cardio-vascular system, (6) anti-obesity, (7) anticancer, (8) increase endogenous
antioxidants and the activity of antioxidant enzymes, (9) maintain oxidative stress levels below a critical point in the
body, (9) suppress oxidants, (10) anti-Alzheimer, prevent and alleviate neurodegenerative disorders, (11) alleviate
immunological disorders, (12) alleviatemetabolic disorders, (13) antidiabetic, (14) improve testosterone production,
contributing to normal spermatogenesis and preventing age-related degenerative diseases associated with
testosterone deficiency, (15) extremely safe, with low toxicity and structural diversity, (16) can chelatemetal ions
(detoxification), (17) form various synergistic complexes, in which health-promoting properties increase in comparison
with free flavonoids.
In plants: According to Alseekh et al. (2020), (1) researchers have described over 8000 plant flavonoids. According to
Hutchings (2020, p. 142) and Brunetti al. (2018), flavonoids are vital for the growth control and UV protection of
green plants.All green land plants, includingWEP, have flavonoids.
Alseekh, S. et al. 2020.The style and substance of plant flavonoid decoration; towards defining both structure and
function. Phytochemistry, volume 174, article 112347, 1–15.
Brunetti, C. et al. 2018.Modulation of phytohormone signaling: a primary function of flavonoids in
plant–environment interactions. Frontiers in Plant Science, volume 9, article 1042, 1–8.
Devi, S. et al. 2021. Flavonoids: potential candidates for the treatment of neurodegenerative disorders. Biomedicines,
volume 9, article 99, 1–20.
Hutchings, J. 2020. Evolution and human’s attraction and reaction to colour: Food and health. Color Research and
Application 46, 140–145.
Martin, L. & Touaibia, M. 2020. Improvement of testicular steroidogenesis using flavonoids and isoflavonoids for
prevention of late-onsetmale hypogonadism. Antioxidants, volume 9, article 237, 1–17.
Nam, G. et al. 2020.Multiple reactivities of flavonoids towards pathological elements in Alzheimer’s disease:
structure–activity relationship. Chemical Science, volume 11, article 10243, 10243–10254.
Rufino, A. et al. 2021. Flavonoids as antiobesity agents: A review.Medicinal Research Reviews 41(1), 556–585.
Uddin,M. et al. 2020.Molecular insight into the therapeutic promise of flavonoids against Alzheimer’s disease.
Molecules, volume 25, article 1267. 1–29.
Folic acid, folates (16/52) For humans: According to the National Institute of Health (2019d), Centeno Tablante et al. (2019), and Kohlmeier
(2015, p. 620), in humans (folates, folic acid,Vitamin B9) functions as a coenzyme to synthesize nucleic acids (DNA
and RNA) andmetabolism of amino acids. It also has other vital roles in humanmetabolism. Sources include dark green
wild vegetables. In rich and developing countries, people who do not eat enough green plants suffer a lack of folates.
In plants: According to Li et al. (2021), Aiyswaraya et al. (2020), and Ravanel et al. (2011): (1)All green plants produce
folates. (2) Folates are coenzymes and electron donors in major cellular processes. (3) Folates take part in the
formation of essential biomolecules, such as (a) DNA (nucleic acids), (b) a transfer RNA, (c) pantothenate (Vitamin B5),
and (d) amino acids.
Aiyswaraya, K. et al. 2020. Review on folate in crop plants. International Journal of CurrentMicrobiology and Applied
Sciences 9(3), 2831–2836.
Li, Y. et al. 2021 Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Ravanel, S. et al. 2011.Metabolism of folates in plants. Advances in Botanical Research 59, 67–106.
Glutathione (17/52) For humans: According toMari et al. (2020),Minich and Brown (2019), and Pizzorno (2014), glutathione takes part in (1)
critical physiological processes; (2) maintenance of redox balance; (3) reduction of oxidative stress; (4) direct chemical
neutralization of singlet oxygen, hydroxyl radicals, and superoxide radicals; (5) themaintenance of appropriate
mitochondrial redox environment; (6) mitochondrial function andmaintenance of mitochondrial DNA (mtDNA; (7)
cofactor for several antioxidant enzymes; (8) themaintenance of appropriatemitochondrial redox environment; (9)
enhancement of metabolic detoxification; (10) neutralization of free radicals produced in liver metabolism of chemical
toxins; (11) regulation of the immune system; (12) neuroprotection; (13) transportation of mercury out of cells and the
brain; (14) cancer prevention; and (15) regeneration of Vitamins C and E.
The variation of glutathione levels of cultivated plants is wide. According toMinich and Brown (2019, pp. 10–12),
different plant species have different glutathione amounts. Researchers have found that, for example, asparagus,
avocado, cucumber, green beans, and spinach havemore glutathione than other researched plants. I have found no
research on glutathione levels ofWEP. Probably,WEP have similarly wide variations in glutathione levels. For optimal
quantities of different health-promoting compounds, such as glutathione, it is wise to eat traditional
Mediterranean-style boiled wild vegetable mixtures. According to Drinkwater et al. (2015), short boiling reduces very
little glutathione quantity.
In plants: According to Hasanuzzaman et al. (2020, pp. 16–17), all plant cells have glutathione. Glutathione is an
antioxidant and contains sulfur.
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Glutathione is a part of the plant’s antioxidant defense system, which has several antioxidants. According to Foyer
(2001), ascorbic acid and glutathione are themajor antioxidants in plant cells.
Drinkwater, J. et al. 2015. Effects of cooking on rutin and glutathione concentrations and antioxidant activity of green
asparagus (Asparagus officinalis) spears. Journal of Functional Foods 12, 342–353.
Foyer, C. 2001. Prospects for enhancement of the soluble antioxidants, ascorbate and glutathione. BioFactors 15,
75–78.
Hasanuzzaman,M. et al. 2020. Regulation of ROSmetabolism in plants under environmental stress: a review of recent
experimental evidence. International Journal ofMolecular Sciences, volume 21, article 8695, 1–42.
Mari, M. et al. 2020.Mitochondrial glutathione: recent insights and role in disease. Antioxidants, volume 9, article
909, 1–21.
Minich,M. & Brown, B. 2019. A review of dietary (phyto)nutrients for glutathione support. Nutrients, volume 11,
article 2073, 1–20.
Pizzorno, J. 2014. Glutathione! Integrativemedicine (Encinitas, Calif.) 13(1), 8–12.
Iron (18/52) For humans: Iron (Fe) is an essential tracemetal in humanmetabolism. According to Briguglio et al. (2021), most body
iron (Fe) circulates bound to specific proteins andmainly serves to synthesize hemoglobin for new red blood cells. The
central element of the hemoglobinmolecule is iron (Fe). Theminor part of iron is in other tissues, such asmuscles.
Plants containmuch iron (Fe), but plants’ non-heme iron is much less bioavailable than the heme iron from animal
tissues such as liver, meats, eggs and fishes, meats yolk of chicken eggs fishes, such as herrings.
In plants: According to Andresen et al. (2018), iron (Fe) is an essential tracemetal for all plants.AllWEP contain iron (Fe).
Andresen, E. et al. 2018. Tracemetal metabolism in plants. Journal of Experimental Botany 69(5), 909–954.
Briguglio, M. et al. 2021. The central role of iron in human nutrition: from folk to contemporarymedicine. Nutrients,
volume 12, article 1761, 1–17.
Lignins (19/52) For humans: According to Vinardell andMitjans (2017), lignins promote health in the followingways: (1) antioxidant, (2)
anti-obesity, (3) anti-diabetes, (4) anti-thrombosis, (5) anti-viral, and (6) anticancer.
In plants: According to Polo et al. (2020) and Cesarino et al. (2012), lignin is a hydrophobic and heterogeneous
biopolymer fundamental for (1) the development of an efficient water transport system in plants, (2) conferring
structural robustness, (3) conferring impermeability to conduits, (4) essential for plant stiffness, (5) the plant cell wall
contains lignin, mainly in vessels and fibers, 6) lignin forms chemical bonds with hemicellulose, which adheres to
cellulosemicrofibrils, (7) lignin’s ability to resist degradation due to its chemically complex structuremakes this
polymer an effective defensive barrier against herbivores and pathogens, (8) lignin provides physical support for
plants to stand upright, (9) lignin is essential for plant growth and development, for example, plant cell walls, (10) lignin
gives plants physical support to stand upright, and (11) lignin enables long-distancewater transport and solutes by
waterproofing the vascular tissue.Cesarino, I. et al. 2012. An overview of ligninmetabolism and its effect on biomass
recalcitrance. Brazilian Journal of Botany 35(4), 303–311.
Polo, C. et al. 2020. Correlations between lignin content and structural robustness in plants revealed by X-ray
ptychography. Scientific Reports, volume 10, article 6023, 1–11.
Vinardell, M. &Mitjans, M. 2017. Lignins and their derivatives with beneficial effects on human health. International
Journal ofMolecular Sciences, volume 18, article 1219, 1–15.
Linoleic acid (20/52) For humans: According to Guil Guerrero and Torija Isasa (2016, p. 174), linoleic acid is an omega-6-polyunsaturated
fatty acid. It is an essential fatty acid for human health.
In plants: According to He andDing (2020, pp. 1–2), He et al. (2020, pp. 1–3), and Fouillen et al. (2013, pp. 334–335), all
green land plants have at least the following unsaturated fatty acids: (1) oleic acid, (2) linoleic acid, and (3)
alpha-linolenic acid.All greenWEP have these three health-promoting fatty acids. Oleic acid, linoleic acid, and
alpha-linolenic acid are (1) ingredients andmodulators of cellular membranes, (2) reserve of carbon and energy, (3)
stocks of extracellular barrier constituents, (4) precursors of various bioactivemolecules, and (5) regulators of stress
signaling.
Fouillen, L. et al. 2013. The lipid world concept of plant lipidomics. Advances in Botanical Research 67, 2013,
331–376.
Guil-Guerrero, J. L. & Torija-Isasa, M. E. (2016). Fatty acid profiles ofMediterraneanwild edible plants. InM.
Sánchez-Mata & J. Tardío (Eds.), MediterraneanWild Edible Plants (pp. 173–186). NewYork: Springer.
He,M. et al. 2020. Plant unsaturated fatty acids: biosynthesis and regulation. Frontiers in Plant Science, volume 11,
article 390, 1–13.
He,M. &Ding, N. 2020. Plant unsaturated fatty acids: multiple roles in stress response. Frontiers in Plant Science,
volume 11, article 562785, 1–15.
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Lutein (21/52) For humans: According to Fuad et al. (2020), Stringham et al. (2019), and Calvo (2005), lutein has the following
health-promoting properties: (1) antioxidant, (2) anti-inflammatory, (3) hepatoprotective, (4) vital to healthy eyes,
prevention of eye diseases, (5) prevents osteoarthritis, (6) cancer prevention, (7) prevention of cardiovascular
diseases, (8) neuroprotective, (9) prevents Alzheimer’s disease, and (10) vital to healthy cognitive brain function. Fuad
et al. (2020, p. 1772) present biomolecular mechanisms for eight of these properties.
