Bioflavonoids (also called flavonoids) are a class of phytochemicals that are potent antioxidants, which scavenge many potentially damaging free radicals.  Free radicals are unstable chemicals formed in the body during metabolism and from exposure to environmental sources, such as pollution and cigarette smoke.  Free radicals are produced during energy metabolism and are necessary for immune function, but when an excessive number of free radicals are formed, they can attack healthy cells, especially their membrane lipids and proteins.  This, in turn, is thought to contribute to a degradation of the structure and function of these cellular components.Another aspect of the antioxidant properties of bioflavonoids is their synergy with vitamin C.  The bitter tasting flavanones hesperidin and naringin, from the white albedo layer of citrus peels, have been shown to extend the nutritional functions of vitamin C.

Bioflavonoids are also capable of binding to metal ions, which prevents these metals from acting as catalysts in the body to enhance free radical production. Many bioflavonoids, especially rutin and quercetin, support the health of the body’s circulatory system by helping maintain capillary blood flow and proper vascular permeability, integrity, and resiliency. Bioflavonoids are also involved in a wide array of other biochemical functions, such as immune function, platelet aggregation, enzyme activity, and the metabolism of collagen, cholesterol, and histamine.