Elevated prostate-specific antigen (PSA) reflects the presence of inflammation in the prostate, predisposing to prostate cancer. Normalization of the PSA value may prevent the development of prostate cancer. This randomized controlled trial investigated whether a combination of isoflavones and curcumin is able to lower PSA. 85 men who had received prostate biopsies but were free of prostate cancer were assigned to receive a supplement containing soy isoflavones (40mg) and curcumin (100mg) or placebo for 6 months. In the overall population there was no significant effects between the isoflavone/ curcumin combination and placebo. However, among the group of patients who had PSA >or= 10 mcg/ml at baseline and were treated with the isoflavone/ curcumin combination, PSA levels decreased significantly from 18.8 to 10.2 mcg/ml (P = 0.01). In vitro results also showed that this combination synergistically downregulated androgen receptor expression and PSA production in prostate cancer cells. Soy isoflavones and curcumin are capable of decreasing elevated PSA in humans and synergistically exert anticancer effects in prostate cancer cells. (Prostate. 2010 Jul 1;70(10):1127-33.) PMID: 20503397
