Soy food prevents breast cancer

Eating soy food in childhood may help reduce the risk of developing breast cancer, a study published in the March 24, 2009 issue of Cancer Epidemiology Biomarkers & Prevention suggests.

The case-control study led by LA Korde at the National Cancer Institute and colleagues showed that those who ate soy food in childhood had their risk of breast cancer reduced by up to 60 percent.

The study involved 597 women with breast cancer, with 73 percent pre-menopausal, and 966 women without the disease from three ethnic groups: Chinese, Japanese, and Filipino, who were 20 to 55 years old and living in San Francisco-Oakland, California, Los Angeles, California and Oahu, Hawaii.

The researchers found that those who ate the highest amounts of soy food in childhood, adolescence and adulthood were at a 60 percent, 20 percent and 24 percent reduced risk of breast cancer respectively compared to those who consumed the least amounts.

The inverse association was observed among all three ethnicities, all three sites, and women born in Asia and the United States. Adjustments made for effects of westernization attenuated the associations with adolescent and adult soy intake, but the association still held for childhood soy intake.

"Soy intake during childhood, adolescence, and adult life was associated with decreased breast cancer risk, with the strongest, most consistent effect for childhood intake. Soy may be a hormonally related, early-life exposure that influences breast cancer incidence," the researchers wrote in their report.

Written by Dr. David Liu and edited by Heather Kelley