In a large prospective study of female breast cancer patients treated surgically, moderate soy intake was associated with a significant decrease in death and cancer recurrence during a 4 year follow-up.
A recent study published in the December 9, 2009 edition of the Journal of the American Medical Association provides more evidence of the safety of dietary soy intake in breast cancer patients.
Researchers found that a higher intake of soy foods was associated with a reduced risk of breast cancer recurrence as well as a lower risk of dying over a four year period following diagnosis.
Participants included 5,033 women in the Shanghai Breast Cancer Survival Study who were surgically treated for breast cancer. The women were enrolled between 2002 and 2006 and followed through June 2009. Intakes of soy protein and soy isoflavones were analyzed from several interviews and dietary questionnaires.
Over an average follow-up of about four years, women whose intake of soy protein was among the top 25 percent of participants had a 29 percent lower risk of death during follow-up and a 32 percent lower risk of recurrence compared to those whose intake was in the lowest quarter. When soy isoflavones were evaluated separately, the risk of dying over follow-up was 21 percent lower and the risk of recurrence was 23 percent lower for those whose intake was highest. The use of tamoxifen and hormone therapy were also associated with improved survival.
In this population-based prospective study, soy food intake was found to be safe and was associated with lower mortality and recurrence among breast cancer patients. The association of soy food intake with mortality and recurrence appears to have followed a linear dose response pattern until soy food intake reached 11 g/day of soy protein. No additional benefits on mortality and recurrence were observed with higher intakes of soy food. This study suggests that moderate soy food intake is safe and potentially beneficial for women with breast cancer.
Source: USANA Health Sciences