Lutein and zeaxanthin are essential dietary carotenoids for themacula in the eye, protecting against the development of
age-relatedmacular degeneration and cataracts. Moreover, these compounds have other health-promoting effects,
including immune enhancement and reduced risk of developing degenerative diseases such as cancer and
cardiovascular diseases. Humans get lutein from their food. The primary producer of lutein is green plants.
In plants: According to Sun et al. (2018, p. 62), every chloroplast in green plants contains lutein. The chloroplast
carotenoids such as lutein are in the thylakoidmembranes for light-harvesting and photoprotection. Therefore, every
greenwild edible plant has lutein.
Calvo,M. 2005. Lutein: a valuable ingredient of fruit and vegetables. Critical Reviews in Food Science andNutrition
45, 671–696.
Fuad, N. et al. 2020. Lutein: A comprehensive review on its chemical, biological activities and therapeutic potentials.
Pharmacognosy Journal 12(6S), 1769–1778.
Stringham, J. et al. 2019. Lutein across the lifespan: from childhood cognitive performance to the aging eye and brain.
Current Developments in Nutrition 3(7), 1–8.
Sun, T. et al. 2018. Carotenoidmetabolism in plants: the role of plastids. Molecular Plant 11, 58–74.
Manganese (22/52) For humans: According to TheNational Institutes of Health (2021), Balachandran et al. (2020), andMartins et al. (2020),
manganese (1) is an essential trace element that is naturally present in many foods, (2) is a cofactor for many enzymes.
In addition, manganese participates in (3) amino acidmetabolism, (4) cholesterol metabolism, (5) glucosemetabolism,
(6) carbohydratemetabolism, (7) reactive oxygen species scavenging, (8) bone formation, (9) reproduction, (10)
immune response, (11) in blood clotting, (12) manganese is essential for numerous vital processes, including nerve and
brain development and cognitive functioning.
According toMartins et al. (2020), the diet is the primary source of manganese (Mn) intake for humans. A balanced diet
like theMediterranean diet is the best because excess quantities of manganese (Mn) are toxic. Plant-based foods are
the best sources of manganese (Mn) in the diet. According to Huang et al. (2020, p. 826), plants have 400 timesmore
manganese (Mn) than in the human body. The unit is mg/kg.
In plants: According to Huang et al. (2020) and Lidon (2004), plants requiremanganese (Mn) uptake from the soil for
their physiological processes and growing. According to Lidon (2004), manganese (Mn) is an essential micronutrient
that plays a primary role in activating several enzymes leading to various secondary products, such as lignin and
flavonoids. In addition, manganese participates in the photosynthesis, biosynthesis of fatty acids and proteins.
According to Tavanti et al. (2021), plants treatedwithmicronutrients such asmanganese (Mn) show higher tolerance to
abiotic stress and better nutritional status. In addition, micronutrients such asmanganese (Mn), at low concentrations,
can elicit and activate antioxidative enzymes, non-oxidizingmetabolism, as well as sugar metabolism tomitigate
damage by oxidative stress.
Balachandran, R. et al. 2020. Brainmanganese and the balance between essential roles and neurotoxicity. Journal of
Biological Chemistry 295(19), 6312–6329.
Huang S. et al. 2020. Plant nutrition for human nutrition: hints from rice research and future perspectives. Molecular
Plant 13, 825–835.
Lidon, F. et al. 2004.Manganese accumulation in rice: implications for photosynthetic functioning. Journal of Plant
Physiology 161, 1235–1244.
Martins, A. et al. 2020.Manganese in the diet: bioaccessibility, adequate intake, and neurotoxicological effects.
Journal of Agricultural and Food Chemistry 68(46), 12893–12903.
TheNational Institutes of Health. (2021).Manganese. Fact Sheet for Health Professionals. Retrieved from
https://ods.od.nih.gov/factsheets/Manganese-HealthProfessional/ Tavanti, T. et al. 2021.Micronutrient fertilization
enhances ROS scavenging system for alleviation of abiotic stresses in plants. Plant Physiology and Biochemistry
160, 386–396.
Magnesium (23/52) For humans: According to Dominguez et al. (2021), Barbagallo et al. (2021), The National Institutes of Health (2021),
and Veronese et al. (2020), magnesium (Mg) is an abundant mineral in the body.Magnesium (Mg) has a crucial role in
cellular homeostasis and organ functioning. According to Dominguez et al. (2021), traditionally, magnesium (Mg) is
presented as a cofactor to 300 regulatory enzymes. This information comes from an old research article by Ebel and
Günther (1980). According to Barbagallo et al. (2021, p. 2), Dominguez et al. (2021), and de Baaij et al. (2015), two new
reliable sources list over 600 enzyme systems that regulate diverse biochemical reactions in the body, in which
magnesium (Mg) is a cofactor. These 600 enzyme systems regulate various biochemical reactions in the body,
including (1) energy production in cells, (2) protein synthesis, (3) DNA and RNA nucleic acid synthesis, (4) synthesis of
the antioxidant glutathione, (5)Mg ions participate in the transport of calcium (Ca) and potassium (K) ions through cell
membranes, (6) muscle contraction, (7) nerve impulse conduction, (8) blood glucose control, (9) blood pressure
regulation, (10) structural development of bone, and (11) normal heart rhythm.
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According to Barbagallo et al. (2021, p. 4), magnesium’s (Mg) intestinal absorption tends to fall with age, and this decline
may be one of the possible causes ofMg deficit with aging. Magnesium is naturally present in many foods, including
greenWEP and a dietary supplement.
In plants: All greenWEP havemagnesium (Mg) becausemagnesium is a central atom in the chlorophyll molecule. Thus,
the darker is the green color in plants, themore the plant probably contains chlorophyll andmagnesium. According to
Kleczkowski and Igamberdiev (2021), (1) much of total cellular magnesium (Mg) is required to synthesize chlorophyll
in photosynthetic tissues, (2) the rest of magnesium (Mg) participates in other vital processes in the cells, (3) many
plant enzymes require the binding of magnesium (Mg) for activity and regulation in processes such as phloem loading,
leaf senescence, stomata opening, and ionic balance of the cell.
According to Huang et al. (2020, p. 826), green plants are a goodmagnesium source.WEP as a part of the
Mediterranean diet provide plenty ofmagnesium.
Barbagallo, M. et al. 2021.Magnesium in aging, health, and diseases. Nutrients, volume 13, article 463, 1–20.
de Baaij, H. et al. 2015.Magnesium inman: implications for health and disease. Physiological Reviews 95, 1–46.
Dominguez, L. et al. 2021.Magnesium andHypertension in Old Age. Nutrients, volume 13, article 13, 1–32.
Ebel, H. & Günther, T. 1980.Magnesiummetabolism: A review. Journal of Clinical Chemistry and Clinical Biochemistry
18, 257–270.
Huang S. et al. 2020. Plant nutrition for human nutrition: hints from rice research and future perspectives. Molecular
Plant 13, 825–835.
Kleczkowski, L. & Igamberdiev, A. 2021.Magnesium signaling in plants. International Journal ofMolecular Science,
volume 22, article 1159, 1–23.
TheNational Institutes of Health. (2021).Magnesium. Fact Sheet for Health Professionals. Retrieved from
https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/
Melatonin 24/52 According to Cardinali (2021), all researched aerobic organisms havemelatonin.
For humans: According to Cardinali (2021), Cheng et al. (2021), Fatemeh et al. (2021), Hossain et al. (2021), Nous et al.
(2021), Mihardja et al. (2020), and Pourhanifeh et al. (2020), melatonin has the following health-promoting properties:
(1) antioxidant, (2) inflammatory, (3) chronobiotic, regulation of circadian rhythm, (4) antidiabetic, (5) prevents
malignancies, (6) cytoprotective, (7) prevents cardiovascular diseases, 98) anti-aging, (9) antihypertensive, (10)
regulates/modulates sleep, (11) modulates the immune system, (12) prevents osteoporosis, (13) anti-obesity, (14)
prevents metabolic syndrome, (15) prevents neurodegenerative diseases like Alzheimer’s disease.
In plants: According to Shi et al. (2017), melatonin is an essential pleiotropic molecule withmultiple physiological and
cellular actions in plants. In 1958, researchers foundmelatonin in the bovine pineal gland. In 1995, researchers
discoveredmelatonin in higher plants.
According to Arnao andHernández-Ruiz (2021) andNawaz et al. (2021), melatonin in plants is a multi-regulatory
molecule in stress situations. Thus, melatonin protects against individual biotic stressors (fungi, bacteria, viruses) and
abiotic stressors such as drought, waterlogging, extreme temperatures, salinity, alkalinity, and chemical pollutants in
soils (e.g., heavymetals, pesticides, among others), UV radiation, and combinations of the same.Melatonin acts as a
plant hormone in all these situations, protects against stress, and stimulates plant growth, photosynthesis,
germination, and other biochemical and physiological processes. According to Cheng et al. (2021), the quantity of
melatonin varies between species and cultivars. For example, according to Cheng et al. (2021), yarrow (Achillea
millefolium) has melatonin 340 ng/g and self-heal (Prunella vulgaris) 34 ng/ g.
Arnao,M. &Hernández-Ruiz, J. 2021.Melatonin as a plant biostimulant in crops and during post-harvest: a new
approach is needed. Online Version of Record before inclusion in an issue. Published online 17May 2021.
Cardinali, D. 2021.Melatonin and healthy aging. Vitamins andHormones 115, 67–88.
Cheng, G. et al. 2021. Plant-derivedmelatonin from food: a gift of nature. Food & Function 12(7), 2829–2849.
Fatemeh, G. et al. 2021. Effect of melatonin supplementation on sleep quality: a systematic review andmeta-analysis
of randomized controlled trials. Journal of Neurology, published online 08 January 2021.
Hossain, F. et al. 2021. Exploring themultifunctional role of melatonin in regulating autophagy and sleep tomitigate
Alzheimer’s disease neuropathology. Ageing Research Reviews, volume 67, article 101304, 1–14.
Mihardja, M. et al. 2020. Therapeutic potential of neurogenesis andmelatonin regulation in Alzheimer’s disease.
Annals of the NewYork Academy of Sciences. Published online 22 July 2020.
Nawaz, K. et al. 2021.Melatonin asmaster regulator in plant growth, development and stress alleviator for
sustainable agricultural production: current status and future perspectives. Sustainability, volume 13, article 294,
1–25.
Nous, A. et al. 2021.Melatonin levels in the Alzheimer’s disease continuum: a systematic review. Alzheimer’s
Research & Therapy, volume 13, article 52, 1–12.
Pourhanifeh,M. et al. 2020.Melatonin: new insights on its therapeutic properties in diabetic complications.
Diabetology &Metabolic Syndrome, volume, volume 12, article 30, 1–20.
Shi, H. et al. 2017. Editorial: Melatonin in plants. Frontiers in Plant Science, volume 8, article 1666, 1–2.
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Molybdenum (25/52) For humans: According to Belaidi and Schwarz (2017), molybdenum (Mo) is an essential trace element for humans. To
date, researchers have found fourmolybdenum-dependent enzymes in humans. These enzymes have amolybdenum
cofactor in the active center. In humans, themost crucial molybdenum enzyme catalyzes the terminal step in cysteine
catabolism—the oxidation of cytotoxic sulfite into sulfate. Therefore, a deficiency of themolybdenum cofactor results
in the loss of activities of all molybdenum-dependent enzymes, leading to severe neurodegeneration and death.
