Thursday, May 01, 2008

When "recent studies" contradict conventional wisdom

A recent study has generated negative headlines worldwide and caused consumers to question the efficacy and safety of antioxidant supplements. Many health professionals and nutrition experts have been highly critical of this study, and they have been quick to respond with refuting analyses and firm rebuttals.

Earlier this month, an updated meta-analysis was published in the Cochrane Database of Systematic Reviews entitled Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Almost immediately, scores of headlines and articles appeared stating that antioxidant vitamins were not only useless, but that they also shorten life span.

The Cochrane study is not new research. Rather, it is a slightly adjusted version of a meta-analysis published in 2007 in the Journal of the American Medical Association. That JAMA study received very stern criticism at the time of its publishing for many of its methods and conclusions, and this newer version of the study hasn't been any better received.

But unfortunately, with the onslaught of sensationalist headlines and scare tactics it is often difficult for the average person to know what to believe, and even harder to know how to defend those beliefs. To make matters worse, health professionals and physicians are often just as susceptible to these scare tactics, and many seldom get past the headlines, making it even more difficult to discuss nutrition, diet, and preventive health in a reasonable manner.

What follows are links to analyses and rebuttals of the most recent Cochrane study. A greater understanding of this and similar studies should assist you in future discussions with your contacts and health professionals.

Council For Responsible Nutrition (CRN) comments and analysis.

Stephen Daniells, PhD, the science editor for and Dr. Daniells received a PhD in chemistry from Queen's University of Belfast.