Antioxidants: The Potency Debate
by Toni Tarver
Every day, consumers are inundated with messages extolling the benefits of antioxidants and their potential remarkable ability to clear harmful free radicals from the body. In fact, it is impossible to walk down the aisles of any supermarket without seeing a myriad of food products with labels announcing the level of antioxidants they contain. But many of those messages may be misleading as much of the information about the health benefits of antioxidants is exaggerated and, some say, downright deceptive.
In Session 253, “Antioxidants, Science, and Health: New Perspectives,” presenter John Finley of Louisiana State University discussed how the information about the properties and benefits of antioxidants has largely been exaggerated and misconstrued. He pointed out that processing profoundly affects the potency and bioavailability of antioxidants in various foods. Moreover, some antioxidants that show promise in laboratory studies have limited or no effectiveness within the human body, Finley said. Once antioxidants are ingested, many either lose their potency or are inadequately absorbed by cells. To illustrate his point, Finley referred to a recent study showing that anthocyanins from blueberries were helpful in protecting cells from inflammation but useless at treating cells that were already inflamed.
Presenter Navindra Seeram of the University of Rhode Island had a slightly different view of the efficacy of antioxidants within the body. Seeram and his colleagues believe that the body indeed absorbs antioxidants but that the mechanisms scientists use for detection and absorption are ineffective. He presented data indicating that after antioxidants are ingested, the body metabolizes them into other compounds that are either poorly studied or not documented at all in science. Presenter Darryl Sullivan of Covance Laboratories endorsed this perspective. Sullivan pointed out that more than 5,000 phytochemical compounds exist; most of them have not been identified. Research on antioxidants is in its infancy, he said, and scientists have a lot more to learn. In addition, he stressed that some of the current methods for studying and detecting antioxidants are good, but many more methods are needed.
Discussions on the processing of antioxidant-rich foods and the degree of antioxidant absorption in the body could soon be irrelevant. Presenter Li Li Ji of the University of Wisconsin presented compelling data on how exercise facilitates the body’s inherent ability to scavenge and get rid of free radicals. His research indicates that moderate exercise appears to have a deleterious effect on free radicals within the human body (rigorous exercise apparently has the opposite effect).
The debate on the healthfulness of antioxidants is sure to continue, but in the meantime, consumers should continue to eat fruits and vegetables (both rich in antioxidants) and engage in moderate physical activity just in case.