In plants: According to Andresen et al. (2018), molybdenum (Mo) is a tracemetal essential for all plants.AllWEP contain
molybdenum (Mo).
Andresen, E. et al. 2018. Tracemetal metabolism in plants. Journal of Experimental Botany 69(5), 909–954.
Molybdenum cofactor in humans: health, disease, and treatment. In Collins, J. (Ed.)Molecular, Genetic, andNutritional
Aspects ofMajor and TraceMinerals. London: Academic Press, 399–410.
Neoxanthin (26/52) For humans: According toMeléndez-Martínez (2019), Šircelj et al. (2018), and Terasaki et al. (2007), neoxanthin has the
following health-promoting properties: (1) antioxidant, (2) promotes immunity, (3) prevents cancers, (4) prevents
cardiovascular diseases, (5) prevents bone diseases, (6) prevents skin diseases, and (7) prevents eye diseases.
In plants: According to Sun et al. (2018, p. 62), every chloroplast in green plants contains neoxanthin. The chloroplast
carotenoids such as neoxanthin are in the thylakoidmembranes for light-harvesting and photoprotection. Every green
wild edible plant has neoxanthin. Humans get neoxanthin from their food. The primary producer of neoxanthin is
green plants.
Meléndez-Martínez, A. 2019. An overview of carotenoids, apocarotenoids, and vitamin A in agro-food, nutrition,
health, and disease. Molecular Nutrition Food Research. First published online: 12 June 2019.
Šircelj, H. et al. 2018. Lipophilic antioxidants in edible weeds from agricultural areas. Turkish Journal of Agriculture
and Forestry 42, 1–10.
Sun, T. et al. 2018. Carotenoidmetabolism in plants: the role of plastids. Molecular Plant 11, 58–74.
Niacin (27/52) For humans: Humans need niacin and the related compounds nicotinamide adenine dinucleotide (NAD) andNADP
/Nicotinamide Adenine Dinucleotide Phosphate) created by plants. According to Noctor et al. (2011, p. 158), in
relatively unprocessed foods, particularlymeats, NAD (Nicotinamide Adenine Dinucleotide) andNADP
(Nicotinamide Adenine Dinucleotide) provide themost significant part of humans’ available niacin. According to the
National Institutes of Health (2021), for humans, niacin (nicotinic acid,Vitamin B3) has the following
health-promoting properties: (1) many vital and complex roles in humanmetabolism, (2) human body tissues
transform absorbed niacin into the coenzymeNAD, and (3) more than 400 enzymes require NAD to catalyze reactions
in the human body, which is more than for any other vitamin-derived coenzyme. According to Noctor et al. (2011, p.
157), good niacin sources are, for example, potato, peas, tuna, and liver.
In plants: According to Noctor et al. (2011), plants can produce niacin and related compounds NAD andNADP. All cells
of every organism have these compounds.WEP contain niacin and related compounds NAD andNADP. NAD and
NADP are central compounds in cell redox and energymetabolism. According to Li et al. (2021), niacin and
nicotinamide are precursors for the compound that participates in fatty acid and carbohydratemetabolism. According
to Li et al. (2021), NAD+ is also a critical metabolite in cellular signaling reactions as it takes part in creating
compounds like cyclic ADP (Adenosine diphosphate) -ribose. ADP -ribosylation participates in cellular processes, such
as DNA repair, stress response, cell cycle control, and determining chromatin structure.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Noctor, G. et al. 2011. Biosynthesis of NAD and its manipulation in plants. Advances in Botanical Research 58,
153–201.
TheNational Institutes of Health 2021.Niacin. Fact sheet for health professionals. Retrieved
fromhttps://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/
Nickel (28/52) For humans: According to Zambelli and Ciurli (2013) and Zambelli et al. (2016), nickel (Ni) is a necessary trace element
for human health, especially nickel (Ni) is essential for health-promotingmicroorganisms that colonize the human guts.
In plants: According to Andresen et al. (2018), nickel (Ni) is an essential tracemetal for all plants.AllWEP contain nickel
(Ni).
Andresen, E. et al. 2018. Tracemetal metabolism in plants. Journal of Experimental Botany 69(5),
909–954.
Zambelli B. & Ciurli S. 2013. Nickel and human health. In Sigel A. et al. (Eds.) Interrelations between EssentialMetal
Ions andHumanDiseases. Metal Ions in Life Sciences, vol 13. Dordrecht: Springer, 321–357.
Zambelli, B. et al. 2016. Nickel impact on human health: An intrinsic disorder perspective. Biochimica et Biophysica
Acta (BBA)–Proteins and Proteomics 1864(12), 1714–1731.
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Nitrates (29/52) For humans: According to Butler (2015), Bryan and Ivy (2015), Sindelar andMilkowski (2012), Bahra et al. (2012), and
Bryan et al. (2012), nitrates and nitrites from plants are harmless to healthy adults, even indispensable nutrients.
According to the reviews of Raubenheimer et al. (2019) and Lundberg et al. (2018, p. 9), nitrates and nitrites that come
from plant food have the following health-promoting properties: (1) lower blood pressure, (2) improve endothelial
function, (3) increase exercise performance, (4) reverse of metabolic syndrome, (5) antidiabetic, (6) counteract
inflammation, and (7) promote homeostasis of the immune and vascular systems. Karwowska and Kononiuk (2020)
present a balanced overview of both benefits and possible dangers of nitrates in the human body. The threats are
mainly due to the use of nitrates and nitrites in meat products. Avoiding processedmeat products and using
Mediterranean-style boiled wild vegetable mixtures, benefits of nitrates can be optimized and risks minimized.
In plants: According to Hou et al. (2020),Wang et al. (2019), Noguero and Lacombe (2016), Stitt et al. (2002), and Stitt
(1999), (1) plant roots assimilate nitrate, nitrogen (N), from the soil; (2) nitrate is translocated to leaves, where nitrates
take part in amino acid and protein synthesis; (3) nitrate (NO3
-) is an essential source of nitrogen for plant
development andmetabolism; (4) nitrogen takes part in leaf photosynthesis; (5) nitrogen takes part in synthesizing
numerous cellular components, such as (a) chlorophyll and (b) nucleic acids; (6) nitrates take part in the pH regulation;
(5) nitrates take part in the sugar supply of the leaves; (6) nitrate is also a signal molecule controllingmany
physiological processes, plant growth, and crop yield; (7) nitrate participates in the regulation of lateral roots
development and architecture; (8) nitrate participates in the regulation of leaf development; (9) nitrate participates in
the flowering induction, and (10) nitrate participates in seed dormancy regulation; (11) nitrate is a signal molecule that
can trigger widespread changes in gene expression, resulting in changes in nitrogen and carbonmetabolism to
facilitate the uptake and assimilation of nitrate; (12) nitrogen contributes to plant defense responses by the regulation
of primarymetabolites of plants, such as carbohydrates, amino acids, and lipids; 13) nitrogen affects themechanical
strength of cell walls by changing the amount of plant cellulose and lignin to prevent pathogen penetration and limit
disease development.
Hou,W. et al. 2020. Diagnosis of nitrogen nutrition in rice leaves influenced by potassium levels. Frontiers in Plant
Science, volume 11, article 165, 1–13.
Noguero,M. & Lacombe, B. 2016. Transporters involved in root nitrate uptake and sensing byArabidopsis. Frontiers in
Plant Science, volume 7, article 1391, 1 - 7. Stitt, M. 1999, Nitrate regulation ofmetabolism and growth. Current
Opinion in Plant Biology 2(3), 178–186.
Stitt, M. et al. 2002. Steps towards an integrated view of nitrogenmetabolism. Journal of Experimental Botany
53(370), 959–970.
Wang,M. &al. 2019. Plant primarymetabolism regulated by nitrogen contributes to plant–pathogen interactions.
Plant and Cell Physiology 60(2), 329–342.
Oleic acid (30/52) For humans: According to Granado-Casa andDidac (2019), oleic acid is the primarymonounsaturated fatty acid present
in olive oil and nuts, two essential foods in theMediterranean diet. According to Gavahiana et al. (2019, p. 222), oleic
acid is a vital compound in extra virgin olive. It promotes healthy bacterial diversity in the gut.WEP often contain oleic
acid. According to Granado-Casa andDidac (2019) and Sales-Campo et al. (2013), oleic acid has the following
health-promoting properties: (1) prevents metabolic syndrome, (2) prevents high blood pressure, (3) prevents
overweight (obesity), (4) prevents hyperglycemia, (5) prevents atherogenic lipid profile, (6) prevents insulin resistance,
(7) prevents inflammation, (8) prevents prothrombotic alterations, (9) bactericidal, (10) fungicidal, (11) anticancer, and
(12) attenuation of the effects of autoimmune diseases.
In plants: According to He andDing (2020, pp. 1–2), He et al. (2020, pp. 1–3), and Fouillen et al. (2013, pp. 334–335), all
green land plants have at least the following unsaturated fatty acids: (1) oleic acid, (2) linoleic acid, and (3)
alpha-linolenic acid. Thus, all greenWEP have these three health-promoting fatty acids. Oleic acid, linoleic acid, and
alpha-linolenic acid are (1) ingredients andmodulators of cellular membranes, (2) reserve of carbon and energy, (3)
stocks of extracellular barrier constituents, (4) precursors of various bioactivemolecules, and (5) regulators of stress
signaling.
Fouillen, L. et al. 2013. The lipidworld concept of plant lipidomics. Advances in Botanical Research 67, 2013, 331–376.
He,M. et al. 2020. Plant unsaturated fatty acids: biosynthesis and regulation. Frontiers in Plant Science, volume 11,
article 390, 1–13.
He,M. &Ding, N. 2020. Plant unsaturated fatty acids: multiple roles in stress response. Frontiers in Plant Science,
volume 11, article 562785, 1–15.
Pantothenate (31/52) For humans: According toWebb and Smith (2011), for humans, pantothenate (Vitamin B5) is widespread in all
foodstuffs. Plants synthesize pantothenate.WEP contain pantothenate. Plants are an excellent dietary source of
pantothenate. In foods, the highest levels of pantothenate are in meat, dairy products, andmushrooms.
In plants: According to Li et al. (2021) andWebb and Smith (2011), pantothenate is an essential metabolite for all
organisms. Plants produce it. Humans need plant-created pantothenate. EveryWEP contains pantothenate.
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According to Li et al. (2021) andWebb and Smith (2011), pantothenate and its derivates take part (1) in central
carbohydrate and lipid metabolism; (2) in many secondarymetabolite biosynthetic pathways; (3) pantothenate is a
precursor of compounds that serve as enzymes involved in lipid biosynthesis and catabolism; 4) pantothenate is a
precursor of compounds that act in secondarymetabolite biosynthesis, for example, lignin biosynthesis; (5)
pantothenic acid promotes the vegetative and reproductive development of plants. Edible fruits, flowers, and seeds
containmore pantothenate than young leaves of edible plants.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Webb,M. & Smith, A. 2011. Pantothenate biosynthesis in higher plants. Advances in Botanical Research 58,
203–255.
