Resveratrol seems to be everywhere in the news these days. But another plant-based chemical, quercetin, is beginning to attract attention from researchers as well. Recent studies suggest that resveratrol and quercetin might actually be more effective when taken together.
Both resveratrol and quercetin are polyphenols, a group of antioxidant chemicals found in many fruits and vegetables. An antioxidan is a compound that destroys free radicals in the body, those atoms with unpaired electrons that cause damage to tissues and cells as they roam the body scavenging electrons from other atoms. The polyphenols have been found to have such health benefits as lowering LDL (bad) cholesterol in the body, and reducing the risk of heart disease and cancer. In fact, many scientists believe that the polyphenols may be some of our most powerful natural agents for the prevention of chronic diseases of aging, and even for slowing the aging process. Resveratrol is found in the skins and seeds of red and purple grapes, and in dark-colored berries and peanuts; good sources of quercetin are onions, especially red onions, and the skins of apples. Significant quantities of both quercetin and resveratrol are present in red wine. Although both resveratrol and quercetin are polyphenols, of the two, only quercetin is classed as a flavonoid. These plant pigments provide color in fruits, vegetables, and flowers and wine as well.
Some recent research has suggested that quercetin boosts resveratrol. Impressive as the effects of resveratrol may be alone, they may be enhanced by working together with quercetin. For example, in a 2008 in vitro (test tube) study (Yang et al.), researchers investigated the effects of various combinations of quercetin and resveratrol on adipogenesis and apoptosis. Adipogenesis is the formation of fat cells, or adipocytes; and apoptosis is the process of programmed cell death, by which the body rids itself of old, unhealthy, or excess cells. When maturing fat cells were treated with resveratrol and quercetin separately, resveratrol suppressed fat accumulation by 9%, while quercetin suppressed it by 15%. However, when given in combination, fat accumulation in the cells was decreased by more than 68%.
In addition, resveratrol and quercetin, administered individually, induced programmed cell death in mature fat cells by 18% and 15%, respectively. Given together, they increased apoptosis in mature adipocytes more than the single compounds did. These data may have significant implications for the development of products using resveratrol and quercetin for weight loss. The researchers stated, Taken together, our data indicate that combinations of resveratrol and quercetin can exert potential anti-obesity effects by inhibiting differentiation of preadipocytes and inducing apoptosis of mature adipocytes.
Some research scientists believe that the combination of resveratrol and quercetin may not be the only synergistic possibility. It may be that a group of five compounds can work together in synergy to offer protection against heart disease and cancer. Resveratrol and quercetin, vitamin E, vitamin C, and selenium (a trace mineral) are being investigated together with this goal in mind.