Browsing by Subject "vitamin E"

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  • Hemilä, Harri; Kaprio, Jaakko (2011)
    BACKGROUND: Biology is complex and the effects of many interventions may vary between population groups. Subgroup analysis can give estimates for specific populations, but trials are usually too small for such analyses. PURPOSE: To test whether the effect of vitamin E on pneumonia risk is uniform over subgroups defined by smoking and exercise. METHODS: The Alpha-Tocopherol Beta-Carotene Cancer Prevention Study examined the effects of vitamin E (50 mg per day) and β-carotene (20 mg per day) on lung cancer in 29,133 male smokers aged 50-69 years using a 2 × 2 factorial design. The trial was conducted among the general community in Finland during 1985-1993; the intervention lasted for 6.0 years (median). In the present study, we tested the uniformity of vitamin E effect on the risk of hospital-treated pneumonia (898 cases) by adding a dummy variable to allow each subgroup its own vitamin E effect in a Cox model covering all participants. RESULTS: Vitamin E effect was not uniform over eight subgroups defined by baseline smoking (5-19 vs ≥20 cigarettes per day), age of smoking initiation (≤20 vs ≥21 years), and exercise during leisure time (yes vs no). Vitamin E decreased pneumonia risk by 69% (95% CI: 43% to 83%) among participants who had the least exposure to smoking and exercised during leisure time. Vitamin E increased pneumonia risk by 79% (95% CI: 27% to 150%) among those who had the highest exposure to smoking and did not exercise. LIMITATIONS: Although the evidence of heterogeneity is strong, it is not evident to what extent the estimates of effect or the limits between the subgroups can be extrapolated to other populations. CONCLUSION: Subgroup analysis of large trials should be encouraged, though caution is needed in the interpretation of findings. The role of vitamin E in susceptibility to pneumonia in physically active nonsmokers warrants further study. TRIAL REGISTRATION: NCT00342992.
  • Liu, Miao (Helsingfors universitet, 2017)
    The literature review covers different aspects of lipid oxidation and protein oxidation in meat.The mechanism of lipid and protein oxidation, factors influencing lipid oxidation, the consequences of protein oxidation, measurement methods, and the interactions between lipid oxidation, protein oxidation and meat color are introduced. The present thesis was aiming to study the effects of different fatty acid composition on lipid oxidation, protein oxidation and meat color in minced pork stored in modified atmosphere packages (80% O2, 20% CO2) at 5 oC during 12 days of storage. The possible interactions between lipid oxidation, protein oxidation and meat color were also investigated. Minced meat differing in fatty acid composition was prepared by mixing lean minced meat and fat fractions obtained by dry fractionation. Three groups of minced meat were obtained, namely, more saturated, medium saturated and less saturated. Lipid and protein oxidation were measured by determining thiobarbituric acid-reactive substances (TBARS) and free thiol content, respectively. Meat color measurement was performed using the Hunter L*, a*, b* system. The results showed that the less saturated group had higher oxidative stability in relation to lipid and protein oxidation than the more saturated and medium saturated groups, which might result from the balance between the proportion of unsaturated fatty acids and the vitamin E content. This was supported by the finding that the less saturated samples contained more unsaturated fatty acids and vitamin E than those in the more saturated and medium saturated groups. TBARS level was negatively related to free thiol content, indicating the presence of possible interactions between lipid and protein oxidation. Furthermore, a* values were found to be correlated to lipid and protein oxidation, suggesting likely interactions between these factors. However, color values were not influenced by fatty acid composition.
  • Hemilä, Harri Olavi; Rezaei, Yousef (2017)
    McCullough et al. (1) reviewed the pathophysiology and treatment options for contrast-induced acute kidney injury (CI-AKI). They stated that no effective adjunctive pharmaceutical had been demonstrated that either prevented or treated CI-AKI. However, they also suggested that of the agents being investigated, statins were the most promising. We would like to point out that strong evidence has also emerged regarding the effect of vitamin E against CI-AKI, which was not mentioned in their review.
  • Rezaei, Yousef; Hemilä, Harri (2017)
    A recent meta-analysis by Su et al. compared 12 different prophylactic interventions against contrast medium–induced acute kidney injury (CIAKI). In their meta-analysis, Su et al. pooled different vitamins to a single group of “vitamins and analogues” but in so doing did not take into account that vitamin C is water soluble whereas vitamin E is fat soluble, and therefore their relative effects might be different... Su et al. had identified 3 randomized trials on vitamin E prophylaxis against CIAKI. We pooled the results of these 3 studies and calculated a pooled estimate of RR = 0.38 (95% CI 0.24-0.62), indicating that vitamin E significantly prevented CIAKI.