PORTLAND, Maine - USDA scientists recently concluded that eating Wild Blueberries and other antioxidant-rich foods at every meal helps prevent oxidative stress. (Journal of the American College of Nutrition, Vol. 26, No. 2, 170-181, 2007) This study advances antioxidant research by moving beyond the measurement of antioxidants in foods to actual examination of the performance of specific fruits against oxidative stress in the body. Oxidative stress is linked to chronic diseases and aging.
"We are confident that consumption of Wild Blueberries or other high antioxidant foods is going to be beneficial in fighting oxidative stress," said lead scientist Ronald L. Prior, Ph.D., USDA Arkansas Children's Nutrition Center. "It's not just what you eat but when you eat it that matters. Phytochemicals in foods have varying degrees of bioavailability and generally are cleared from the blood 2-4 hours after they're eaten. Ensuring that your body has a steady supply of antioxidant-rich foods can help combat oxidative stress throughout the day." The study also found that eating a meal with no antioxidants -- just carbohydrates, fat or protein -- lowers the antioxidant levels and causes oxidative stress. "You're deficit spending when you eat junk food. You need to continually consume antioxidant-rich foods to keep levels up for optimal health."
According to Dr. Prior, results from five separate clinical trials at four different institutions were combined in the analysis. During the trials, subjects ate Wild Blueberries, dried plums, cherries, grapes, kiwifruit, or strawberries. Affiliated research partners included the USDA Human Nutrition Research Center on Aging in Boston, Massachusetts, the USDA/ARS Western Human Nutrition Research Center at the University of California, Davis, and the Department of Food Science and Human Nutrition at the University of Maine. In addition to evaluating changes in antioxidant status, the studies resulted in preliminary recommendations for antioxidant intake. "It takes about 2.5 servings of antioxidant containing fruits and/or vegetables in a meal and a little less if you choose high antioxidant foods like Wild Blueberries to prevent oxidative stress following the meal. The more calories you take in the more dietary antioxidants you need," said Prior.
According to Wild Blueberry Association Nutrition Advisor Susan Davis, M.S., R.D., this research proves yet again the importance of fruits and vegetables and a diet that minimizes foods with little or no nutritional value. "Incorporate fruits and vegetables and other whole foods like grains and nuts into every meal to get the full phytochemical benefits you need to fight oxidative stress and inflammation," said Davis. "Fresh, frozen, canned, juice or dried, all forms count when you're trying to increase your intake of fruits and vegetables. When it comes to Wild Blueberries, eat at least 1/2 cup every day as part of a well-balanced diet."