GCP Health Benefits
GCP health benefits (Genistein Combined Polysaccharide) include a possible ability to fight prostate cancer. The supplement GCP is a proprietary formula that is made up of genistein (a soy compound) that has been combined with polysaccharides provided by mushrooms using a process called fermentation.
GCP health benefits come from two sources. Genistein has mild estrogen-like properties while the mushrooms and their polysaccharides possess anti-tumor abilities and help stimulate the immune system.
How Does GCP Work?
To restore suppressed function of important immune system cells called T-cells, the body needs polysaccharides, and GCP is a rich source. T-cells recognize and distinguish mutated cells from healthy cells,and thus help maintain immunity. When the immune system is suppressed, mutated cells can slip through and cause disease.
A number of studies have shown GCP health benefits to include the potential to fight against prostate cancer. Here is what investigators have uncovered thus far.
GCP Health Benefits and Prostate Cancer
GCP was administered to a 63-year-old man with biopsy-proven prostate cancer. For six weeks before undergoing radical prostatectomy, the patient took 1.5 g of GCP daily. At the start of the study, the man’s PSA level was 19.4ng/mL, and by the end it had dropped to 4.2 ng/mL. The prostate tumor had grown significantly smaller as well. Evaluation of the removed prostate tissue did not show any cancer. The authors concluded that “the presented case does further support the possibility that GCP might be an alternative therapeutic option in advanced prostate cancer patients who have failed other forms of conventional therapy.” (Ghafar 2002)
In a study of 15 men with biopsy-proven prostate cancer, 1.5 g per day of GCP was taken daily 7 weeks before the men underwent radical prostatectomy. The mean PSA at the start of the study was 7.5 ng/mL, and 60% (9 of 15) of the patients were considered to be high-risk. At the end of the study and after the prostatectomies were performed, there was a significant difference in apoptosis (cell suicide) within the prostatectomy tissue specimens in men who had taken GCP compared with men who had not taken the supplement. The authors concluded that “despite a large percentage of preoperative high-risk patients, only one has exhibited biochemical recurrence to date.” (Shappley)
University of California (UC), Davis, researchers set out to determine whether a genistein-rich extract would lower PSA levels more than 50% in men with prostate cancer. Fifty-two men took capsules containing genistein three times daily for six months. The men were in one of five groups: after radical prostatectomy, after radiotherapy, after both prostatectomy and radiotherapy, hormonal therapy, and active surveillance.
Compared with before treatment, only 1 of 52 patients had a reduction in PSA levels greater than 50% and 7 had reductions less than 50%. All eight of these patients were in the active surveillance group. Among the remaining participants, 35 experienced disease progression and the remaining men were stable. The investigators concluded that the genistein-rich extract did not help men with prostate cancer when it was given alone. However, the supplement did seem to be effective for 8 of 13 men in the active surveillance group. These findings suggest more research is needed for men who choose active surveillance. (deVere White 2004)
In another UC Davis study, the investigators compared GCP health benefits in combination with three different anticancer drugs: bicalutamide, docetaxel, and the Src kinase inhibitor pp2 in four different prostate cancer cell lines. GCP enhanced the activity of docetaxel in all four prostate cancer cell lines while GCP plus bicalutamide improved activity in two cell lines. The authors concluded that GCP health benefits have “significant clinical potential in combination with docetaxel, bicalutamide or targeted agents” for the treatment of advanced prostate cancer. (Burich 2008)
In yet another UC Davis study, it was reported that GCP showed an ability to improve survival in mouse models of metastatic prostate cancer and hormone therapy. The positive results of this pre-clinical trial set the stage for human studies. (Ghosh 2013)
A team from Columbia University Medical School grew prostate cancer cells (androgen-sensitive [LNCaP] and androgen-independent [PC-3]) in various concentrations of GCP to determine the potential for the supplement as a chemopreventive agent. Over 72 hours, GCP significantly suppressed prostate cancer cell growth in both groups. The reduction was associated with apoptosis in the LNCaP cells but not in the PC-3 cells. GCP was also used in mice that had grafted prostate cancer tumors, and the authors noted a significant growth inhibition.
Overall, the authors concluded that “GCP has potent growth-inhibitory effects against prostate cancer cell lines…[and that] GCP has potential as an effective chemopreventive agent against prostate cancer cell growth.” (Bemis 2004)
A study appearing in Bioscience,Biotechnology & Biochemistry compared GCP health benefits with soybean extracts in inhibiting angiogenesis (formation of new blood vessels that can nourish cancer cells and tumors). The investigators found that GCP inhibited angiogenesis in chick membranes and the formation of new blood vessels induced by colon cancer cells. The activity of GCP was greater than that of soybean extract. (Miura 2002)
How to Enjoy GCP Health Benefits
No established dose has been established for GCP health benefits. However, the amount typically used in studies is 1.5 grams daily. No serious side effects have been reported.
Bemis DL et al. A concentrated aglycone isoflavone preparation (GCP) that demonstrates potent anti-prostate cancer activity in vitro and in vivo. Clin Cancer Res 2004 Aug 1; 10(15):5282-92
Burich RA et al. Genistein combined polysaccharide enhances activity of docetaxel, bicalutamide and Src kinase inhibition in androgen-dependent and independent prostate cancer cell lines. BJU Int 2008 Nov; 102(10): 1458-66
Ghafar MH et al. Regression of prostate cancer following administration of genistein combined polysaccharide (GCP), a nutritional supplement: a case report. J AlternativeComplem Med 2002; 8(4): 493-97
Ghosh P et al. Enhancing the effectiveness of androgen deprivation in prostate cancer by inducing Filamin A nuclear localization. University of California, Davis.
Miura T et al. Isoflavone aglycone produced by culture of soybean extracts with basidiomycetes and its anti-angiogenic activity.Biosci Biotechnol Biochem 2002 Dec;66(12): 2626-31
Shappley WV et al. Genistein combined polysaccharide: Effect on prostate tissue and biochemical recurrence following radical prostatectomy.
deVere White RW et al. Effects of a genistein-rich extract on PSA levels in men with a history of prostate cancer. Urology 2004 Feb; 63(2): 259-63