Ladies, if you haven't been convinced that soy and phytoestrogens from soy products are beneficial yet, here's more news: the estrogens found in soy and soy protein prevent breast cancer.
A major study published in June's edition of the American Journal of Clinical Nutrition (Am J Clin Nutr 89: 1920-1926, 2009) studied the diets of 73,223 Chinese women over a period of 7.4 years. They found that women who consumed the most soy estrogens, or isoflavones, from food were 59% less likely to develop breast cancer than women who consumed the least. Also, adolescent girls who consumed the most isoflavones from soy foods were 43% less likely to develop premenopausal breast cancer than girls who consumed fewer soy protein.
In the words of the study authors, "This large, population-based, prospective cohort study provides strong evidence of a protective effect of soy food intake against premenopausal breast cancer."
The reason soy estrogens work to prevent breast cancer is because isoflavones have anti-estrogenic - as well as anticarcinogenic - properties. Soy estrogens don't mimic estrogen in the body as many people think they do (unless estrogen levels are dangerously low), but actually lower estrogen levels by keeping estrogen from entering the cells. By blocking cell receptors, soy estrogens keep estrogen levels from climbing high enough to encourage the growth of cancer cells. Also, isoflavones have cancer-fighting properties to boot.
Soy is a huge area of confusion in popular culture (in the U.S.) but not in scientific circles - now you can see why. If you need more encouragement, see past posts citing studies on soy and reproductive cancer. There are tons!
So whether it's tempeh, tofu, soy milk, or edamame - enjoy worry free.
Labels: soy estrogens