By David Liu, PHD

Friday Aug 17, 2012 (foodconsumer.org) -- A new study in the Aug 13, 2012 issue of International Journal of Cancer suggests that taking isoflavone supplements may help drastically reduce the risk for breast cancer in postmenopausal women.

The study led by B.A. Boucher of Prevention and Cancer Control, Cancer Care Ontario in Toronto, Ontario, Canada and colleagues showed taking any type isoflavone supplement was associated with a 25 percent reduced risk of breast cancer in postmenopausal women.

Botanical supplements which likely contain isoflavone, intake of which has been associated with reduced risk of breast cancer, according to the authors of the study report. 

The current study was meant to examine the association between ever use of 28 isoflavone supplements and breast cancer risk in Ontario, Canada.  The case-control study involved 3101 cases of breast cancer identified in 2002 and 2003 and controls 3471.

Several supplements including Natural HRT were found associated with 61 percent reduced risk of breast cancer in 58 users.  Using any type of isoflavone supplements in 332 women was correlated with 32 percent reduced risk when three or more types were used.  In 325 women who used any isoflavone supplement for more than five years, the risk was reduced by 25 percent, compared to those who did not use supplements.

Taking high doses of isoflavone supplements were consistently associated with reduced risk of breast cancer.  The risk reduction was confined to postmenopausal breast cancer for both individual and combined supplements.

The strongest  reduction in breast cancer risk was found in those who ever took high doses of three or more supplements (45 percent reduction) and for more than five years (53 percent reduction).

Estrogen-progesterone tumor receptor status did not seem to have an effect on the associations.

The researchers concluded "isoflavone supplements were associated with decreased postmenopausal breast cancer risk. Further research to examine these novel findings is warranted, given the low supplement use and potential limitations of our results."