Background: Oxidative damage is related to the development of several diseases. An improved antioxidant defence may therefore protect against these diseases. Recent studies have demonstrated that dietary plants contain several hundred different antioxidants.
Materials and methods: We have systematically assessed the total amount of antioxidants in a variety of dietary plants by the "ferric-reducing ability of plasma" assay, a method that measures the sum total of all antioxidants above a reference redox potential.
Results: Our results demonstrate that antioxidant levels vary considerably. Plants with the highest values include dog rose, sour cherry, blackberry, crowberry, blueberry, walnuts, sunflower seed, pomegranate and ginger. Among the dried culinary herbs tested, we found very high levels of antioxidants in oregano, sage, peppermint, garden thyme, lemon balm, clove, allspice and cinnamon.
Interpretation: Our results are in accordance with studies in experimental animals demonstrating beneficial effect against age-related neurodegeneration, carcinogenesis and atherosclerosis after treatment with some of the most antioxidant-rich foods identified in the present study.