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Quercetin

Description

Quercetin is a bioflavonoid, a water-soluble plant pigment that provides the color and many health benefits to plants and fruits. Quercetin is the backbone for many other flavonoids. Quercetin, called, "the most important flavonoid" by Nutrition in Cancer, is a powerful antioxidant which has demonstrated anticarcinogenic properties (Nutr. Cancer 1993, 20:21-9). Being a potent bioflavonoid, quercetin is used in inflammatory and allergic problems. It is effective because it stabilizes cell membranes, decreases the release of inflammation mediators, and decreases the contraction of smooth muscle (Murray M. Enc of Nat Med. Prima Publ., Rocklin, Ca. 1991. p.298). Quercetin may help prevent immune cells from releasing histamine, a chemical substance that initiates the sneezing, itching and swelling of an allergic reaction. Quercetin regulates the permeability of the capillaries and prevents the rupture of the capillaries that causes bruising. Quercetin is also known as an antiviral. Bioflavonoids have demonstrated a positive, protective effect on human viruses (J. Med. Virol. 15:71-79). Quercetin is found in red wine, onions, apples, grapefruit, black tea and in smaller amounts in green, leafy vegetables.

Signs and Symptoms for Nutrient Applications

Clinical applications include the following: - Highly potent antioxidant - Inflammatory conditions - Asthma - Diabetes - Diabetic retinopathies - Cataracts - Viral infections - Common cold

Clinical Applications/Research

Asthma

Quercetin inhibits both the synthesis and release of histamine, and other allergic substances, plus it has a sparing effect on vitamin C (Biochem Pharmacol 1983;32:1141-1148; J Allergy Clin Immunol 1984;73:801-809).

Diabetes

Quercetin enhances insulin secretion, protects the pancreatic beta cells from free radicals, and inhibits platelet aggregation (clumping together) (Biochem Pharmacol 1983;32:1141-1148). It can also decrease the accumulation of sorbitol, a sugar, in the eye, which can delay the onset of cataracts (Science 1977;195:87-89).

Antivital Action

Although most of the scientific evidence for quercetin’s antiviral activity is in vitro and in animals, it has shown to be effective against the herpes virus, influenza virus, polio virus, and respiratory virus, inhibiting both viral replication and infection (Beladi I et al. In vitro and in vivo antiviral effects of flavonoids. In: Flavonoids and Bioflavonoids. Farkas L et al. Eds. Elsevier NY, NY. 1982, pp. 443-450).

Anticarcinogenic

Again, the human studies are lacking, but the in vitro and animal studies are highly impressive. Significant antitumor activity has been demonstrated against a wide range of tumors, including breast, ovarian, colon, brain, and leukemia (J Clin Biochem Nutr 1994;17:153-160; Clin Biochem 1994;27:245-248).

Suggested Dosage

250 mg three times daily or as directed by your healthcare professional.

Disclaimer: The statements above have not been evaluated by the FDA. The nutritional suggestions and research provided are for informational purposes only and are not intended to diagnose, treat, cure or prevent disease and should not be used as a substitute for sound medical advice. Please see your health care professional in all matters pertaining to your physical health.

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