And there's a third mystery: Is the disease-fighting capacity of fruits and vegetables directly attributable to antioxidants, or is it based on some other qualities or compounds in these foods?
Victoria Drake, a research associate at the Linus Pauling Institute at Oregon State University, put it this way in an e-mail: "Looking at the epidemiological data we have to date, we know . . . that diets rich in fruits and vegetables (antioxidant-rich foods) can reduce the risk of chronic diseases, such as cardiovascular diseases. But evidence that very high doses of individual micronutrients or phytochemicals can do the same is inconsistent and relatively weak. [As with food-based antioxidants], we would need well-controlled clinical trials to properly address the 'antioxidant hypothesis.' A healthy diet is key; supplements should be used only as 'nutritional insurance.' "
A study in the May 29 issue of the journal PLoS Genetics raises the intriguing question of whether our bodies might benefit from some exposure to free radicals.
TK: It doesn’t seem that antioxidants will be discredited anytime soon, and scientists may well add to the halo of antioxidants, phytochemicals and flavonoids with further research. Caution against an “antioxidant backlash” suggests that produce marketers should remember to put the “new” in nutrition by promoting old school vitamins, minerals and fiber.