Phenolic acids (32/52) For humans: According to Kumar and Goel (2019), Ca˘linoiu and Vodnar (2018), and Szwajgier et al. (2018), phenolic
acids have the following health-promoting properties: (1) antioxidants, (2) anticancer, (3) anti-inflammatory, (4)
antimicrobial, (5) antidiabetic, (6) neuroprotective, and (7) prevent Alzheimer’s disease.
According toMarchiosi et al. (2020) and Kumar and Goel (2019), phenolic acids are among themost widely distributed
phenolic compounds in plants. They are ubiquitous in both wild and cultured edible plants. Phenolic acids have
essential biological roles. Many of them take part in the biosynthesis of structural components of the cell wall. Others
are crucial for defense responses to pathogens and herbivores.
Marchiosi et al. (2020, p. 893) divide simple phenolic acids into three groups:Group 1: benzoic acid and benzoic acid
derivates, for example, (a) benzoic acid, (b) gallic acid, (c) protocatechuic acid, (d) p-hydroxybenzoic acid, and (e)
salicylic acid.Group 2: cinnamic acid and cinnamic acid derivatives, for example, (a) cinnamic acid, (b) p-coumaric acid,
(c) caffeic acid, (d) ferulic acid, and (e) sinapic acid.Group 3: others, for example, (a) catechol, (b) pyrogallol, and (c)
chlorogenic acid.
Ca˘linoiu, L. & Vodnar, D. 2018.Whole grains and phenolic acids: a review on bioactivity, functionality, health benefits
and bioavailability. Nutrients, volume 10(11), article 1615. 1–31.
Kumar, N. & Goel, N. 2019. Phenolic acids: Natural versatile molecules with promising therapeutic applications.
Biotechnology Reports, volume 24, article e00370, 1–10.
Marchiosi, R. et al. 2020. Biosynthesis andmetabolic actions of simple phenolic acids in plants. Phytochemistry
Reviews 19, 865–890.
Szwajgier, D. et al. 2018. Phenolic acids exert anticholinesterase and cognition-improving effects. Current Alzheimer
Research 15(6), 531–543.
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For humans: According to Zeb (2020), Soto-Vaca et al. (2012), Hamaguchi et al. (2009), andWojdyło et al. (2007), plant
phenolic compounds have the following health-promoting properties: (1) antioxidants, (2) may help prevent or delay
the onset of many diseases, (3) anti-inflammatory (can alter the expression of genes in the inflammatory pathway), (3)
antibacterial, (4) antihyperlipidemic, (5) anticancer, (6) cardioprotective, (7) antidiabetic, (8) neuroprotective, (9)
prevent Alzheimer’s disease, and (10) anti-aging.
In plants: According to de la Rosa et al. (2019), all edible plant tissues have phenolic compounds. They are “ubiquitously
distributed” secondarymetabolites.AllWEP contain phenolic compounds.
According toMaoka (2020), Hutchings (2020, p. 142), and Lin et al. (2016), phenolic compounds act as (1) antioxidants,
(2) structural polymers (lignin), (3) in photosynthesis, (4) attractants (flavonoids and carotenoids), (5) UV screens
(flavonoids), (6) vital in green plants in growth control (flavonoids), (7) signal compounds (salicylic acid and flavonoids),
and (8) defense chemicals (tannins and phytoalexins). According toWojdyło et al. (2007, p. 641), major phenolic
compounds include (1) apigenin, (2) caffeic acid, (3) p-coumaric acid, (4) ferulic acid, (5) isorhamnetin, (6) kaempferol,
(7) luteolin, (8) myricetin, and (9) quercetin.
de la Rosa, L. et al. 2019, Phenolic Compounds. In Yahia, E. (Ed.) Postharvest Physiology and Biochemistry of Fruits and
Vegetables. Cambridge:Woodhead Publishing, 253–271.
Hamaguchi, T. et al. 2009. Phenolic compounds prevent Alzheimer’s pathology through different effects on the
amyloid-beta aggregation pathway. The American Journal of Pathology 175(6), 2557–2565.
Hutchings, J. 2020. Evolution and human’s attraction and reaction to colour: Food and health. Color Research and
Application 46, 140–145.
Lin, D. et al. 2016. An overview of plant phenolic compounds and their importance in human nutrition and
management of type 2 diabetes. Molecules 21(10), article 1374, 1–19.
Maoka, T. 2020. Carotenoids as natural functional pigments. Journal of NaturalMedicines 74, 1–16.
Zeb, A. 2020. Concept, mechanism, and applications of phenolic antioxidants in foods. Journal of Food Biochemistry,
volume 44, article e13394, 1–22.
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Phosphorus (34/52) For humans: According to Peacock (2021) and TheNational Institutes of Health (2021), organic phosphorus (P) takes
part in essential cellular functions. These include (1) a part of the body’s vital energy source, ATP, (2) maintenance of
genetic informationwith nucleotides DNA and RNA, (3) intracellular signaling via cyclic adenosinemonophosphate,
(4) membrane structural integrity, (5) takes part in the regulation of gene transcription, (6) takes part in enzyme
activation, and (7) takes part in intracellular energy storage. In addition, many proteins and sugars in the body are
phosphorylated. Inorganic phosphorus (P) is in the human body as a weak acid, phosphoric acid, which has the
following health-promoting properties: (a) takes part in themaintenance of normal pH in extracellular fluid, (b) over
80% of the body phosphorus is present in the form of calcium phosphate crystals (apatite) that confer hardness to
bone and teeth, and (c) function as the significant phosphorus reservoir. Phosphorus is present in most foods and
closely parallels protein content. About 30% of dietary phosphorus is consumed as animal flesh and as vegetables. A
further 30% is consumed as dairy products, most of which is inorganic phosphorus.
In plants: According to Dissanayaka et al. (2021), inorganic phosphate (P) is an essential macronutrient required for
many fundamental processes in plants, including (1) photosynthesis, (2) respiration, (3) synthesis of nucleic acids (DNA
and RNA), (4) synthesis of proteins, and (5) synthesis of cellular membrane phospholipids.
Dissanayaka, D. et al. 2021. Recent insights into themetabolic adaptations of phosphorus-deprived plants. Journal of
Experimental Botany, volume 72(2), 199–223.
Peacock,M. 2021. Phosphatemetabolism in health and disease. Calcified Tissue International 108, 3–15.
TheNational Institutes of Health. (2021). Phosphorus. Fact Sheet for Health Professionals. Retrieved from
https://ods.od.nih.gov/factsheets/Phosphorus-HealthProfessional/
Phylloquinone (35/52) For humans: According to Chen et al. (2019), phylloquinone (Vitamin K) is a family of fat-soluble compounds,
phylloquinone, andmenaquinone. According to Li et al. (2021), most green vegetables contain high concentrations of
phylloquinone (Vitamin K1). According to Chen et al. (2019), humans get most Vitamin K1 from dark-green leafy
vegetables, while the latter, vitamin K2, is obtained from dairy products, meat, and eggs.
According to the National Institutes of Health (2018) and Gilles et al. (2017), phylloquinone (Vitamin K) has an active
role in (1) hemostasis (blood clotting), (2) bonemetabolism, and (3) other vital physiological functions.
In plants: According to Gu et al. (2021), Meyer et al. (2020), andOostende et al. (2011), all green plants synthesize
phylloquinone (Vitamin K1).All greenWEP have phylloquinone. In plants, phylloquinone participates in the
metabolism of tocopherols and chlorophyll. Phylloquinone is a lipophilic naphthoquinone found predominantly in
chloroplasts. Phylloquinone takes part in (1) electron transport and (2) folding proteins.
Gilles J. et al. 2017. Phylloquinone (vitamin K1): occurrence, biosynthesis and functions.Mini-Reviews inMedicinal
Chemistry 17(1), 1028–1038.
Gu, X. et al. 2021. Plasmamembrane phylloquinone biosynthesis in non-photosynthetic parasitic plants. Plants
Physiology. Published online 30 January 2021, 1–40.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Meyer, G. et al. 2020. Convergent evolution of plant specialized 1,4-naphthoquinones: metabolism, trafficking, and
resistance to their allelopathic effects. Journal of Experimental Botany, volume 72, no. 2 pp. 167–176. Advance
access publication, 1 December 2020, 167–176.
Oostende, C. et al. 2011. Vitamin K1 (phylloquinone): function, enzymes and genes. Advances in Botanical Research
59, 229–261.
TheNational Institutes of Health. (2021).Vitamin K. Fact Sheet for Health Professionals. Retrieved from
https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
Phytosterols (36/52) For humans: According to Babu and Jayarama (2020) andOgbe et al. (2015), phytosterols are plant steroid compounds
like animal cholesterol in structure and functions. Several animal and human studies show that phytosterols have the
following health-promoting properties: (1) antioxidant, (2) anticancer, (3) antidiabetic, (4) antimicrobial, (5)
immunomodulatory, (6) lower blood cholesterol level, and (7) lower “bad” LDL (low-density lipoprotein)-cholesterol
levels. The cholesterol-lowering effect of phytosterols is due to the direct inhibition of cholesterol absorption through
the displacement of cholesterol frommixedmicelles. Saturated phytosterols (stanols) aremore efficient in lowering
cholesterol levels than sterols (unsaturated).
In plants: According to Babu and Jayarama (2020), phytosterols are essential components of the plant cell wall.AllWEP
have phytosterols.
Babu, S. & Jayarama, S. 2020. An update on β-sitosterol: A potential herbal nutraceutical for diabetic management.
Biomedicine & Pharmacotherapy, volume 131, article 110702, 1–8.
Ogbe, R. et al. 2015. A review on dietary phytosterols: Their occurrence, metabolism and health benefits. Asian
Journal of Plant Science and Research 5(4), 10–21.
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checking, rechecking, and improvement.
plant proteins (37/52) For humans: According to Guyomarc’h et al. (2021), Itkonen et al. (2021), Merra et al. (2021), Loveday (2020), and
Krajcovicova-Kudlackova et al. (2005), (1) plant proteins lack essential amino acids needed in human nutrition. (2)
EatingWEP in theMediterranean diet provides amixture of healthy animal and plant proteins. (3) Plant proteins of
plant food prevent degenerative diseases.
In plants: According to Covarrubias et al. (2020), Fan et al. (2018), and Figueroa-Macías et al. (2021), all plants have
varying amounts of plant proteins. Every plant cell has plant protein. The amount of protein varies from plant tissue to
another tissue and from growth stages tomature structures.
Covarrubias, A. et al. 2020. The functional diversity of structural disorder in plant proteins. Archives of Biochemistry
and Biophysics, volume 680, article 108229, 1–17.
Fan,W. et al. 2018. Proteomics integratedwithmetabolomics: analysis of the internal causes of nutrient changes in
alfalfa at various growth stages. BMCPlant Biology, volume 18, article 78, 1–15.
Figueroa-Macías, J. et al. 2021. Plant growth-defense trade-offs: molecular processes leading to physiological
changes. International Journal ofMolecular Sciences, volume 22, article 69, 1–18.
Guyomarc’h, F. et al. 2021.Mixingmilk, egg and plant resources to obtain safe and tasty foodswith environmental and
health benefits. Trends in Food Science & Technology 108, 119–132.
Itkonen, S. et al. 2021. Partial replacement of animal proteins with plant proteins for 12weeks accelerates bone
turnover among healthy adults: a randomized clinical trial. The Journal of Nutrition 151(1), 11–19.
