The more isoflavone-containing soy products a young woman eats, the lower her odds for developing invasive breast cancers, according to research presented at a meeting of the American Association of Cancer Research in Philadelphia...

...The study included 683 women with breast cancer and 611 women without the disease. It found that participants who consumed the most isoflavones had a 30% lower risk of developing an invasive tumor.

Examining the data more closely, researchers found that among premenopausal women, those who consumed the most isoflavones had a 30% decreased risk of early, stage I disease, a 70% decreased risk of having a tumor larger than 2 centimeters, and a 60% decreased risk of having stage 2 breast cancer. These connections were not seen among postmenopausal women, the researchers reported...