A review of research carried out by Danish scientists questioning the effectiveness of a range of antioxidants — and even suggesting vitamins A, E, and beta-carotene may increase mortality rates — excited mainstream media while exasperating the supplements industry.
Major news outlets all over the world including the BBC, Asian news outlets and many American newspapers ran with predictable headlines such as "Antioxidants don't work" or even more sensationally: "Antioxidants can kill you," while the industry stepped in en masse to defend antioxidants against what it describes as the review's inappropriate terms. A meta-study published in 2004 on vitamin E provoked a similar slew of sensational headlines and industry response.
The new research, published in the Feb. 28 Journal of the American Medical Association, concluded: "We did not find convincing evidence that antioxidant supplements have beneficial effects on mortality. Even more, beta carotene, vitamin A, and vitamin E seem to increase the risk of death. Further randomised trials are needed to establish the effects of vitamin C and selenium."
The industry's criticism revolves around the fact the review included many studies where already diseased subjects were the focus — an area where antioxidant consumption has demonstrated little effect. Criticising antioxidants for failing to cure disease was preposterous, the industry said.
"How sensible scientists can suggest that a modest intervention of a single antioxidant supplement (which is readily available in food), can have a major effect in reversing life-threatening pathology, where patients already have advanced cardiovascular disease, is ridiculous," said Dr Ann Walker of the UK-based Health Supplements Information Service. "Such an intervention would be a 'drop in the ocean' against such severe conditions. In my view, the results of these mixed-sample meta-analyses are worthless."
The Washington DC-based Council for Responsible Nutrition (CRN) said the review was like "comparing apples and oranges." CRN's scientific and regulatory affairs vice president, Andrew Shao, noted: "It was only after the researchers divided the chosen clinical trials into 'high risk bias' and 'low risk bias' groups, using their own criteria, that they observed a statistically significant effect on mortality. This meta-analysis appears to be a predetermined conclusion in search of a method to support it."
According to the US National Poisoning and Exposure Database, there were no deaths from vitamin consumption in 2005.