Krajcovicova-Kudlackova,M. et al. 2005. Health benefits and risks of plant proteins. BratislavaMedical Journal
106(6-7), 231–234.
Loveday, S. 2020. Plant protein ingredients with food functionality potential. Nutrition Bulletin 45(3),
321–327.
Merra, G. et al. 2021. Influence ofMediterranean diet on human gutmicrobiota. Nutrients, volume 13, article 7,
1–12.
Polyphenols (38/52) For humans: According to Reed and de Frietas (2020), Redd et al. (2020), Cassidy et al. (2020), Durazzo et al. (2019),
Gorzynik-Debicka et al. (2018), Qu et al. (2018), and Ignat et al. (2010), polyphenols have the following
health-promoting properties: (1) antioxidant, (2) anti-inflammatory, (3) regulate gene expression, (4) neuroprotective,
(5) prevents Alzheimer’s disease, (6) anticancer, (7) protect the cardiovascular system, prevention of cardiovascular
diseases, (8) reduce the risk of diabetes, (9) lower hypertension, (10) reduce the risk of diabetes, (11) prevent
metabolic abnormalities that may include hypertension, central obesity, insulin resistance, hypertension, and
imbalance of lipids in the blood, (12) reduceweight in overweight and obese individuals, (13) antitumor, via
anti-initiating, anti-promoting, anti-progression, and anti-angiogenesis actions, as well as by (14) modulating the
immune system and participate in the immunological defense, (15) antiallergic, (16) antimicrobial, and (17) antiviral.
The biological activity of polyphenols is strongly related to their antioxidant properties. They tend to reduce the pool
of reactive oxygen species (ROS) and neutralize potentially carcinogenic metabolites. Leri (2020) describes
biomolecular mechanisms on how polyphenols promote health.
In plants: According to Coman and Vodnar (2020, p. 483), over 8000 plant polyphenols are known. According to Šamec
et al. (2021), Singh et al. (2021), andMarranzano et al. (2018), all higher land plants have polyphenols (1) against
abiotic stressors, extreme temperatures, drought, flood, light, UV radiation, salt, and heavymetals. In addition, some
polyphenols protect plants against biotic stressors, for example, (2) against herbivores (plant-eating insects and other
animals, (3) against microorganisms. Polyphenolic compounds against abiotic and biotic stressors include phenolic
acids, flavonoids, stilbenoids, and lignans. In addition, some polyphenols take part in (4) plant growth, and (5) plant
development.AllWEP have polyphenols.
Cassidy, L. et al. 2020. Oxidative stress in Alzheimer’s disease: a review on emergent natural polyphenolic
therapeutics. Complementary Therapies inMedicine, volume 49, article 102294, 1–11.
Leri, M. 2020. Healthy effects of plant polyphenols: molecularmechanisms. International Journal ofMolecular
Sciences, volume 21, article 1250, 1–40.
Marranzano,M. et al. 2018. Polyphenols: plant sources and food industry applications. Current Pharmaceutical
Design 24, 4125–4130.
Redd, P. et al. 2020. Polyphenols in Alzheimer’s Disease and in the Gut–Brain Axis. Microorganisms, volume 8, article
199, 1–13.
Šamec, D. et al. 2021. The role of polyphenols in abiotic stress response: the influence ofmolecular structure. Plants,
volume 10, article 118, 1–24.
Singh, S. et al. 2021. Themultifunctional roles of polyphenols in plant-herbivore interactions. International Journal of
Molecular Sciences, volume 22, article 1442, 1–20.
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checking, rechecking, and improvement.
Polysaccharides (39/52) For humans: According to Gan et al. (2020), Mu et al. (2020), Yin et al. (2019), Olech et al. (2019), Liu et al. (2017), and Li
et al. (2015, 1557), plant polysaccharides have following health-promoting properties: (1) antioxidant, (2) immune
regulation, (3) anticancer, (4) anti-inflammatory, (5) antivirus, ( 6) protect harmful radiation, (7) hypoglycaemic effect,
and (8) prevent Alzheimer’s disease. Gan et al. (2020) andMu et al. (2020) show several molecular biological
mechanisms of how these properties emerge.
In plants: According to Zeng et al. (2017), “Polysaccharides are the principal components of plant cell walls and comprise
their structural framework.”
Gan, Q. et al. 2020.Modulation of apoptosis by plant polysaccharides for exerting anticancer effects. Frontiers in
Pharmacology, volume 11, article 792, 1- 19.
Liu, Q. al. 2017. Research advances in the treatment of Alzheimer’s diseasewith polysaccharides from traditional
Chinesemedicine. Chinese Journal of NaturalMedicines 15(9), 641–652.
Mu, S. et al. 2020. Antioxidant activities andmechanisms of polysaccharides. Chemical Biology &DrugDesign Early
ViewOnline Version of Record before inclusion in an issue.
Zeng, Y. et al. 2017. Visualizing chemical functionality in plant cell walls. Biotechnology for Biofuels, volume 10, article
263, 1–16.
Potassium (40/52) For humans: According to Jeremic et al. (2021), Pickering et al. (2021), The National Institutes of Health Potassium
(2021), McDonough and Youn (2017), and Demigné et al. (2004), potassium (K) is present in all body tissues. (1)
Potassiummaintains normal cell function. (2) Potassiummaintains intracellular fluid volume. (3) Potassium has a
crucial role in maintaining the electrochemical balance across cell membranes. (4) Potassium is vital to transmitting
nerve signals. Nerve signals lead, for example, skeletal muscle contraction, hormone release, and smoothmuscle and
heart contraction. (5) Potassium strongly relates to sodium, the primary regulator of extracellular fluid volume,
including plasma volume. (5) Potassium andmagnesium promote cardiovascular health. (6) High potassium intake
from vegetables and fruits protect against several diseases, for example, hypertension, stroke, cardiac dysfunctions,
renal damage, hypercalciuria, kidney stones, and osteoporosis. (7) High potassium intake from vegetables and fruits
maintains the acid-base status. (8) High potassium intake from vegetables and fruits maintains control of
carbohydratemetabolism or energy balance. According toMcDonough and Youn (2017), in evolution, our physiology
has developed for a high-potassium (K), low-sodium (Na) diet. Organisms have probably evolved in a geothermal
environment with high potassium(K)-to-sodium (Na) ratio, determining the cells’ evolution. According to Åhlberg
(2019, p. 67),WEP usually containmore potassium (K) than sodium (Na). According to Huang et al. (2020, p. 826),
green plants generally need 14,000mg/kg potassium (K). According to Huang et al. (2020, p. 826), humans need
potassium 4800mg/kg in general.
WEP contain practically alwaysmore potassium (K) than humans need. Eating aMediterranean diet provides enough
potassium.
In plants: According toWhite et al. (2021), Pandey andMahiwal (2020), and Pathak et al. (2020), potassium (K)
participates in (1) plant growth, (2) plant morphology, (3) plant anatomy, (4) plant metabolism, (5) many cellular
activities, (6) co-factoring for many enzymes, (7) many other physiological roles (8) stomatal opening for gas exchange,
(9) photosynthesis, and (10) themovement of photosynthates to developing tissues.
Mahmoud et al. (2017, p. 34, 40) researched potassium in soil and caraway leaves (Carum carvi). In the earth, the
potassium (K) level wasmuch lower than in the leaves. Caraway (C. carvi) takes potassium (K) from the soil and
concentrates it into the leaves. For humans, it is easy to get enough potassium (K) from the greenWEP. AllWEP
contain potassium (K).
Demigné, C. et al. 2004. Protective effects of high dietary potassium: nutritional andmetabolic aspects. The Journal of
Nutrition 134(11), 2903–2906.
Jeremic, D. et al. 2021. Therapeutic potential of targeting G protein-gated inwardly rectifying potassium (GIRK)
channels in the central nervous system. Pharmacology & Therapeutics, volume 223, article 107808, 1–28.
McDonough, A. & Youn, J. 2017 Potassium homeostasis: the knowns, the unknowns, and the health benefits.
Physiology 32, 100–111.
Pandey, G &Mahiwal, S. 2020. Role of potassium: an overview. In Pandey, G &Mahiwal, S. (Eds.) Role of Potassium in
Plants. Cham: Springer, 1–9.
Pathak, J. et al. 2020. Role of calcium and potassium in amelioration of environmental stress in plants. In
Roychoudhury, A. & Tripathi, D. (Eds.) Protective Chemical Agents in the Amelioration of Plant Abiotic Stress:
Biochemical andMolecular Perspectives. Hoboken, NJ: JohnWiley & Sons, 535–562.
Pickering, T. et al. 2021. Higher intakes of potassium andmagnesium, but not lower sodium, reduce cardiovascular risk
in the FraminghamOffspring Study. Nutrients, volume 13, article 269, 1–12.
TheNational Institutes of Health (2021). Potassium. Fact Sheet for Health Professional. Retrieved from
https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/
White, P. et al. 2021. Potassium use efficiency of plants. InMurrell, T. et al. (Eds.) Improving Potassium
Recommendations for Agricultural Crops. Cham: Springer, 119–146.
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checking, rechecking, and improvement.
Pyridoxine (41/52) For humans: According to TheNational Institutes of Health (2021), Parra et al. (2018), and Fitzpatrick (2011),
pyridoxine (Vitamin B6) is one of themost central molecules in living organisms’ cells. Pyridoxine is a critical cofactor
for various biochemical reactions that regulate primary cellular metabolism, impacting overall physiology.Humans
depend on pyridoxine initially produced by plants. Pyridoxine promotes human health in the followingways: (1) a
cofactor for more than 140 enzyme reactions; (2) a potent antioxidant; (3) many essential roles in metabolic and
developmental processes; (4) participates in cognitive development through the biosynthesis of neurotransmitters; (5)
promotes immune function (e.g., it enhances lymphocyte and interleukin-2 production), and (6) participates in
hemoglobin formation.
Fitzpatrick (2011) presents biomolecular mechanisms on how pyridoxine acts as a cofactor in many vital processes.
According to TheNational Institutes of Health (2020), excellent sources of Vitamin B6 include fish, beef liver, and
meat. According to Fitzpatrick (2011, p. 14), pyridoxine’s bioavailability varies. In general, animal products contain
more bioavailable forms of Vitamin B6, compared to plant food.
In plants: According to Fitzpatrick (2011), pyridoxine and its derivatives are derived primarily from plant cells. According
to Zhang et al. (2020), pyridoxine’s biosynthesis occurs in the cytosol of plants. The cytosol is an intracellular fluid.All
greenWEP produce pyridoxine in their cells. According to Fitzpatrick (2011, p. 14), leaves, flowers, fruits, and seeds
havemore pyridoxine than other parts of plants. According to Li et al. (2021), pyridoxine (Vitamin B6) is essential for
(1) postembryonic root development; (2) enlargement of aerial organs; (3) pyridoxine participates in diverse
enzymatic reactions, including transamination, aldol cleavage, decarboxylation, racemization, and elimination and
replacement reactions. These enzyme reactionsmainly involve amino acid synthesis andmetabolism, sugar, and fatty
acid metabolism; (4) pyridoxal phosphate-dependent enzymes play an essential role in the biosynthesis of biotin and
folate. According to Smith et al. (2007), pyridoxine takes part (1) in amino acid transformations in enzymes and (2)
secondarymetabolite pathways (e.g., the biosynthesis of alkaloids).
