Quercetin Health Benefits
Quercetin health benefits can be gotten from in many plants and foods, most notably red grapes, red wine, apples, tea, berries, and onions. For more than a decade, quercetin has been recognized as a potent antioxidant that has strong anti-inflammatory and anti-allergy effects. It inhibiting the production and release of histamine and other inflammatory factors.
Quercetin for BPH, Prostatitis and Prostate Cancer
Quercetin is also used to relieve symptoms for men with BPH, prostatitis and prostate cancer. It has been identified as being especially beneficial for BPH and in cases of prostatitis in numerous clinical studies, usually at a dose of 500 mg daily.
Chronic Nonbacterial Prostatitis/Chronic Pelvic Pain
In a randomized, double-blind study published in Urology, 28 men who had chronic nonbacterial prostatitis/chronic pelvic pain syndrome took either placebo or 500 mg of quercetin twice a day for one month. The authors also conducted a follow-up unblind, open-label study that involved an additional 17 men who received a supplement that contained quercetin, as well as saw palmetto, bromelain, cranberry, and papain.
At the end of the month, the International Prostate Symptom Score (IPSS) fell from 21.0 to 13.1 in the quercetin group and from 20.2 to 18.8 in the placebo group. An improvement in symptoms of at least 25 percent was reported by 20 percent of patient taking placebo and 67 percent of patients taking quercetin. In the 17 patients who took the Quercetin supplement, 82 percent had at least a 25 percent improvement in their symptom score. Overall, the authors noted that quercetin “provides significant symptomatic improvement” in men who have chronic nonbacterial prostatitis/chronic pelvic pain syndrome. (Shoskes 1999)
Quercetin Health Benefits for Bacterial Prostatitis
A prospective, randomized study was conducted to determine the therapeutic effect of quercetin and curcumin and saw palmetto and stinging nettle extracts compared with the antibiotic prulifloxacin in men who had chronic bacterial prostatitis. A total of 143 patients were enrolled, and they were split into two groups: Group A (106 patients) received both prulifloxacin (600 mg daily) plus ProstaMEV and FlogMEV for 14 days; Group B (37 men) received the antibiotic only. After one month, 89.6 percent of men who received the herbal formulas had no symptoms of prostatitis compared with only 27 percent of the men in the antibiotic-only group. Six months after the intervention portion of the study ended, no patients in Group A had recurrent of prostatitis compared with two patients in Group B. The authors concluded that the association of quercetin, curcumin, saw palmetto, and stinging nettle extracts can improve the clinical efficacy of prulifloxacin in men who have chronic bacterial prostatitis. (Cai 2009)
Quercetin Health Benefits for Chronic Prostatitis
A more recent study was conducted at Cleveland Clinic and included 100 men who had chronic prostatitis/chronic pelvic pain syndrome. The study used a multimodel therapy based on the UPOINT phenotype (e.g., urinary: alpha blocker or antimuscarinic; organ-specific: quercetin; tenderness: physical therapy; psychosocial; infection; and neurologic/systemic). The men participated in the therapy for 26 weeks, and the main endpoint was a minimum 6-point decline in NIH-Chronic Prostatitis Symptom Index (CPSI).
