Soy isoflavone intake and breast cancer risk in Japan: from the Takayama study.

Increased consumption of soy and isoflavone may decrease breast cancer risk in postmenopausal Japanese women.

This study investigated the correlation between the consumption of soy and isoflavone and the incidence of breast cancer in Japanese women. Using dietary questionnaires, researchers examined the soy and inflavone intakes of 15,607 women above 35 years recruited from the Takayama Study for 16 years. The breast cancer hazard ratio was also assessed in all the subjects.

Researchers found out that post-menopausal subjects who are frequent consumers of moderate or large amounts of soy and isoflavone had low breast cancer risk. According to this study, high intakes of soy and isofalavone did not affect breast cancer risk in premenopausal women. The findings of this study provide evidence that moderate or high consumption of soy and isoflavone may protect postmenopausal women against the development of breast cancer.