Content of redox-active compounds (ie, antioxidants) in foods consumed in the United States

Abstract

Background: Supplements containing ascorbic acid, α-tocopherol, or β-carotene do not protect against oxidative stress-related diseases in most randomized intervention trials. We suggest that other redoxactive phytochemicals may be more effective and that a combination of different redox-active compounds (ie, antioxidants or reductants) may be needed for proper protection against oxidative damage. Objective: W eaimed to generate a ranked food table with values for total content of redox-active compounds to test this alternative antioxidant hypothesis. Design: An assay that measures the total concentration of redoxactive compounds above a certain cutoff reduction potential was used to analyze 1113 food samples obtained from the US Department of Agriculture National Food and Nutrient Analysis Program. Results: Large variations in the content of antioxidants were observed in different foods and food categories. The food groups spices and herbs, nuts and seeds, berries, and fruit and vegetables all contained foods with very high antioxidant contents. Most food categories also contained products almost devoid of antioxidants. Of the 50 food products highest in antioxidant concentrations, 13 were spices, 8 were in the fruit and vegetables category, 5 were berries, 5 were chocolate-based, 5 were breakfast cereals, and 4 were nuts or seeds. On the basis of typical serving sizes, blackberries, walnuts, strawberries, artichokes, cranberries, brewed coffee, raspberries, pecans, blueberries, ground cloves, grape juice, and unsweetened baking chocolate were at the top of the ranked list. Conclusion: This ranked antioxidant food table provides a useful tool for investigations into the possible health benefit of dietary antioxidants. © 2006 American Society for Nutrition.