A median of 3 UPOINT domains were positive: organ-specific (70%), tenderness (64%), and urinary (59%). At a median 50-week follow-up, 84 percent of the men had a least a 6-point decline in CPSI. The number of domains and initial CPSI were not predictors of a man’s response. Although no one domain predicted outcome, quercetin use was associated with a greater CPSI decrease. (Shoskes 2010)
Quercetin Health Benefits for Prostate Cancer
Based on previous research that showed quercetin to possess antitumor activity, investigators at State University of New York at Buffalo studied the effect of quercetin on the ability of prostate cancer cell lines to form colonies. They observed that at concentrations of 25 and 50 micro M, quercetin significantly inhibited the growth of both moderately aggressive DU-145 prostate cancer and highly aggressive PC-3 prostate cancer cell lines, but had no affect on the poorly aggressive LNCaP prostate cancer cell line. Quercetin also significantly inhibited the expression of certain oncogenes and genes that control specific phases of the cell cycle and “reciprocally up-regulated the expression of several tumor suppressor genes.” The authors concluded that their results “provide a scientific basis for the potential use of flavonoids as nutraceuticals in the chemoprevention of cancer.” (Nair 2004)
Quercetin has also demonstrated the ability to interrupt the spread of prostate cancer (metastases) and to promote cell death. A study published in Molecular and Cellular Biochemistry reported that quercetin was able to decrease the activity of specific enzymes known to be involved in tumor invasion and metastases. This finding led the authors to note that quercetin could be developed as a chemopreventive agent for metastatic prostate cancer. (Vijayababu 2006) The ability of quercetin to promote and enhance cell death in human prostate cancer cell lines has also been shown in several studies conducted at the University of Pittsburgh. (Kim 2007; Lee 2008) A more recent study from the University of Madras suggests that quercetin can decrease the survival of androgen-independent prostate cancer cells by changing the expression of insulin-like growth factor signaling and inducing apoptosis, which could make the supplement useful in cancer patients. (Senthilkumark 2010)
Quercetin Health Benefits for BPH
In a study published in the Journal of Endocrinology, scientists reported on their evaluation of the effect of quercetin and the drug finasteride (Proscar) on the prostate gland in rats. Administration of quercetin (doses of 50, 100, or 150 mg quercetin per kg of body weight) along with finasteride resulted in a 31.8%, 40.0%, and 48.2% reduction, respectively, in prostate weight. The authors concluded that quercetin works with finasteride to reduce prostate weight through a cell cycle-related pathway that may function independent of androgens. (Ma 2004)
How to Take Quercetin
Do not exceed 1 gram daily of quercetin without consulting your healthcare provider. Side effects may include headache and stomach upset. (University of Maryland)
References for Quercetin Health Benefits:
Cai T et al. Serenoa repens associated with Urtica dioica (ProstaMEV) and curcumin and quercitin (FlogMEV) extracts are able to improve the efficacy of prulifloxacin in bacterial prostatitis patients: results from a prospective randomized study. Int J Antimicrob Agents 2009 Jun; 33(6): 549-53
Kim YH, Lee YJ. TRAIL apoptosis is enhanced by quercetin through Akt dephosphorylation. J Cell Biochem 2007 Mar 1; 100(4): 998-1009
Lee DH et al. Role of Bax in quercetin-induced apoptosis in human prostate cancer cells. Biochem Pharmacol 2008 Jun 15; 75(12): 2345-55
Ma Z et al. Reduction of rat prostate weight by combined quercetin-finasteride treatment is associated with cell cycle deregulation. J Endocrinol 2004 Jun; 181(3): 493-507
Nair HK et al. Inhibition of prostate cancer cell colony formation by the flavonoid quercetin correlates with modulation of specific regulatory genes. Clin Diag Lab Immunol 2004 Jan; 11(1): 63-69
Senthilkumar K et al. Quercetin regulates insulin like growth factor signaling and induces intrinsic and extrinsic pathway mediated apoptosis in androgen independent prostate cancer cells (PC-3). Mol Cell Biochem 2010 Nov; 344(1-2): 173-84
Shoskes DA et al. Quercetin in men with category III chronic prostatitis: a preliminary prospective, double-blind, placebo-controlled trial. Urology 1999; 54(6):960-63.
Shoskes DA et al. Phenotypically directed multimodal therapy for chronic prostatitis/chronic pelvic pain syndrome: a prospective study using UPOINT. Urology 2010 Jun; 75(6): 1249-53
Vijayababu MR et al. Quercetin downregulates matrix metalloproteinases 2 and 9 proteins expression in prostate cancer cells (PC-3). Mol Cell Biochem 2006 Jul; 287(1-2): 109-16