Quercetin is one of the types of plant pigments called flavonoids that are largely responsible for the colors of many fruits, flowers, and vegetables. It provides many health-promoting benefits. It acts as antihistamine (useful in reducing allergy symptoms) and helps reduce inflammation associated with various forms of arthritis. It also works as an antioxidant by scavenging damaging particles in the body known as free radicals. These particles occur naturally in the body but can damage cell membranes, interact with genetic material, and possibly contribute to the aging process as well as the development of a number of conditions including heart disease and cancer. Antioxidants such as Quercetin can neutralize free radicals and may reduce or even help prevent some of the damage they cause. Quercetin may have antioxidant, anti-inflammatory, antivral, immunomodulatory, anticancer and gastroprotective activities. It may also have anti-allergy activity and activity in preventing secondary complications of diabetes. It has been claimed that Quercetin protects against heart attacks and stroke, but recent research found no support for this claim. It may, however, have benefit in some allergies, in conditions characterized by capillary fragility, in chronic prostatis and in some cancers. It may have beneficial effects on immunity and may have gastro-protective effects. It may also protect against the development of such diabetic complications as cataracts, retinopathy, neuropathy and nephropathy.
Quercetin inhibits the production and release of histamine and other allergic/inflammatory substances. By acting as antioxidant, Quercetin appears to protect against the damage caused by LDL ("bad") cholesterol and may help prevent death from heart disease. Some studies suggest that Quercetin improves pain and other symptoms in men with chronic prostatitis (inflammation of the prostate). The dietery source of Quercetin include fruits and vegetables -- particularly citrus fruits, apples, onions, parsley, tea, and red wine. Olive oil, grapes, dark cherries, and dark berries, such as blueberries, blackberries, and bilberries are also high in flavonoids including Quercetin.
References:
University of Maryland Medical Center. http://www.umm.edu/altmed/articles/quercetin-000322.htm
PDR Health. http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/que_0219.shtml
