Soy food doesn't affect breast cancer survival

Soy food is high in isoflavones which are phytoestrogens and some researchers are concerned that consuming soy food would increase risk of cancer recurrence and death among breast cancer survivors.

But new research suggests soy food is safe for breast cancer survivors and healthy women as well to consume. The study was presented at the American Association for Cancer Research 102nd Annual Meeting 2011.

For the study, Dr. Xiao Ou Shu of Vanderbilt University Medical Center analysed data pooled from four cohort studies including the Shanghai Breast Cancer Survival Study, the Life After Cancer Epidemiology Study, the Women's Healthy Eating and Living Study and the Nurses' Health Study, which involved 18,312 women at 20 to 83 who were diagnosed with invasive breast cancer.

Soy isoflavones intake was estimated for 16,048 patients at 13 months after diagnosis. Breast cancer outcomes were reviewed nine years after diagnosis.

Dr. Shu found the average intake of soy isoflavones in American women was 3.2 mg  per day. Those with intake of more than 23 mg per day were nine percent less likely to die and 15 percent less likely to have recurrence compared with those with their intake below the average intake. But the associations were not statistically significant, meaning that they may be due to chance work.

Dr. Shu said "Our results indicate it may be beneficial for women to include soy food as part of a healthy diet, even if they have had breast cancer.

Breast cancer is expected in more than 170,000 women each year in the U.S. and the disease kills about 50,000 annually in the country.

David Liu