Controversy over antioxidant supplements
response to the American Heart Association's (AHA) conclusion that
consumers should get their antioxidants from food rather than
dietary supplements.
"There is little reason to advise that individuals take antioxidant supplements to reduce their risk of cardiovascular disease," said Penny Kris-Etherton, distinguished professor of nutrition in the department of nutritional sciences at Pennsylvania State University, and head of the panel which reviewed recent research for the AHA.
Kris-Etherton claimed that research conducted on antioxidants between 1994 and 2002 showed that antioxidant supplements largely have no effect on preventing or treating cardiovascular disease. She urged consumers to follow the AHA's recommended diet, rich in fruits, vegetables, whole grains, fish, legumes, poultry and lean meats, to derive antioxidant vitamin benefits.
The president of the CRN, Annette Dickinson, agreed that more research needed to be carried out, but accused the AHA of trying to halt the initiation of any further investigations into the work of supplements.
"Antioxidants have been shown in some studies to enhance overall immune function, protect the eyes from cataracts and macular degeneration, slow the progression of Alzheimer's disease, and reduce the risk of some cancers," she said. "While many of the studies on vitamin E and heart disease have been disappointing, some have been positive. The AHA seems to be trying to prematurely close the door on supplement use, even while more studies continue."
The AHA also advocated that further research be carried out into the work of antioxidants from food sources.
"The role oxidative stress plays in the development and progression of heart disease has yet to be clarified," Kris-Etherton said. "We still know too little about the oxidative mechanisms in humans and lack biochemical markers with which to evaluate antioxidants."
The AHA's conclusions are published in this month's editon of Circulation: Journal of the American Heart Association.
A study published in June in the Journal of Agricultural of Food Chemistry suggested that artichokes and red kidney beans are among the best sources of dietary antioxidants. And, in addition to confirming the well-publicized high antioxidant ranking of such foods as cranberries and blueberries, the researchers found that Russet potatoes, pecans and even cinnamon are all excellent, although lesser-known, sources of antioxidants, which are thought to fight cancer, heart disease and Alzheimer's.
There are currently no government guidelines for consumers on how many antioxidants to consume and what kind of antioxidants to consume in their daily diet, as is the case with vitamins and minerals. A major barrier to such guidelines is a lack of consensus among nutrition researchers on uniform antioxidant measurements.
Scientists met in Orlando in June to try and rectify this problem and publication of preliminary recommendations from the meeting has been tentatively scheduled for September.
