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An Internet news search for "antioxidants" produces a mind-boggling list of articles—from hundreds of television outlets, magazines, and newspapers—explaining research-supported health claims of preventive and/or therapeutic actions of antioxidant compounds.
"Press and media outlets often focus on studies providing sensational headlines that capture attention," says Marion Franz, MS, RD, CDE, "but it is often impossible to discern the type of study such findings originate from." Franz is a nutrition consultant and contributing author of nutritional guidelines from the American Diabetes Association (ADA).
Nearly three-quarters of Americans use television, more than half use magazines, and a third use newspapers as primary sources of food and nutrition information.1 On any given day, reports may surface on a variety of topics such as antioxidant-loaded cranberries,2 the development of chocolate-flavored breath mints to capitalize on touted benefits of antioxidants in dark chocolate,3 or the testing of an antioxidant-containing nutritional supplement to help frail elderly people fight influenza.4
Medical professionals have the important task of helping patients view media reports with skepticism. Epidemiological and animal studies or the smaller clinical trials "certainly do not prove benefit or harm in humans," says Franz, but "simply suggest a direction that larger clinical trials might take."
While physicians understand the ins and outs of nutritional research and the health benefits antioxidants confer by minimizing free radicals caused by oxygen exposure at the cellular level, patients often do not, notes Judith Wylie-Rosett, EdD, RD, professor of epidemiology and population health at Albert Einstein College of Medicine in Bronx, New York.
ANTIOXIDANTS FROM FOODS
Antioxidants provide multiple potential health benefits, including neutralizing free radicals and bolstering cellular antioxidant defenses that may contribute to cardiovascular health, immune function, neurological function, vision, and prostate and urinary tract health.5
Antioxidant compounds have been identified in many foods. Carotenoids include beta-carotene in carrots and some fruits; lutein and zeaxanthin can be found in dark green vegetables, corn, eggs, and citrus fruits; and lycopene is in tomatoes.5
Flavonoids include anthocyanidins in berries, cherries, and red grapes; proanthocyanidins in cranberries, apples, strawberries, grapes, wine, peanuts, and cinnamon; flavanols such as catechins, epicatechins, and procyanidins in tea, chocolate, apples, and grapes; flavonols in onions, apples, tea, and broccoli; and flavanones in citrus fruits.5
Other antioxidants include isothiocyanates in cauliflower, broccoli, kale, and horseradish and the phenols caffeic acid and ferulic acid found in apples, pears, citrus fruits, and some vegetables.5
Antioxidant benefits are also derived from vitamin A in liver, dairy products, and fish; vitamin C in peppers and citrus fruits; vitamin E in fish oils, cereals, sunflower seeds, and nuts; and selenium in nuts and other plant foods, meats, and tuna.5
WHAT ABOUT SUPPLEMENTS?
Consuming a balanced diet is the optimal way to obtain antioxidants, but as a society we seem to be "trying to find the quick fix in terms of the one food, or the extract of that food, or the pill that was derived from whatever nutrient was in that food," says Wylie-Rosett.
Isolating antioxidant compounds into nutritional supplements plays to this mindset. However, using nutrient supplementation to mimic the nutritional effects of foods does not appear to be as effective as simply ingesting foods.6
"Supplements focus on suspected benefits from individual nutrients, when the benefits of a particular food may come not just from an individual nutrient but from a combination of nutrients in the food," Franz says.
ADA reports no clear evidence of benefit from vitamin or mineral supplementation in people with diabetes without underlying deficiencies; routine supplementation with antioxidants is not advised because of lack of evidence of efficacy and concern related to long-term safety.7
The American Heart Association (AHA) recommends avoiding antioxidant supplements and rather suggests a variety of fruits, vegetables, whole grains, and vegetable oils as the preferred source of these compounds.8
Specific medical conditions call for dietary supplements, says Wylie-Rosett, but "ideally such patients will be under the care of a registered dietitian as well as a physician."
Unfortunately, says American Dietetic Association spokesperson Roberta Anding, MS, RD, LD, CDE, many people don't use registered dietitians or physicians as health care partners. They purchase and take a nutritional supplement based on numbers they don't necessarily understand, potentially ingesting significantly more of a compound than they need.
Additionally, "people using supplements may miss the opportunity to consume plant-based foods," Wylie-Rosett notes, losing any potential benefits derived from both identified and unidentified antioxidants and other nutrients.
EMBRACE A WHOLE-FOODS APPROACH
"Taking supplements will never, ever substitute for quality eating," Anding says. "We need to embrace a whole-foods approach."
The health benefits from foods may not be what science currently explains, but what science is now uncovering or has yet to discover, notes Anding. Research once suggested that vitamins were the major antioxidants and disease-fighting chemicals in foods, but more recent findings indicate that may not be so. We previously thought of berries simply as good sources of vitamin C, but we now understand that the antioxidant benefits of these fruits come from polyphenolic compounds associated with their rich, dark color. And, she adds, research also has identified antioxidant compounds in whole grains, foods we once thought beneficial only as sources of fiber.
In keeping with the whole-foods approach, Anding reminds that "fresh is best, frozen second, canned third."
Eat a variety of foods as close to their natural state as possible, she says, even those that aren't known to offer superior health benefits, since "these may be the nutritional heroes of future research."
Anding also suggests imagining dining plates with an invisible line down the middle, keeping in mind that "half belongs to the fruit and vegetable world, a fourth belongs to whole grains, and a fourth belongs to protein."
"People often have a negative attitude about nutrition because
recommendations appear to change with time," Franz says, but one ongoing
recommendation is that eating food is "the best way to obtain all the
nutrients and substances needed by our bodies." 
Footnotes
The ADA Web site, www.diabetes.org/home.jsp, includes a Rate Your Plate activity, a diabetes-specific food pyramid, and diabetes meal plans.
The AHA Web site, www.americanheart.org, features a Healthy Lifestyles section offering diet and nutrition information.
A new book on the way from ADA, Complementary and Alternative Medicine (CAM) Supplement Use in People With Diabetes by Laura Shane-McWhorter, PharmD, BCPS, FASCP, BC-ADM, CDE, offers health care professionals detailed information about common supplements, including proposed mechanisms of action, clinical trial results, and possible drug interactions. The book will be available at http://store.diabetes.org June 1, 2007.
References
2. Krumm S: Tasty cranberries add antioxidants to diet. Lawrence Journal-World, December20 , 2006.
3. Schmeltzer J: Wrigley takes dip in chocolate. Chicago Tribune, December 16, 2006.
4. Reuters Health: Nutrients may help older people fight flu. Available online at today. reuters.com/news/articlenews.aspx?type=healthNews&storyID=2006-12-19T162622Z_01_COL958878_RTRUKOC_0_US-NUTRIENTSFLU.xml&WTmodLoc=HealthNewsHome_C2_healthNews-4. Accessed January 16, 2007.
5. International Food Information Council: Functional foods fact sheet: Antioxidants. Available online at www.ific.org/publications/factsheets/antioxidantfs.cfm. Accessed January 16, 2007.
6. Lichtenstein AH, Russell RM: Essential nutrients: Food or
supplements? JAMA 294:351–358, 2005.
7. American Diabetes Association: Nutrition recommendations and
interventions for diabetes—2006 (Position Statement).
Diabetes Care 29:2140–2157, 2006.
8. Lichtenstein AH, Appel LJ, Brands M, et al.: Diet and lifestyle recommendations revision 2006: A scientific statement from the American Heart Association Nutrition Committee. Circulation 114: 82–96, 2006.
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