Soy: Safe and Perhaps Even Beneficial for Breast Cancer Survivors

Because soy isoflavones have estrogenic properties, the safety of soy consumption by breast cancer survivors has been questioned. In a cohort study conducted in Shanghai, women (age range, 20–75) who received diagnoses of breast cancer from 2002 to 2006 were followed for a median of 3.9 years. Soy intake was assessed with a validated survey that was designed to measure consumption of soy-containing foods in Chinese people.

Among 5033 evaluable participants, 534 recurrences or breast cancer–related deaths occurred. Dietary soy intake was inversely related to breast cancer recurrence and mortality. Compared with the lowest quartile of soy intake, the highest quartile was associated with an adjusted hazard ratio of 0.7. This inverse relation wa…