Vitamin and antioxidant supplements don"t help you live longer and may even cut your life short, according to a study in the April 16 issue of  the Cochrane Database of Systematic Reviews. The researchers contend that healthy people who take antioxidant supplements to prevent systemic diseases, such as cancer, could be adversely disrupting their body"s natural physiological defense mechanisms.

But, some optometrists say this study is deeply flawed.

In the retrospective study, a team of scientists in Denmark analyzed pooled data from 67 different studies that included 232,550 total participants. The subjects were randomized into an antioxidant supplement group (beta carotene, vitamin A, vitamin C, vitamin E and selenium), a placebo group or a "no intervention" group.

About 75% of participants were considered healthy at the beginning of the study, and the remaining individuals were diagnosed with various existing diseases, including gastrointestinal, neurological, ocular, renal and cardiovascular disorders.

The scientists found that vitamin A supplements increased the risk of death in healthy participants by 16%. Also, beta carotene was associated with a 7% increased risk for death, and vitamin E carried a 4% increased risk. The researchers found no association between vitamin C and a higher mortality risk.

But, several founding members of the Optometric Nutrition Society have taken issue with this study. "It appears to be a systematic attempt by the authors to publish work that supports their own predetermined conclusions about antioxidants and the way they should be regulated," says Research Committee Co-Chair Ellen Troyer, M.T., M.A.

Vice President George Schmidt, O.D., says that the authors "purposely excluded studies that showed no difference [in increased mortality risk] and made little effort to explain many of their conclusions."

Ms. Troyer criticized both the authors" methods and results. "The researchers identified 748 studies that could be included in the analysis. Of those, they excluded all but 67 studies. Thus, their conclusions are based on less than 9% of the totality of available randomized, controlled trial evidence on antioxidant supplementation."

Also, the researchers excluded 405 articles in which no deathes were reported, Ms. Troyer says. And, they didn"t eliminate deaths from causes that have nothing to do with supplementation.

Gluud L, Simonetti R, Gluud C, et al. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev 2008 Apr 16;(2):CD007176.