A. Alice H. Lichtenstein, DSc, director of the Cardiovascular Nutrition Laboratory at the Human Nutrition Research Center on Aging and executive editor of this newsletter, answers: “Antioxidants neutralize free radicals, molecules in need of an electron which roam the body potentially causing damage by taking electrons from other molecules. Many detrimental effects of aging and causes of disease have been attributed to this oxidative damage. The body makes its own antioxidants, but there are compounds with antioxidant properties in plant foods.
“Some phytochemicals have antioxidant properties, but the bulk of the research on antioxidants has been on vitamins with antioxidant properties, namely vitamin C, vitamin E, and beta-carotene, a precursor to vitamin A. If you put LDL particles with low and high levels of vitamin E in a test tube and add a pro-oxidant into the system, the LDL with high levels of vitamin E will be more resistant to oxidation. But, unfortunately, it doesn’t appear to work quite that way in our bodies. Studies have found just taking vitamin E, vitamin D, or beta-carotene supplements did not result in any measurable benefit, and in some cases high doses of antioxidant vitamins were associated with adverse effects.
“High levels of supplemental beta-carotene, for example, actually increased risk for lung cancer in vulnerable individuals such as smokers. Very high intake of supplemental vitamin A has been associated with elevated risk for bone fracture in older women.
“Beyond supplements, eating vitamin- and phytochemical-rich plant foods is important for many reasons. Eating more fruits, vegetables, nuts, seeds, legumes, and whole grains in place of sugary, salty, and refined carbohydrate foods and processed meats leads to a healthy dietary pattern and positive health outcomes. Foods that are naturally high in vitamins, minerals, and phytochemicals also tend to be rich in fiber and unsaturated fats, low in saturated fat and refined carbohydrates, and have little added sugars and salt. That’s why it’s important to focus on overall dietary pattern, not individual foods, nutrients, or phytochemicals.”