Fitzpatrick, T. 2011. Vitamin B6 in plants: more thanmeets the eye. Advances in Botanical Research 59, 1–38.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Parra, M. et al. 2018. Vitamin B6 and its role in cell metabolism and physiology. Cells, volume 7, article 84, 1–28.
Smith, A. et al. 2007. Plants need their vitamins too. Current Opinion in Plant Biology 10, 266–275.
TheNational Institutes of Health 2021.Vitamin B6. Fact Sheet for Health Professionals.Retrieved from
https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/
Zhang, J. et al. 2020. Gene cloning andmulti-angle analysis of pyridoxal reductase in tobacco plants. Plant Gene,
volume 22, article 100228, 1–7.
Riboflavin (42/52) For humans: According to TheNational Institutes of Health (2021), Jungert et al. (2020), Suwannason et al. (2020),
Thakur et al. (2017), and Powers (2003), riboflavin (Vitamin B2) has the following health-promoting properties: (1)
antioxidant, (2) anti-aging, (3) anti-inflammatory, (4) anti-nociceptive, (5) anti-migraine, (6) antianemia, (7) anticancer,
(8) antihyperglycemic, (9) anti-hypertension, (10) anti-diabetes, (11) prevents oxidative stress directly or indirectly,
(12) promotes iron absorption, (13) prevents mitochondrial dysfunction, (10) protects gastrointestinal tract, (14)
protects against cardiovascular disease, (15) prevents brain dysfunction, (16) antivirus, (17) participates in a diversity
of redox reactions central to humanmetabolism, (18) plays a role in thyroxinemetabolism, and (19) riboflavinmay be
the limiting nutrient, particularly in older people.
In plants: According to Li et al. (2021) and Fischer and Bacher (2011), all plants produce riboflavin.AllWEP have
riboflavin. According to Li et al. (2021) and Fischer and Bacher (2011), riboflavin derivatives have the following
functions in the cell: (1) serve as cofactors for many redox enzymes, (2) participate in the catalysis of specific
non-redox reactions, (3) cofactors of blue-light photoreceptors. Riboflavin is the precursor of the following cellular
cofactors: (a) flavin adeninemononucleotide (FMN) and (b) flavin adenine dinucleotide (FAD). Most
FMN/FAD-dependent enzymes catalyze redox reactions that are part of the primarymetabolism, such as
photosynthesis, fatty acid oxidation, the Krebs cycle, degradation of amino acids, and electron transport in
mitochondria. According to Fischer and Bacher (2011), riboflavin is an essential constituent of all living cells. The
absorption of animal-derived riboflavin is better than riboflavin from vegetables.
Fischer, M. & Bacher, A. 2011. Biosynthesis of Vitamin B2 and flavocoenzymes in plants. Advances in Botanical
Research 58, 93–152.
Jungert, A. et al. 2020. Riboflavin is an important determinant of vitamin B-6 status in healthy adults. The Journal of
Nutrition 150(10), 2699–2706.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Powers, H. 2003. Riboflavin (vitamin B-2) and health. The American Journal of Clinical Nutrition 77(6), 1352–1360.
Suwannasom, N. et al. 2020. Riboflavin: the health benefits of a forgotten natural vitamin. International Journal of
Molecular Sciences, volume 21, article 950, 1–22.
Thakur, K. et al. 2017. Riboflavin and health: A review of recent human research. Critical Reviews in Food Science and
Nutrition.
TheNational Institutes of Health 2021. Riboflavin. Fact Sheet for Health Professionals.Retrieved from
https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/
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checking, rechecking, and improvement.
Selenium (43/52) For humans: According to TheNational Institutes of Health (2021), Michalak et al. (2021), selenium (Se) is an essential
trace element for humans: (1) takes part in the structure of enzymatic proteins, (2) antioxidant, (2) anti-inflammatory,
(3) prevents DNA damage, (4) protects skin fromUV radiation, and (5) prevents aging of the skin. According to Cai
et al. (2019), a low selenium level is beneficial to the human body.ApplyingHuang et al. (2020, p. 826), all greenWEP
contain selenium. For example, theMediterranean diet provides both plant and animal products for optimal selenium
levels. Eggs, sea fishes, and dairy products like cheese contain selenium. According to Chen et al. (2021), Naderi et al.
(2021), and Terry et al. (2000), (1) there is a narrowmargin between the beneficial and harmful levels of selenium (Se),
and it has important implications for human health; (2) exposure to excess selenium is a risk factor for various brain
disorders; and (3) for those living in selenium-deficient areas, the use of selenium-rich foods is the safest and best
recommendation.
In plants: According to Chauhan et al. (2018),White (2018), and Guignardi and Schiavon (2017), Selenium (Se) is not an
essential element for plants, although it can benefit their growth and survival in some environments. According to
Huang et al. (2020, p. 826), all higher plants contain selenium. (2) Selenium hasmany beneficial effects on several plant
species. (3) Plants take up selenium (Se) mainly as selenate and selenite compounds. Plants use root high-affinity
membrane transporters that usually mediate the influx of sulfate and phosphate ions. (4) Once selenium is inside cells,
it can access the sulfur (S) assimilation pathway, becoming part of the selenium-amino acids. (5) Selenium at high
concentrations is toxic for plants due to oxidative stress. Selenium-amino acids are non-specifically incorporated into
proteins, which lose their folding and function as a result. (6) Plants have developed various strategies to copewith
selenium (Se) toxicity. They usually involve the conversion of Se-amino acids into less harmful volatile compounds.
Cai, Z. et al. 2019. Selenium, aging and aging-related diseases. Aging Clinical and Experimental Research 31,
1035–1047.
Chauhan, R. et al. 2018.Understanding seleniummetabolism in plants and its role as a beneficial element. Critical
Reviews in Environmental Science and Technology 49(21), 1937–1958.
Chen, N. et al. 2021. Selenium transformation and selenium-rich foods. Food Bioscience, volume 40, article 100875.
Guignardi, Z, & Schiavon,M. 2017. Biochemistry of plant selenium uptake andmetabolism. In Pilon-Smits E. et al.
(Eds.) Selenium in plants. Plant Ecophysiology, volume 11. Cham: Springer, 21–34.
Huang S. et al. 2020. Plant nutrition for human nutrition: hints from rice research and future perspectives. Molecular
Plant 13, 825–835.
Michalak,M. et al. 2021. Bioactive compounds for skin health: a review. Nutrients, volume 13, article 20, 1–31.
Naderi, M. et al. 2021. A comprehensive review on the neuropathophysiology of selenium. Science of The Total
Environment, volume 767, article 144329 1–17.
Schiavon,M. et al. 2017. Effects of selenium on plantmetabolism and implications for crops and consumers. In
Pilon-Smits E. et al. (Eds.) Selenium in plants. Plant Ecophysiology, Vol. 11. Cham: Springer, 257–275.
Terry, N. et al. 2000. Selenium in higher plants. Annual Review of Plant Physiology and PlantMolecular Biology 51,
401–432.
TheNational Institutes of Health 2021. Selenium. Fact Sheet for Health Professionals.Retrieved from
https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/White, O. 2018. Seleniummetabolism in plants.
Biochimica et Biophysica Acta (BBA)–General Subjects 1862(11), 2333–2342.
Silicon and silicates
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For humans: According toWu et al. (2021), Exley et al. (2019, p. 436), Oliveira et al. (2019), andMartin (2013), silicon (Si)
(silicates) have the following health-promoting properties: (1) facilitates excretion of toxic aluminum (Al) out of the
human body, (2) maintains bone health, (3) promotes the health of nails, hair, and skin, (4) promotes collagen synthesis,
(5) promotes bonemineralization, (6) reducesmetal accumulation in Alzheimer’s disease, (7) promotes immune
system health, and (8) reduces the risk for atherosclerosis. According to Huang et al. (2020, p. 826), green plants,
includingWEP, need 500mg silicon (Si) per kg. Humans need silicon 1mg/kg. Accordingly, it is easy to get enough
silicon by eatingWEP. SomeWEP are silicon accumulators. It is not dangerous to get extra silicon. The stem of field
horsetail (Equisetum arvense) contains 5%–8% silicic acid and silicates (salts of silicic acid). According toOliveira et al.
(2019), smooth sow thistle (Sonchus oleraceus) contains silicon (Si) and is a silicon-accumulator.
In plants: According to Hussain et al. (2021), Ahanger et al. (2020), Mandlik et al. (2020), and Tripathi et al. (2020), the
effects of silicon (Si) vary among plant species, but in general silicon (Si) (1) enhances water-use efficiency, (2)
increases the chlorophyll pigments, (3) enhances photosynthesis, (3) remedies nutrient imbalances, (4) increases the
uptake of nitrogen (N), phosphorus (P), calcium (Ca) andmagnesium (Mg), (5) counteracts abiotic stresses, (6)
counteracts water deficit, (7) counteracts temperature stresses, (8) counteracts shade stresses, (9) enhances plant’s
resistance to disease, (10) enhances the activity of enzymes, which help plants copewithmetal stress, (11) improves
biomass production, including stem length and leaf area, (12) the silicon content is generally higher in transpirational
organs such as leaves. On the other hand, the silicon content is lower in absorptive organs such as roots, indicating
that the evapotranspiration stream’s upward flow influences deposition. (13) Silicon deposits in the plant leaves: (a)
maintains photosynthesis, (b) increases the activity of antioxidant enzymes, (c) enhances the accumulation of
antifungal compounds, (d) enhances compartmentation of toxic heavymetals, (e) enhances the accumulation of
plant-protecting phenolics, (f) reduces transpiration, (g) enhances the accumulation of osmoticants, and (h) enhances
the development of mechanical barriers against herbivores. (14) In a stress situation, silicon deposits on the cell wall.
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(15) Silicon induces up-regulation of genes involved in secondarymetabolism, thereby increasing the biosynthesis and
accumulation of protective plant secondary compounds that provide various protective functions, including
antioxidant, antimicrobial, and insecticidal activities, metal chelation, and provision of cellular and structural
protection.
Ahanger, M. et al. 2020. Integration of silicon and secondarymetabolites in plants: a significant association in stress
tolerance. Journal of Experimental Botany 71(21), 6758–6774.
Hussain, S. et al. 2021. Foliar application of silicon improves growth of soybean by enhancing carbonmetabolism
under shading conditions. Plant Physiology and Biochemistry 159, 43–52.
Mandlik, R. et al. 2020. Significance of silicon uptake, transport, and deposition in plants. Journal of Experimental
Botany 71(21), 6703–6718.
Tripathi, D. et al. 2020. Silicon in plant biology: from past to present, and future challenges. Journal of Experimental
Botany 71(21), 6699–6702.
WuW. et al. 2021. Silicon-containingwater intake confers antioxidant effect, gastrointestinal protection, and gut
microbiotamodulation in the rodents. PLoSONE, volume 16(3), article e0248508, 1–17.
