• Quercetin Chalcone
Quercetin belongs to a class of water-soluble plant coloring substances called
Quercetin is not an essential nutrient. It is found in red wine, grapefruit, onions, apples, black tea, and, in lesser amounts, in leafy green vegetables and beans. However, to get a therapeutic dosage, you'll have to take a supplement.
Quercetin supplements are available in pill and tablet form.
A typical dosage is 200 to 400 mg 3 times daily. A special type of quercetin, quercetin chalcone, is claimed to be absorbed better, but there is little reliable evidence to prove this.
Quercetin is widely marketed as a treatment for allergic conditions such as
A different proposed use of quercetin does have some meaningful supporting evidence:
As noted above, it has been suggested that quercetin’s antioxidant properties might make it helpful for preventing
An animal study found that quercetin might protect rodents with
A one-month, double-blind, placebo-controlled trial of 30 men with chronic pelvic pain (
) tested the potential effectiveness of quercetin.
While these are promising results, the study was small and cannot be regarded as definitive. Furthermore, researchers failed to provide the usual statistical evaluation required for such studies (a statistical analysis that directly compares the results in the treatment group against those in the placebo group). Thus, further study will be necessary to discover whether quercetin is actually effective for prostatitis.
Quercetin appears to be quite safe. However, concerns have been raised that, under some circumstances, it might raise cancer risk. Quercetin "fails" a standard laboratory test called the Ames test, which is designed to identify chemicals that might be carcinogenic. Nonetheless, a bad showing on the Ames test does not definitely mean a chemical causes cancer. Most other evidence suggests that quercetin does not cause cancer and may, in fact, help prevent cancer. 19,20,21
Evidence suggests that use of quercetin supplements can elevate urine and blood levels of the substance homovanillic acid.
1. Ogasawara H, Middleton E Jr. Effect of selected flavonoids on histamine release (HR) and hydrogen peroxide (H2O2) generation by human leukocytes [abstract]. J Allergy Clin Immunol . 1985;75(suppl):184.
5. Rodriguez LV, Janzen N, Raz S, et al. Treatment of interstitial cystitis with a quercetin containing compound: a preliminary, double-blind placebo control trial. Presented at: American Urological Association 2001 Annual Meeting; June 2-7, 2001; Anaheim, CA.
7. Hayek T, Fuhrman B, Vaya J. Reduced progression of atherosclerosis in apolipoprotein E-deficient mice following consumption of red wine, or its polyphenols quercetin or catechin, is associated with reduced susceptibility of LDL to oxidation and aggregation. Arterioscler Thromb Vasc Biol . 1997;17:2744-2752.
Last reviewed April 2009 by EBSCO CAM Review Board
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