Soy and Breast Cancer: What is the Verdict?

Hello, everyone! I hope that you are not overwhelmed about the breast cancer information that is presented during Breast Cancer Awareness month. I think it is great that we have so any supporters to fight against breast cancer. I see so many women wearing pink ribbons for the cause, and men are getting involved too.  I wanted to discuss a hot topic these days, and that is soy and breast cancer. Soy, also known as phytoestrogens or isoflavones, is currently used for hot flashes and menopausal symptoms and is also being used in high protein foods (soy protein). Questions that have been raised include: does soy lower breast cancer risk or does it increase breast cancer risk? The evidence is not quite clear and actually may do both. Previous studies do show conflicting information but the evidence seems to suggest a small overall reduction in breast cancer risk. It may induce cell maturity which could lower one’s risk. Animal studies have also shown that soy may increase breast cancer cell spread by behaving like estrogen. When rodent mammary cells are exposed to isoflavones, the estrogen receptor is activated and causes normal cells and cancer cells to grow. So what is a woman to do? I have some recommendations about soy consumption:

  1. Women with breast cancer should avoid regular soy.
  2. Women who are at high-risk for breast cancer should also avoid regular soy.
  3. If you would like to add soy to your diet, you should consume it naturally in foods and avoid supplements. Soy is in tofu, soy milk and soy beans. Highly processed soy supplements may have more biological activity and need further study concerning their safety.
  4. If you have breast pain, soy is best avoided since it can also cause breast pain.

In conclusion, more good studies are needed to answer the questions about soy and breast cancer risk. Next week, I will discuss alcohol and breast cancer.

Added to Nutrition, Cancer, Women's Health on Fri 10/23/2009