The term antioxidant refers to a group of organic substances found in plants that can reduce the damage made to cell walls by "free radicals," molecules made in the environment by substances such as oxygen and carbon dioxide. By reducing this cell damage, antioxidants can be a health benefit by preventing cancer, heart disease and other chronic illnesses. Antioxidants include:
- certain vitamins, such as vitamin A, C and E
- minerals, such as selenium
- plant pigments, such as carotenoids.
Who Takes Antioxidant Supplements?
Many manufacturers are now offering antioxidants as dietary supplements, and Americans are biting. A recent survey from the American Institute for Cancer Research (AICR), for example, found that as Americans grow older, they are much less likely to make dietary changes that can lower cancer risk but instead turn to dietary supplements. In the study, 43% of Americans state they take a multivitamin daily for cancer protection and 21% take some other type of dietary supplement to lower their risk. Thirty-nine percent of responders have made changes to their diet to prevent cancer.
Are Supplements as Good as Real Food?
Although there is much research on antioxidant compounds that show health benefits, most of the studies have involved diet changes such as increasing fruits, vegetables and whole grains, not dietary supplements. In fact, there have been some studies, for beta-carotene for example, that found that dietary supplements have been linked to an increased risk cancer risk, particularly lung cancer.
Fruits and vegetables contain more healthful substances than single doses of antioxidants. In fact, scientists stress that there continue to be new discoveries on beneficial compounds in produce that have not previously been known, and therefore are not included in antioxidant dietary supplements. Garlic, for example, provides beneficial antioxidants, but supplements are missing important compounds found in the plant that convert the compound into its active form. Another recent study, conducted by the Institute of Food Research in England, found that fruit actually contains more beneficial antioxidants than they previously thought. The study was conducted on apples, peaches and nectarines, and the researchers found that these fruits contained up to five times more antioxidant compounds, called polyphenols, than had been estimated from prior studies.
In addition, fruits and vegetables contain energy and fiber, neither of which is included in a nutritional pill or powder. Fiber is important for the digestive system, in reducing cholesterol levels, and may have benefit in the reduction of colon cancer. Energy, of course, is needed to fuel the cells for daily activity and to repair body tissue damaged from daily use.
What Do the Experts Say?
The American Heart Association is one group that does not recommend using antioxidant supplements until more data is available on its benefits and safety. They continue to recommend dietary changes such as including more fruits and vegetables in the diet, and to lower fat, cholesterol and sugar by using lean meats, whole grains and monounsaturated fats from beans, nuts and seeds.
When Are Supplements Beneficial?
There is a certain population for whom supplements are useful:
- the elderly
- those with a reduced food intake
- heavy drinkers
- frequent aspirin users
- people with chronic immune deficiency diseases
However, most of these individuals would benefit more from a multivitamin rather than specific antioxidant supplements. Multivitamins contain the recommended daily allowance for many of the substances that the body uses to produce its own natural antioxidant compounds.