Study: High Amounts of Soy Intake Inversely Associated with Breast Cancer

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High Amounts of Soy Intake Inversely Associated with Breast Cancer

Keywords: BREAST CANCER - Soy Foods, Isoflavones, Asian Diet, Western

Diet, Phytoestrogens, Estrogen, Hormones

Reference: " Epidemiology of soy exposures and breast cancer risk, " Wu

AH, Yu MC, et al, Br J Cancer, 2008; 98(1): 9-14. (Address: Department

of Preventive Medicine, Keck School of Medicine, University of

Southern California, Los Angeles, CA 90089-9175, USA. E-mail:

annawu@... ).

Summary: In a review and meta-analysis of 8 studies (7 case-control

and 1 cohort) examining the association between dietary soy intake and

risk of breast cancer, high intake of soy by Asians was found to be

associated with a significant reduction in the risk of breast cancer.

Studies conducted among relatively high-soy-consuming Asian

populations found that subjects consuming at least 20 mg per day

isoflavones had a significantly reduced risk of breast cancer

(OR=0.71) and those consuming approximately 10 mg/day had a moderately

reduced risk (OR=0.88), compared to those consuming less than or equal

to 5 mg/d isoflavones. Meanwhile, studies conducted among relatively

low-soy-consuming Western populations - with soy intake ranging from

0.15 to 0.8 mg/day - did not find a protective effect of soy intake.

The authors conclude, " Thus, the evidence to date, based largely on

case-control studies, suggest that soy food intake in the amount

consumed in Asian populations may have protective effects against

breast cancer. "