Sodium (45/52) For humans: According to Strohm et al. (2018), (1) quantitatively, sodium (Na+) and chloride (Cl−) are themost abundant
electrolytes in the extracellular space. (2) Almost all food contains sodium (Na) and chloride (Cl) ions. (3) Sodium (Na+)
and chloride (Cl−) are osmotically active in the extracellular fluid. (4) Sodium (Na+) and chloride (Cl−) maintain osmotic
pressure. (5) Sodium (Na+) and chloride (Cl−) maintainwater, electrolyte, and acid-base balance, (6) affect extracellular
volume, and (7) blood pressure. At the cellular level, (8) sodium (Na+) maintainsmembrane potential, (9) sodium (Na+)
facilitates the active transport of molecules across cell membranes. For instance, glucose is transported together with
sodium through a coupledmechanism (symport) in small intestinal enterocytes and renal tubular epithelial cells
In plants: According to Huang et al. (2020, p. 826), all plants contain sodium. AllWEP contain sodium. Sodium is not an
essential element for plants. According to Nieves-Cordones et al. (2016), the accumulation of Na+ at high
concentrations in the cytoplasm results in deleterious effects on cell metabolism, for example, on photosynthetic
activity in plants. Thus, Na+ is outside the cytoplasm. In plants, it is at high concentrations in vacuoles as osmoticum.
Na+ is not an essential element inmost plants, except in some halophytes.
Huang S. et al. 2020. Plant nutrition for human nutrition: hints from rice research and future perspectives. Molecular
Plant 13, 825–835.
Nieves-Cordones,M. et al. 2016. Roles and transport of sodium and potassium in plants. In Sigel A. et al. (Eds.) The
Alkali Metal Ions: Their Role for Life. Metal Ions in Life Sciences, Vol. 16. Cham: Springer, 291–324.
Strohm, D. et al. 2018. Revised reference values for the intake of sodium and chloride. Annals of Nutrition and
Metabolism 72(1), 12–17.
Sulfur (46/52) For humans: According to Francioso et al. (2020), Cˇolović et al. (2018), and Nimni et al. (2007), (1) Sulphur (S) takes part
in the vital metabolic processes as a component of proteins and vitamins. (2) Sulfur metabolism in humans is
complicated and has a central role in essential redox biochemistry. (3) Sulfur is ideal for redox biological reactions and
electron transfer processes. (4) Plant-created sulfur-containing amino acids are the primary source of sulfur in the
human body. The sulfur compounds in food include (a) amino acids includingmethionine, cysteine, and taurine; (b)
lipoic acid; (c) two vitamins: thiamine and biotin; (d) the glucosinolates and allylic sulfur compounds. (5) In the human
body, sulfur is in proteins and coenzymes such as CoenzymeA, biotin, lipoic acid, glutathione, and thiamine. (6)
Sulfur-containing amino acids take part in the production of intracellular antioxidants, like glutathione. (7) Sulfur, after
calcium and phosphorus, is themost abundant mineral element found in our body. Sulfur is available to us in our diets,
derived almost exclusively from proteins. Only two of the 20 amino acids in proteins contain sulfur. (8) Organic sulfur
compounds are effective antioxidants. (9) Organic sulfur compounds protect the human body from toxic metal ions.
In plants: According to Huang et al. (2020, p. 826), Abadie and Tcherkez (2019), Gigolashvili and Kopriva (2014), and
Tcherkez and Tea (2013): (1) all plants need sulfur. Sulfur is an essential nutrient for the synthesis of manymetabolites.
(2) All plants, includingWEP, produce amino acids that contain sulfur. (3) Plants create from inorganic sulfur
compounds amino-acids-containing-sulfur, like methionine and cysteine, antioxidants, cofactors, and secondary
metabolites glucosinolates. Hawkesford de Kok (2006): “Sulphur is taken up and transported around the plant
principally as sulphate, catalysed for themost part by a single gene family of highly regulated transporters. Additional
regulation occurs in the pathway of reduction of sulphate to sulphide and its incorporation into cysteine, which occurs
principally within the plastid.”
According to Tiku (2021), Cruciferae plants have glucosinolates. Glucosinolates protect plants from insects. For humans,
they are health-promoting compounds.WEP of Cruciferae include yellow rocket cress (Barbarea vulgaris), horseradish
Armoracia rusticana), and rocket (Eruca vesicaria).
According to Subramanian et al. (2020) and Lengbiye et al. (2020), Allium species have health-promoting sulfur
compounds like thiosulfinates.WEP of genus Allium include Chives (Allium schoenoprasum) and Ramsons (A. ursinum).
Garlic mustard (Alliaria petiolata, Cruciferae) contains a health-promoting sulfur compound, allyl isothiocyanate.
Abadie, C.& Tcherkez, G. 2019. Plant sulphurmetabolism is stimulated by photorespiration. Communications Biology,
volume 2, article 379, 1–7.
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phytochemicals and other
compounds and ions
Research articles supporting health claims. All scientific research claims are tentative, prone to continual testing,
checking, rechecking, and improvement.
Sulfur (46/52) (Continues) Cˇolović, M. et al. 2018. Sulphur-containing amino acids: protective role against free radicals and heavymetals.
CurrentMedicinal Chemistry 25, 1 – 12.
Francioso, A. et al. 2020. Chemistry and biochemistry of sulfur natural compounds: key intermediates of metabolism
and redox biology. OxidativeMedicine and Cellular Longevity, volume 2020, article 8294158, 1–27.
Gigolashvili, T. & Kopriva, S. 2014. Transporters in plant sulfurmetabolism. Frontiers in Plant Science, volume 5, article
442, 1–16.
Hawkesford,M. & de Kok, L. 2006. Sulphurmetabolism in plants. Plant, Cell and Environment 29, 382–395.
Lengbiye, E. et al. 2020. Antiviral activity, phytochemistry and toxicology of somemedically interesting Allium
species: amini review. International Journal of Pathogen Research 5(4), 64–77.
Nimni, M. et al. 2007. Arewe getting enough sulfur in our diet? Nutrition &Metabolism 4(24), 1–12.
Subramanian,M. et al. 2020. Prevailing knowledge on the bioavailability and biological activities of sulphur
compounds fromAlliums: a potential drug candidate. Molecules, volume 25, article 4111, 1–15.
Tcherkez, G. & Tea, I. 2013. 32S/34S isotope fractionation in plant sulphurmetabolism. NewPhytologist 200,
44– 3.
Tiku, A. 2021. Direct and indirect defence against insects. In Singh I. & Singh A. (Eds) Plant-Pest Interactions: From
MolecularMechanisms to Chemical Ecology. Singapore: Springer, 157–192.
Thiamin (47/52) For humans: According to TheNational Institutes of Health (2021), Fitzpatrick and Chapman (2020), and Rapala-Kozik
(2011), for humans, thiamin (thiamine,Vitamin B1) promotes health in the followingways: (1) participates in energy
metabolism, (2) participates in the growth, development, and function of cells; (3) participates in humanmetabolism
and is particularly important for proper brain functioning. The human brain needs plenty of glucose. According to
Polegato et al. (2019), thiamin (thiamine,Vitamin B1) is essential in glucosemetabolism.
In plants: According to Li et al. (2021) and Rapala-Kozik (2011), all plant cells produce thiamine, which is vital for plant
metabolism.AllWEP contain thiamin. According to Li et al. (2021) and Fitzpatrick and Chapman (2020), (1) thiamine
is a coenzyme inmetabolic pathways, particularly those involved in energy production and central metabolism,
including photosynthesis (carbon assimilation) and respiration. (2) Thiamine increases photosynthetic pigment
accumulation. (3) Thiamine takes part in plant stress protection, for example, protects from pathogens. (4) Thiamine
reducesmembrane permeability. (5) Thiamine activates antioxidant enzymes.
Thiamine-dependent enzymes are widely involved in (a) fatty acid synthesis, (b) branched-chain amino acid synthesis, (c)
glycolysis, (d) the Krebs cycle, (e) nitrogen assimilation, (f) the Calvin cycle, and (g) light-independent reactions of
photosynthesis that convert carbon dioxide and other compounds into glucose.
Fitzpatrick, T. & Chapman, L. 2020. The importance of thiamine (vitamin B1) in plant health: From crop yield to
biofortification. JBC Reviews 295(34), 12002–12013.
Li, Y. et al. 2021. Benefiting others and self: Production of vitamins in plants. Journal of Integrative Plant Biology 63(1),
210–227.
Polegato, B et al. 2019. Role of thiamin in health and disease. Nutrition in Clinical Practice 34(4), 558–564.
Rapala-Kozik,M. 2011. Vitamin B1 (thiamine): a cofactor for enzymes involved in themainmetabolic pathways and an
environmental stress protectant. Advances in Botanical Research 58, 38–91.
TheNational Institutes of Health. (2021). Thiamin. Fact Sheet for Health Professionals. Retrieved
fromhttps://ods.od.nih.gov/factsheets/Thiamin-HealthProfessional/
Tocopherols (48/52) For humans: According to TheNational Institutes of Health (2021), Azzi (2018), and Kamal-Eldin and Appelqvist (1996),
tocopherols (Vitamin E) have the following health-promoting properties: (1) antioxidants, (2) prevent cardiovascular
disease, (3) prevent neurodegenerative disease, (4) prevent macular degeneration, (5) prevent cancer, (6)
anti-inflammatory, (7) immune-boosting compound, (8) protect against non-alcoholic hepato-steatosis, (9) regulate
cell-signaling, and (10) modulate gene transcription.
In plants: According toMunné-Bosch and Alegre (2002), tocopherols and tocotrienols are lipid-solublemolecules with
several functions in plants. Tocopherols and tocotrienols are essential tomaintain plant cell membrane integrity.
Alpha-tocopherol is the primary form found in green parts of plants, while tocotrienols are in seeds.AllWEP contain
tocopherols. These compounds are antioxidants; thus, they protect the plant from oxygen toxicity. According toMa
et al. (2020), tocopherols are vital in green plants’ stress response.Kamal-Eldin, A. & Appelqvist, L. 1996. The
chemistry and antioxidant properties of tocopherols and tocotrienols. Lipids 31.
Ma, J. et al. 2020. Diverse roles of tocopherols in response to abiotic and biotic stresses and strategies for genetic
biofortification in plants. Molecular Breeding, volume 40(18), 1–15.
Munné-Bosch, S. & Alegre, L. 2002. The function of tocopherols and tocotrienols in plants. Critical Reviews in Plant
Sciences 21(1), 31–57
TheNational Institutes of Health. (2021).Vitamin E. Fact Sheet for Health Professionals. Retrieved
fromhttps://ods.od.nih.gov/factsheets/VitaminE-HealthProfessional/
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264 ÅHLBERG
Health-promoting
phytochemicals and other
compounds and ions
Research articles supporting health claims. All scientific research claims are tentative, prone to continual testing,
checking, rechecking, and improvement.
Violaxanthin (49/52) For humans: According to Šircelj et al. (2018) and Ames (2018), violaxanthin is a health-promoting antioxidant. In
addition, according to Aziz et al. (2020) and Thomas and Johnson (2018), violaxanthin and other xanthophylls have the
following health-promoting properties: (1) neuroprotective, (2) protect the retina, (3) vital to eyesight, and (4) heal
wounds.
