Scant days into the New Year and my thoughts are turning not to resolutions but to estrogen. Not very forward-looking I suppose, but it’s been on my mind since I learned some weeks ago that the tumor in my breast was one-hundred-percent estrogen positive. The oncologists seemed to like this as it means that--after the surgeries, chemotherapy, and radiation--the body will respond to an estrogen suppressant. This will increase the probability that I will be cured of cancer. Surely a good reason for celebrating the New Year.

And yet, the extent to which doctors have remarked on the high degree of estrogen in the tumor sticks in my craw. Here’s why: I’m remembering the early part of this decade when I took soy supplements to manage the side effects of menopause. Billed as “natural and dietary,” these products were, and still are, sold over the counter. They are FDA approved. I must say, the caplets and powders, which contained soy isoflavones (or phytoestrogens), worked like a charm. The hot flashes were kept to a minimum during the time I used these.*

When I first researched these products, not much information was available. Today, a quick internet search yields this from http://www.healthcastle.com/: “Studies found that soy could become ‘pro-estrogen’ in women with low levels of natural estrogen. In other words, concentrated soy supplements may add estrogen to the body and hence increase breast cancer risk in post-menopausal women.”**

Then there is this quote from a paper posted online by the Department of Food Science and Human Nutrition at the University of Illinois in Urbana-Champaign, Ill.: “The estrogenic soy isoflavone, genistein, stimulates growth of estrogen-dependent human breast cancer cells in vivo.” The tests are with mice at the moment. However, the implications are not good.***

As if further proof is needed to show what excess estrogen does in the body, there was the news in December 2009 of a study linking alcohol consumption to a recurrence of breast cancer in women. The study, funded by the National Cancer Institute, showed that drinking three or more alcoholic drinks per week seemed to increase the risk for breast cancer recurrence.

The study’s lead author, Dr. Marilyn Kwan of Kaiser Permanente in Oakland, Calif., noted, “It has been suggested that alcohol could increase the risk of breast cancer by increasing estrogen metabolism and circulating levels of estrogen, thus promoting growth of the tumor.”

I suppose anyone who has had cancer will ruminate on what could’ve caused it. I know the soy supplements are still popular, and they help a lot of people. Still, had I to do it over, I would run as far from these products as I possibly could. I hope anyone considering taking them works closely with their doctor before picking them off the store shelf.

*Soybeans are rich sources of phytoestrogens called soy isoflavones. Specific plant estrogens in soy include daidzein and genistein. http://www.drugs.com/drp/estroven-caplets.html

**http://www.healthcastle.com/soy-breastcancer.shtml

***http://carcin.oxfordjournals.org/cgi/content/full/22/10/1667