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  • Louhiala, Pekka; Puustinen, Raimo; Hemilä, Harri (2013)
  • Untitled 
    Unknown author (2012)
  • Torp Karoliina (2011)
  • Harri Hemilä; Jaakko Kaprio (2011)
    Background: Antioxidants might protect against oxidative stress, which has been suggested as a cause of aging. Methods: The ATBC Study recruited males aged 50-69 years who smoked at least 5 cigarettes per day at the baseline. The current study was restricted to participants who were followed up past the age of 65. Deaths were identified in the National Death Registry (1445 deaths). We constructed Kaplan-Meier survival curves for all participants, and for four subgroups defined by dietary vitamin C intake and level of smoking. We also constructed Cox regression models allowing a different vitamin E effect for low and high age ranges. Results: Among all 10,837 participants, vitamin E had no effect on those who were 65 to 70 years old, but reduced mortality by 24% when participants were 71 or older. Among 2284 men with dietary vitamin C intakes above the median who smoked less than a pack of cigarettes per day, vitamin E extended life-span by two years at the upper limit of the follow-up age span. In this subgroup, the survival curves of vitamin E and no-vitamin E participants diverged at 71 years. In the other three subgroups covering 80% of the participants, vitamin E did not affect mortality. Conclusions: This is the first study to strongly indicate that protection against oxidative stress can increase the life expectancy of some initially healthy population groups. Nevertheless, the lack of effect in 80% of this male cohort shows that vitamin E is no panacea for extending life expectancy.
  • Hemilä Harri; Kaprio Jaakko; Albanes Demetrius; Virtamo Jarmo (2010)
    It has been proposed that moderate exercise may enhance the immune system. We evaluated whether physical activity at work or at leisure is associated with the risk of pneumonia, and whether the antioxidants vitamin E and β-carotene affect pneumonia risk in physically active people. A cohort of 16 804 male smokers aged 50 – 69 years and working at study entry was drawn from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, which examined the effect of vitamin E, 50 mg/day, and β-carotene, 20 mg/day, on lung and other cancers. Physical activity at work, and
  • Hemilä Harri; Virtatmo Jarmo; Albanes Demetrius; Kaprio Jaakko (2010)
    Background and Purpose: It has been proposed that moderate regular aerobic training may enhance immunocompetence, whereas excessive training may cause immunosuppression. We evaluated whether physical activity at work, or at leisure, is associated with the risk of the common cold, and whether the antioxidants vitamin E and β-carotene affect common cold risk in physically active people. Methods: A cohort of 14,401 men aged 50–69 yr and working at study entry was drawn from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, which examined the effect of vitamin E, 50 mg·d-1, and β-carotene, 20 mg·d-1, on lung cancer in smokers using a 2 × 2 factorial design. The trial was conducted in southwestern Finland in 1985–1993; the intervention lasted for 6.1 yr (median). Physical activity at work, and the type and frequency of leisure-time exercise were recorded at study entry. The subjects were questioned about common cold episodes 3× yr-1. We modeled the cumulative incidence of colds during a 2-yr follow-up period with Poisson regression, adjusting for potential confounders. Results: Physical activity at work and at leisure had no association with common cold risk. In subjects with physically load-bearing jobs, neither vitamin E nor β-carotene affected significantly the risk of common cold. In subjects carrying out heavy exercise at leisure, vitamin E and β-carotene increased the risk of colds when compared with placebo. Conclusions: Contrary to previous suggestions, moderate physical activity is not associated with lower risk of common cold in middle-aged male smokers. It has been previously proposed that antioxidant supplementation might be beneficial for subjects carrying out heavy exercise, but in our study vitamin E and β-carotene increased the risk of colds in subjects carrying out heavy exercise at leisure.
  • Hemilä Harri; Kaprio Jaakko; Albanes Demetrius; Heinonen Olli P; Virtamo Jarmo (2010)
    We evaluated the role of dietary vitamin C, vitamin E, and beta-carotene, as well as long-term vitamin E and beta-carotene supplementation, on the incidence of common cold episodes. A cohort of 21,796 male smokers was drawn from the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study, which examined the effects of 50 mg per day vitamin E and 20 mg per day beta-carotene on lung cancer. Diet and background characteristics were recorded at the study entry, and subjects were queried three times per year on common cold episodes. We modeled the total number of colds during a 4-year follow-up period with Poisson regression, adjusting for covariates of dietary intake. Dietary vitamins C and E and beta-carotene had no meaningful association with common cold incidence. Long-term vitamin E and beta-carotene supplementation had no overall effect. Among subjects 65 years of age or older, the incidence of colds was slightly lower in the vitamin E group (RR = 0.95; 95% CI = 0.90–1.00); this reduction was greatest among older city dwellers who smoked fewer than 15 cigarettes per day (RR = 0.72; 95% CI = 0.62–0.83). In this male smoking population, vitamins C and E and beta-carotene had no overall association with the incidence of common cold episodes.
  • Hemilä Harri (2009)
    Although the role of vitamin C in common cold incidence had been studied extensively, the level of vitamin C intake has not been unequivocally shown to affect the incidence of colds. In the present study the six largest vitamin C supplementation (≥ 1 g/d) studies, including over 5000 episodes in all, have been analysed, and it is shown that common cold incidence is not reduced in the vitamin C-supplemented groups compared with the placebo groups (pooled rate ratio (RR) 0.99; 95 % CI 0.93, 1.04). Consequently these six major studies give no evidence that high-dose vitamin C supplementation decreases common cold incidence in ordinary people. Nevertheless, the analysis was continued with the hypothesis that vitamin C intake may affect common cold susceptibility in specific groups of people. It was assumed that the potential effect of supplementation might be most conspicuous in subjects with low dietary vitamin C intake. The average vitamin C intake has been rather low in the UK and plasma vitamin C concentrations are in general lower in males than in females. In four studies with British females vitamin C supplementation had no marked effect on common cold incidence (pooled RR 0.95; 95 % CI 0.86, 1.04). However, in four studies with British male schoolchildren and students a statistically highly significant reduction in common cold incidence was found in groups supplemented with vitamin C (pooled RR 0.70; 95 % CI 0.60, 0.81). Thus, these studies with British males indicate that vitamin C intake has physiological effects on susceptibility to common cold infections, although the effect seems quantitatively meaningful only in limited groups of people and is not very large.
  • Hemilä Harri (2009)
    Placebo-controlled trials have shown that vitamin C supplementation decreases the duration and severity of common cold infections. However, the magnitude of the benefit has substantially varied, hampering conclusions about the clinical significance of the vitamin. In this paper, 23 studies with regular vitamin C supplementation (≥1 g/day) were analyzed to find out factors that may explain some part of the variation in the results. It was found that on average, vitamin C produces greater benefit for children than for adults. The dose may also affect the magnitude of the benefit, there being on average greater benefit from ≥2 g/day compared to 1 g/day of the vitamin. In five studies with adults administered 1 g/day of vitamin C, the median decrease in cold duration was only 6%, whereas in two studies with children administered 2 g/day the median decrease was four times higher, 26%. The trials analyzed in this work used regular vitamin C supplementation, but it is conceivable that therapeutic supplementation starting early at the onset of the cold episode could produce comparable benefits. Since few trials have examined the effects of therapeutic supplementation and their results have been variable, further therapeutic trials are required to examine the role of vitamin C in the treatment of colds.