By Stephen DANIELLS 24-Sep-2015
Specific sub-populations may benefit from antioxidant intakes to support healthy aging, with men particularly seen as an ‘at-risk’ group, says a new paper published in the American Journal of Epidemiology.
Data from the Supplementation with Antioxidant Vitamins and Minerals (SU.VI.MAX) Study (1994-2002) indicated that antioxidant supplements were associated with a “greater healthy aging probability” among men, but not women. The double-blind, placebo-controlled SU.VI.MAX study involved long term supplementation with vitamin C (120 mg), beta-carotene (6 mg), vitamin E (30 mg), selenium (100 ug), and zinc (20 mg).
“To the best of our knowledge, our study is the first to investigate the relationship between antioxidant supplements and a multidimensional measure of healthy aging,” wrote the researchers, led by Karen Assmann from the Université Paris 13 in France.
“Our stratified analyses indicate that, while an overall beneficial association of a supplementation with combined antioxidant vitamins and minerals at moderate doses may not exist, specific subpopulations could benefit from antioxidant treatment. Yet, our subgroup analyses were of exploratory nature and thus have to be interpreted with caution. To verify our findings, further randomized controlled trials targeting populations at risk with a low baseline antioxidant status would be needed. According to our data, men may be such an ‘at risk’ group.”
Oxidative stress and aging
While oxidative stress has been a focus for the underlying biological mechanisms of aging and declines in health as we age, intervention trials using dietary supplements have often yielded conflicting results.
The medical community and the mainstream media are often quick to cite a controversial meta-analyses by Bjelakovic et al. in the Journal of the American Medical Association (2007, Vol. 297, pp. 842-857) which concluded that vitamins A and E, and beta-carotene may increase mortality risk by up to 16%.
However, that data was re-analyzed by a team of internationally renowned antioxidant scientists in 2010 which arrived at a different set of conclusions. This re-analysis, published in Nutrients, found that 36% of the trials showed a positive outcome or that the antioxidant supplements were beneficial, 60% had a null outcome, while only 4% found negative outcome.
There are also several meta-analyses of RCTs that contrast with the work done by Bjelakovic et al., which found no effect on all-cause mortality for vitamin E supplements, including Berry et al (Clin Trials 2009, Vol. 6, pp. 28-41), Abner et al, (Curr Aging Sci 2011, Vol. 4, pp. 158-170), Curtis et al, (Cardiovasc Drugs Ther, 2014, Vol. 28, pp. 563-573), and Jiang et al (J Nutr Sci Vitaminol, 2014, Vol. 60, pp. 194-205).
It should also be noted that the 10-year PHS II RCT did not find any adverse outcomes for vitamin E (Wang et al., Am J Clin Nutr 2014, Vol. 100, pp. 915-23).
On the positive side, data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study published in 2012 also indicated that users of antioxidant vitamin supplements may be associated with a 48% reduction in the risk of cancer mortality and a 42% reduction in the risk of ‘all-cause mortality’ over 11 years of study (European Journal of Nutrition, Vol. 51, pp 407-413).
Data from the SU.VI.MAX study adds to the body of literature around this subject, finding that, for the whole study population of 3,966 participants with a mean age of 65.3, no significant benefits were observed.
No significant benefits were observed for women, either, said Assmann and her co-workers.
For men, however, antioxidant supplementation was associated with a higher probability of healthy aging, they said.
Other subgroups also exhibited beneficial effects from the supplements: In men and women with low vitamin C levels at the start of the study; in men with low zinc levels at the start of the study; and in men with low fruit and vegetable intakes at the start of the study (fewer than five portions per day).
“The effect of supplementation appeared to be stronger among women with low vitamin C concentrations than among men with low serum vitamin C,” they wrote. “Yet, as only few women had vitamin C concentrations below the 25th percentile, statistical power was low, and no significant results were observed. It is possible that the sex specificity of our findings is partly explained by sex differences in the prevalence of low baseline vitamin C concentrations in our sample; that is, if as many women as men in our sample would have had low vitamin C concentrations at baseline, there may have been a more pronounced overall effect of supplementation among women. However, there may be additional underlying factors.”
“Altogether, our results support the importance of a well-balanced intake of antioxidant nutrients at nutritional doses (as can be supplied by a diversified and adequate fruit and vegetable intake) for preserving overall health in the course of aging.”
Source: American Journal of Epidemiology
Published online ahead of print, doi: 10.1093/aje/kwv105
“Healthy Aging 5 Years After a Period of Daily Supplementation With Antioxidant Nutrients: A Post Hoc Analysis of the French Randomized Trial SU.VI.MAX”
Authors: K.E. Assmann, V.A. Andreeva, C. Jeandel, S. Hercberg, P. Galan, E. Kesse-Guyot