| Red
clover supplement containing isoflavones common in Asian diet inhibit
growth of prostate cancer cells Trinovin™, a nutritional supplement derived from red clover, caused early-stage prostate cancer cells to die in numbers over 5 times greater than that seen in untreated control patients, according to an article in the December issue of Cancer Epidemiology Biomarkers and Prevention. The findings may explain why Asian men, who have rates of precancerous prostate cells similar to those seen in men in Western countries, have a much smaller incidence of prostate cancer. One previously reported study, for example, found that 1.8 percent of men in China develop prostate cancer compared with 53.4 percent of American men. These findings led researchers to consider dietary differences between the cultures, particularly isoflavones. In this study, 20 patients with confirmed prostate cancer were given 160mg of the supplement daily, which provides isoflavone content comparable with that in the Asian diet. Treatment periods ranged from approximately 1 to 8 weeks. The men then underwent prostate surgery. Data were compared with a random sample of readily available archival data from 18 patients who received no treatment. Before and after treatment, investigators measured the following: serum prostate specific antigen, Gleason score, serum testosterone, incidence of apoptosis, and excreted isoflavone levels. For each patient, an average of 2,500 cells was counted. The incidence of apoptosis occurred more than 5 times more often (almost 1.5 percent versus 0.25 percent) in the supplement arm than in the archival data, specifically in regions of low-grade cancer (Gleason grade 1-3). No adverse incidents were reported in the treatment group. The supplement contains four isoflavones common in the Asian diet: biochanin, genistein, formononetin, and daidzein. Soy isoflavones, contained in common American supplements, generally do not contain all four compounds. "A link between diet and cancer is known from epidemiological studies that showed when Asian men move to Western countries, they develop cancer at the same rate as the Western population," said Alan Husband, M.D., author and director of research for the supplement manufacturer. "This is an exciting study that gives further support to the link between dietary isoflavones and prostate disease and may explain the difference in the incidence of prostate cancer in Asian compared to Western men." Prostate cancer is about twice as common
among African-American men as it is among white American men. It
is most common in North America and northwestern Europe. It is less
common in Asia, Africa, and South America. |