Consuming soy food can significantly lower death and recurrence risk in women with breast cancer, reveals a new study.
There were concerns regarding the safety of soy food consumption among breast cancer survivors, however, the new research suggests that moderate soy food intake is safe and potentially beneficial for women with breast cancer.
"Soy foods are rich in isoflavones, a major group of phytoestrogens that have been hypothesized to reduce the risk of breast cancer," said the authors.
"However, the estrogen-like effect of isoflavones and the potential interaction between isoflavones and tamoxifen have led to concern about soy food consumption among breast cancer patients," they added.
Lead researcher Dr Xiao Ou Shu, of Vanderbilt University Medical Centre, Nashville, Tenn., analyzed the data from the Shanghai Breast Cancer Survival Study, a large, population-based study of 5,042 female breast cancer survivors in China and studied the association between soy isoflavone intake with breast cancer recurrence and survival.
The team found that patients in the group with the highest intake of soy protein had a 29 percent lower risk of death during the study period, and a 32 percent lower risk of breast cancer recurrence compared to patients with the lowest intake of soy protein.
The adjusted 4-year mortality rates were 10.3 percent and 7.4 percent and the 4-year recurrence rates were 11.2 percent and 8.0 percent, respectively, for women with the lowest and highest groups of soy protein intake.
"The inverse association was evident among women with either estrogen receptor-positive or -negative breast cancer and was present in both users and nonusers of tamoxifen," the researchers added.
The study appears in Journal of American Medical Association.