Women whose lifelong diet is rich in soy products appear to have a reducedrisk of breast cancer, new research suggests. Scientists at Honolulu's CancerResearch Centre of Hawaii and Vanderbilt University in Nashville, Tennesseefound that women with the highest levels of soy in their diet had about a 50per cent decrease in the risk of breast cancer compared to those with thelowest levels. They analysed the urine of women in Shanghai, China, for thepresence of the soy chemicals isoflavones. The researchers found those levelscorrelate well with soy intake, giving scientists a biomarker for soyconsumption. The group remarked that studies of Asian women who come tothe United States to live show a tendency to increase breast cancer risk overgenerations. Soy products contain compounds similar to estrogen, a female sexhormone, called phytoestrogens, which may play a role in breast cancer risk.The group suggested that the critical time for soy consumption for itsprotective effects may be prior to puberty, possibly even prior to birth.