A October 2000 Nagata C. Ecological study, showed the association between soy product intake and mortality from cancer in Japan. The scientists concluded: “The present study provides modest support for the preventive role of soy against stomach cancer. Soy protein intake was significantly correlated with stomach cancer mortality rate in men” and “soy product intake estimated as total amount as well as isoflavone and soy protein intake were significantly positively correlated with colorectal cancer mortality rates in both sexes.”
A 2000 study concluded the effects of soyabean in the diet on sex hormone concentrations in healthy adult males. Men consuming tofu for 4 weeks had lower testosterone-oestradiol ratios as well as changes in other hormone levels. “Thus, replacement of meat protein with soyabean protein, as tofu, may have a minor effect on biologically-active sex hormones which could influence prostate cancer risk.” (Habito RC and others Oct. 2000).