Women with high levels genistein, an estrogen-like compound found in soy, seem to have a lower risk of developing breast cancer, a new study suggests.
In this study, more than 24,000 middle-aged and older Japanese women gave blood samples and have their diets assessed. These women were followed for an average of 10 years.
The researchers separated the women based on their blood levels of genistein at the start of the study. Women with highest levels were 65 percent less likely to develop breast cancer than women with the lowest genistein levels. Breast cancer risk was not reduced in women with moderate levels of genistein.
Genistein is found in soybeans, chick peas and other legumes. This "plant estrogen" is an isoflavone that's structurally similar to the hormone estrogen. Scientists believe genistein binds to estrogen receptors in the body, blocking the women's own estrogen from coming in contact with breast cells. Less exposure to estrogen is known to reduce the risk of breast cancer.
While some studies have linked soy consumption with a lower risk of breast cancer, others have found no protective effect. Few studies have looked at the long-term benefits of eating a diet that is high in soy foods.
The author of this study note that Japanese women typically start consuming soy foods at a young age and it is unclear whether the findings extend to the women in Western countries.
Breast cancer is the most common form of cancer among Canadian women, with an estimated 22,400 new cases this year.
For more information on how you can prevent breast cancer with nutrition strategies, check out Leslie Beck's Nutrition Guide for Women.
This study was published in the Journal of Clinical Oncology.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.