CRN, NPA: Vitamin E and Cancer Study Doesn’t Reflect Scope of Research

The publication of a vitamin E and cancer study in the Journal of the American Medical Association has industry urging the public to consider the total scope of vitamin E-cancer research.

In the new study, researchers from a number of academic and health institutions reexamined data from the Selenium and Vitamin E Cancer Prevention Trial (SELECT), a 2008 study which found, among other conclusions, that vitamin E and selenium supplementation did not reduce prostate cancer risk in a trial of more than 34,000 men. Vitamin E supplementation was even linked to slightly more prostate cancer cases than placebo.

The most recent analysis of SELECT includes more follow-up (over 54,000 more human years) and more cases of prostate cancer (521) for the pool of over 35,000 SELECT participants. Compared to placebo, the new data shows a mean prostate cancer increase of 1.6 in men who supplemented with vitamin E.

But industry groups are urging the public to consider historical analysis of vitamin E and cancer, which on several occasions has demonstrated no risk and even risk reduction.

“Even taking the results of this SELECT research at face value, although ‘statistically significant’ to a statistician, one wonders if an absolute increase in the risk of prostate cancer of 1.6 cases per 1,000 person-years is really a ‘significantly increased risk of prostate cancer’ as noted in the article,” said Council for Responsible Nutrition (Washington, DC) vice president of scientific and regulatory affairs Duffy MacKay, ND.

MacKay further added that a severe limitation of the study was the lack of reporting plasma concentrations and dietary intakes of vitamin E and selenium in participants.

“This particular study does reveal the need for additional research into the link of vitamin E and prostate cancer…” said Natural products Association vice president of scientific and regulatory affairs Cara Welch, PhD. “What is important to remember is that the results of this study, specifically looking at vitamin E in isolation, cannot be extended to taking vitamin E in a combination supplement as the authors imply,” she added.