In plants: According to Goss and Latowski (2021) and Sun et al. (2018, p. 62), xanthophylls are inside chloroplasts of
higher green plants. They protect chlorophylls and photosynthesis from light damages. The chloroplast xanthophylls
such as violaxanthin are in the thylakoidmembranes; they take part in light-harvesting and photoprotection.All green
WEP have the following xanthophylls: violaxanthin, antheraxanthin, and zeaxanthin. Humans get violaxanthin from
their food. Therefore, the primary producer of violaxanthin is green plants.
Ames, B. 2018. Prolonging healthy aging: Longevity vitamins and proteins. PNAS 115(43), 10836–10844.
Aziz, E. et al. 2020. Xanthophyll: Health benefits and therapeutic insights. Life Sciences, volume 240, article 117104,
1–12.
Goss, R. & Latowski, D. 2021. Lipid dependence of xanthophyll cycling in higher plants and algae. Frontiers in Plant
Science, volume 11, article 455, 1–22.
Sun, T. et al. 2018. Carotenoidmetabolism in plants: the role of plastids. Molecular Plant 11, 58–74.
Thomas, S. & Johnson, E. 2018. Xanthophylls. Advances in Nutrition 9(2), 160–162.
Xanthophylls (50/52) For humans: According to Aziz et al. (2020) and Thomas and Johnson (2018), xanthophylls have the following
health-promoting properties: (1) neuroprotective, (2) protect retina, (3) vital to eyesight, and (4) heal wounds.
In plants: According to Goss and Latowski (2021), xanthophylls are inside chloroplasts of higher green plants. They
protect chlorophylls and photosynthesis from light damages. In the xanthophyll cycles, violaxanthin transforms to
antheraxanthin and zeaxanthin during high light illumination. According to Bulda et al. (2008), plant seeds contain
carotenoids, xanthophylls, and chlorophylls. All greenWEP have the following xanthophylls: violaxanthin,
antheraxanthin, and zeaxanthin.
Aziz, E. et al. 2020. Xanthophyll: Health benefits and therapeutic insights. Life Sciences, volume 240, article 117104,
1–12.
Bulda, O. et al. 2008. Spectrophotometric measurement of carotenes, xanthophylls, and chlorophylls in extracts from
plant seeds. Russian Journal of Plant Physiology 55(4), 544– 551.
Goss, R. & Latowski, D. 2021. Lipid dependence of xanthophyll cycling in higher plants and algae. Frontiers in Plant
Science, volume 11, article 455, 1–22.
Thomas, S. & Johnson, E. 2018. Xanthophylls. Advances in Nutrition 9(2), 160–162.
Zeaxanthin (51/52) For humans: According to Liu et al. (2019b), Amesa (2018), Nwachukwu et al. (2016), and Roberts et al. (2009),
zeaxanthin has the following health-promoting properties: (1) potent antioxidant, (2) anti-lipogenesis, (4) anti-obesity,
(5) contribute to ocular health, through photoprotective effects, (6) promotes skin and eye health, and (7) promotes
health and longevity in general. Furthermore, Liu et al. (2019) describe amolecular biological mechanism, how
zeaxanthin is anti-obesity.
According to Aziz et al. (2020) and Thomas and Johnson (2018), zeaxanthin and other xanthophylls have the following
health-promoting properties: (1) neuroprotective, (2) protect retina, (3) vital to eyesight, and (4) heal wounds.
In plants: According to Goss and Latowski (2021), xanthophylls are inside chloroplasts of higher green plants. They
protect chlorophylls and photosynthesis from light damages. In the xanthophyll cycles, violaxanthin transforms to
antheraxanthin and zeaxanthin during high light illumination.All greenWEP have the following xanthophylls:
violaxanthin, antheraxanthin, and zeaxanthin.Aziz, E. et al. 2020. Xanthophyll: Health benefits and therapeutic
insights. Life Sciences, volume 240, article 117104, 1–12.
Goss, R. & Latowski, D. 2021. Lipid dependence of xanthophyll cycling in higher plants and algae. Frontiers in Plant
Science, volume 11, article 455, 1–22.
Thomas, S. & Johnson, E. 2018. Xanthophylls. Advances in Nutrition 9(2), 160–162.
zinc (52/52) For humans: According to TheNational Institutes of Health (2021), Joachimiak (2021), and Zhang et al. (2021), zinc (Zn)
promotes health in the followingways: (1) takes part in the catalytic activity of approximately 100–300 enzymes in the
cell metabolism, (2) antioxidant, (3) anti-inflammatory, (4) takes part in immune protection, (5) antiviral, (6) takes part
in DNA synthesis, (7) takes part in protein synthesis, (5) takes part in cell division, (6) takes part in wound healing, (7)
takes part in the proper sense of taste and smell, (8) prevents chronic diseases like diabetes, and (8) zinc supports
normal growth and development during pregnancy, childhood, and adolescence. Humansmust have their daily zinc
intake tomaintain a steady-state metabolism because the body has no specialized zinc storage system.
According to Joachimiak (2021, p. 4) and TheNational Institutes of Health (2021), whole-grain bread, cereals, legumes,
and other plant foods contain phytates that bind zinc and inhibit its absorption into the human body. The
bioavailability of zinc from grains and plant foods is lower than that of animal foods. TheMediterranean diet contains
both plant and animal food. For example, nuts, almonds, seeds, eggs, seafood, fish, andmeat contain bioavailable zinc.
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ÅHLBERG 265
Health-promoting
phytochemicals and other
compounds and ions
Research articles supporting health claims. All scientific research claims are tentative, prone to continual testing,
checking, rechecking, and improvement.
zinc (52/52) (Continues) In plants: According to Hassan et al. (2020) and Andresen et al. (2018): (1) Zinc (Zn) is one of six tracemetals that is
essential for all plants. (2) Zinc (Zn) regulates genes. (3) Zinc (Zn) takes part in membrane systems in chloroplasts. Lack
of zinc causes decreases in photosynthesis. (4) Zinc (Zn) takes part in plant resistance against drought stress by
regulating various physiological andmolecular mechanisms. (5) Zinc (Zn) improves seed germination. (6) Zinc (Zn)
improves plant water relations. (7) Zinc (Zn) improves cell membrane stability. (8) Zinc (Zn) improves osmolyte
accumulation. (9) Zinc (Zn) improves stomatal regulation. (10) Zinc (Zn) improves water use efficiency. (11) Zinc (Zn)
improves photosynthesis. (12) Zinc (Zn) interacts with plant hormones. (13) Zinc (Zn) increases the expression of
stress proteins, and (14) Zinc (Zn) stimulates the antioxidant enzymes for counteracting drought effects.
Andresen, E. et al. 2018. Tracemetal metabolism in plants. Journal of Experimental Botany 69(5), 909–954.
Hassan,M. et al. 2020. The critical role of zinc in plants facing the drought stress. Agriculture, volume 10, article 0396,
1–20.
Joachimiak,M. 2021. Zinc against COVID-19? Symptom surveillance and deficiency risk groups. Plos Neglected
Tropical Diseases, volume 15(1), article e0008895, 1–17.
TheNational Institutes of Health. (2021). Zinc. Fact Sheet for Health Professionals. Retrieved from
https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/
Zhang, Y. et al. 2021.Opportunities for plant-derived enhancers for iron, zinc, and calcium bioavailability: A review.
Comprehensive Reviews in Food Science and Food Safety 20, 652–685.
2 CONCLUSION AND FUTURE PERSPECTIVES
I found 52 chemical constituents of green edible plants from the
research literature, which (1) promote human health according to
experimental research and (2) are vital for plant structure and function
in the essential life processes.
We can safely assume that future researchers will find more chemi-
cal constituents like above in the coming years. There are many chemi-
cal constituents of green edible plants that no experimental researcher
has not yet tested. According toNunes et al. (2018, p. 110), researchers
have identified over 5000 individual dietary phytochemicals in vegeta-
bles, fruits, nuts, and whole grains. Nunes et al. (2018, p. 110) make an
educated guess: “muchmore are still unknown.”
I try to create public knowledge on why eating various green edi-
ble plants promotes health and longevity. Specialized researchers may
develop even deeper biomolecular mechanisms on how these plant
chemical constituents promote health. The concentration of com-
pounds and ions varies because of genetic and environmental varia-
tion, stages of development from seed to flowering, and fruiting plants,
whether in aerial parts or underground parts. That is why I prefer
Mediterranean-style boiled vegetable mixtures described in Guarrera
and Savo (2016). By eating mixtures of WEP, humans increase their
chance to get at least little of each health-promoting compound in
plants. Common scientific knowledge is thatmany plants and food con-
stituents generally promote health in small natural concentrations and
are unhealthy in high concentrations.
Applying Thakur et al. (2020, p. 341), Mediterranean-style boiled
wild vegetable mixtures are natural functional foods. However, this is
a hypothesis to be tested in future research.
From what I have already found, I have searched those chem-
ical constituents that prevent Alzheimer’s disease. From the 52
health-promoting chemical components of green edible plants, I
have found 10 compounds and ions, that according to experimental
research, prevent Alzheimer’s disease in some way: (1) caffeic acid,
(2) carotenoids, (3) flavonoids, (4) lutein, (5) melatonin, (6) phenolic
acids, (7) phenolic compounds, (8) polyphenols, (9) polysaccharides,
and (10) silicon and silicates. The shared plant chemical constituents
that prevent Alzheimer’s disease is a theme for a future overview
article.
The same could be done for any chemical constituent and any
disease that experimental researchers have tested. For example,
many chemical components that (1) prevent diseases like arthritis,
atherosclerosis, different cancers, or diabetes, and so forth; (2) protect
organs and systems like the cardiovascular system, kidneys, liver, and
so forth.
The main conclusion is that it is always wise to consume available
green edible plants, whether cultured or wild. Furthermore, their flow-
ers, fruits, and seeds often contain the same 52 chemical constituents
and many more health-promoting compounds and ions. However, it is
always better to check that any new part of an otherwise edible plant
does not contain any toxic compounds. For example, seeds of garlic
mustard (Alliaria petiolata) contain toxic erucic acid. Leaves and flowers
of garlic mustard (A. petiolata) suit in the Mediterranean boiled mixed
vegetables. According to Kolodziejczyk-Czepas and Liudvytska (2021,
pp. 589–590), rhubarb (Rheum rhaponticum and R. rhabarbarum) leaves
arepoisonousbecauseof toohighaquantityof oxalic acid.On theother
hand, eating some rhubarbpetioles promotes health becauseof the rel-
atively low level of oxalic acid and many health-promoting compounds
like flavonoids, such as quercetin, rutin, and phenolic acids like caffeic
acid and ellagic acid.
According to research literature, quantities of health-promoting
compounds vary between species and inside species. Future research
may determine which species in each ecosystem are worth a particu-
lar help to save sustainable sources of health-promoting compounds
and ions. Nowadays, some of the best sources of healthy food phyto-
chemicals are undervalued, like (1) purple loosestrife (Lythrum salicaria)
in North America, (2) Japanese knotweed (Fallopia japonica), and (3)
rugosa rose (Rosa rugosa) in some parts of Europe.
266 ÅHLBERG
CONFLICT OF INTEREST
The author confirms that he has no conflict of interest to declare for
this publication.
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How to cite this article: Åhlberg, M. K. (2021). A profound
explanation of why eating green (wild) edible plants promote
health and longevity. Food Frontiers, 2, 240–267.
https://doi.org/10.1002/fft2.106