ORAC is an acronym that stands for oxygen radical absorbance capacity. This laboratory test was developed by USDA researchers at Tufts University to rate the antioxidant levels of fruits and vegetables.
ORAC measures the degree to which a sample inhibits the action of an oxidizing agent and how long it takes to do so. Then, it integrates the two measurements into a single value. ORAC provides an accurate and reproducible measurement for different types of antioxidants having different strengths.
Natural fruits typically score between 500 and 900 ORAC units per 100 grams. The Food and Drug Administration (FDA) recently suggested that Americans increase their consumption of antioxidants to 7000 ORAC units daily — 5 to 10 servings daily of colorful fruits and vegetables.
Based on this laboratory test, the top 20 antioxidant-rich foods are listed here. Controversy exists over the importance of antioxidant supplementation in patients with cancer. However, one study of children with acute lymphoblastic leukemia reported that total antioxidant capacity as measured by ORAC was inversely associated with treatment-related toxicity.
John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.