Tip: Dietary supplements not so great
Scientific research continues to reinforce the link between good health and antioxidants, those biological compounds that help the body fight harmful effects caused by aging, diseases and environmental pollution. At every supermarket, big-box retailer and health-food store, the shelves are filled with dietary supplements extolling their antioxidant qualities. Which one should you buy?
The answer may be none of them, because new studies indicate health benefits of antioxidants come exclusively from eating a wide variety of food, not from concentrated extracts found in a pill or a capsule.
"There are several thousand biological compounds in fruits and vegetables," says Dr. Rui Hai Liu, a professor of food science at Cornell University. "It is impossible to use dietary supplements to meet these natural combinations." Liu, whose research specializes in the relationship between food and chronic diseases, says once plant compounds are "isolated" into a pure form and put into supplements, they may not be the same chemically as they are in the original food.
Another problem is toxicity. Several recent studies concluded that some nutritional supplements not only do no good, they may cause harm. "The pure compound in dietary supplement form reaches high concentrations [in the body] in a very short time," Liu says. "I would say keep away from the dietary supplements unless recommended by your family doctor." He notes there are cases in which vitamin and mineral supplements are warranted and necessary for people with certain chronic conditions or diseases such as cancer.
Among Liu's findings for specific foods is that fresh apples, especially the skins, inhibit breast cancer tumors. But it's not just fresh foods that have health benefits. Liu found that antioxidant qualities in tomatoes and corn are boosted when they are cooked.
Though there is no magic bullet, there may be a magic bushel. Because each food brings its exclusive chemical compounds to the table, for optimum nutrition, a wide variety of fruits, vegetables, legumes and whole grains should be eaten daily, Liu says. "You won't get the same health benefits if you eat just one or two fruits or vegetables."
Even the lowly, pungent yellow onion may be a disease fighter. Liu's research found it is protective against colon cancer and has healthful compounds not found anyplace else. "You won't get them from other fruits and vegetables," he says. Your friends may be repelled by the odor after you eat them, "but it's good to your health."
