Boost your immune system. Slow down aging. Reverse heart disease. Antioxidants have emerged as a near-universal cure for what ails you, regardless of the ailment. What exactly are these busy body advocates -- and can they really live up to all the hype?
Antioxidants are the first line of attack and the body's best defense against the damage caused by free radicals, highly unstable molecules that wreak havoc in the body, causing damage to cells and DNA. Although they are formed during normal body processes like breathing and digestion, production of free radicals is accelerated during times of stress and illness. Exposure to the sun, alcohol and cigarette smoke also increases production. It's this regular assault on the body's cells that sets the stage for premature aging and chronic diseases like cancer, heart disease, Alzheimer's, arthritis and macular degeneration.
The most commonly known and studied antioxidants are vitamins A, C, E and selenium, but there are estimated to be more than 4,000 compounds in foods that provide protection. Besides vitamins and minerals, some enzymes and phytonutrients also function as antioxidants. Among them: lycopene (found in tomatoes and other red fruits); flavonoids (found in teas, chocolate and wine); and a variety of polyphenols (found in pomegranates, berries and herbs). While their potential benefits are lesser known, there's an increasing body of promising scientific evidence about these "other" antioxidants.
A study reported in the European Journal of Clinical Nutrition found a 20% reduction in risk of death from heart disease among participants who consumed the most dietary flavonoids (tea was the primary source). A more recent study by the University of California showed daily consumption of 8.5 ounces of pomegranate juice improved blood flow to the heart, suggesting "that pomegranate juice may have important clinical benefits in those with coronary heart disease. Also, it may help to prevent it," according to Dean Ornish, lead author of the study.
Currently, there are no government guidelines outlining the amount or type of antioxidants that Americans should consume each day, with the exception of antioxidant vitamins and minerals. This doesn't deter consumers, for whom supplements remain a popular way to ensure adequate intake. Some 62% of Americans claim to use dietary supplements, a third of whom take single antioxidant supplements like vitamin C, vitamin E or beta-carotene (a form of vitamin A). The high percentage may be due in part to two recently approved health claims for dietary supplements by the Food and Drug Administration. The government agency concluded that evidence linking adequate intake of vitamins C and E -- as well as selenium -- with reduced cancer risk is strong enough that supplement manufacturers can now make these claims on their labels.
Earlier this month, a qualified health claim for tomato products containing lycopene was issued by the FDA, which agreed that some research submitted with the application showed lycopene's potential role in preventing prostate cancer.
Health claims associating antioxidant-rich foods with reduced risk of disease is an appealing idea for many manufacturers, who tout the benefits on packaging and in marketing efforts.
"As long as the romance copy in labeling and advertising is informational, it is allowable on a food label," said Robert Earl, senior director of nutrition policy at the National Food Products Association.
Scientists and dietitians agree that the best way to get an adequate variety of antioxidants is by "eating a variety of foods, emphasizing fruits and vegetables of all colors, as well as whole grains and legumes," said Allison Beadle, a registered dietitian and nutritionist for H-E-B Central Market, San Antonio. While taste is the ultimate test, health benefit information can influence consumer choice as they walk down the aisle, she added.
"Some customers might be swayed to purchase a product based upon that information one time, but the bottom line is that if it doesn't taste good, you can bet they won't buy it a second time," Beadle said. Along with whole health category products like Pom Wonderful and Odwalla juices, mainstream products like Lipton tea, V8 and Heinz ketchup are jumping on the antioxidant bandwagon too.
The largest, most comprehensive analysis of the antioxidant content of commonly consumed foods was released last year by the U.S. Department of Agriculture and confirmed what many prior studies have shown. "The bottom line is the same: eat more fruits and veggies," said Ronald Prior, a USDA chemist and nutritionist, and lead author of the report. "This study confirms that those foods are full of benefits, particularly those with higher levels of antioxidants. Nuts and spices are also good sources."
While the 2005 Dietary Guide-lines for Americans don't specifically recommend eating more antioxidants, there is a strong emphasis on increased consumption of fruits, vegetables and whole grains, all good sources of these potent, disease-fighting compounds. The American Institute for Cancer Research concurs, estimating that consumption of the recommended five servings of fruits and vegetables a day would lead to a 20% decrease in cancer rates, due in large part to their antioxidant content.
Many consumers are aware of the benefits and are seeking out products that are high in antioxidants, Beadle said. Retailers who follow these food trends closely will understand how manufacturers are putting science into product development and will be able to meet the needs of today's consumers.
"Consumer interest in nutrition in general and in specific food components continues to grow. Therefore, the ways in which food manufacturers can describe components of a given food [such as antioxidant content] helps consumers differentiate product A from product B and in making overall wise decisions for health," the NFPA's Earl said.
Note: Capacity totals were created for comparison between foods, and are not tied to any particular measurement.