Soy May Greatly Reduce Breast Cancer Risk
The risk of breast cancer before menopause is significantly lower for women with high intakes of soy, according to a large Chinese study published in the June 2009 issue of The American Journal of Nutrition.
The study was conducted by researchers from Vanderbilt University in Nashville, Tennessee and the Shanghai Cancer Institute. It included over 70,000 Chinese women who took part in the Shanghai Women's Health Study.
The participants were given a validated food-frequency questionnaire to assess dietary intake during adolescence and adulthood.
After 7.5 years of follow up, the researchers documented 592 cases of breast cancer.
The researchers found that women with higher intakes of soy foods during adolescence had a 43% reduction in pre-menopausal breast cancer risk.
Moreover, women who continued to have higher intakes of soy protein into adulthood had a 59% reduction in the risk of pre-menopausal breast cancer.
There was no association between soy and isoflavone intake and reduction in post-menopausal cancer risk.
Previous studies have shown that the isoflavones in soy are responsible for its cancer reducing properties.
Isoflavones are a type of plant polyphenol high in antioxidants. They can be found most abundantly in red clover, soy beans, chickpeas and alfalfa.
Isoflavones have been associated with a number of health benefits such asreduction of bone loss, alleviation of hot flashes, maintenance of heart health and reduction in the risk of prostate cancer.
Eating whole soy beans is the best way to increase your isoflavone levels but there are also some good soy food products and supplements available as well.
Other foods high in antioxidants like cranberries, blueberries, chocolate and green tea can provide similar health benefits, but soy appears to be statistically the best bet for reducing breast cancer risk.