What Menopausal Women Need to Know About Soy

You see advertisements “Soy Serves Up Healthy Benefits, and Relieves Menopausal Symptoms,” and many people believe this without any real study of whether it does. I know it didn’t relieve my symptoms.

There is the perception among many women that plant estrogens are "natural" and therefore safer tha
HRT, but this has never been proven scientifically. Further research is needed to fully characterize the safety and potential risks of phytoestrogens.

Promoters of soy products such as soy protein isolate, or phyto-estrogens extracted from soy, usually fail to mention that soy products are goitrogenic to humans. That means they depress thyroid function leading to goiter and other adverse changes in the thyroid gland. Low thyroid function is associated with weight gain, fatigue, osteoporosis, loss of hair, and difficult menopause. So, if you are taking soy for your menopause, it is depressing your thyroid and it may cause you to have any of these symptoms.
For example, researchers have shown that long-term use of phytoestrogens in postmenopausal women led to an overgrowth of the tissues lining the uterus, which can be a precursor to cancer. I wouldn’t be surprised if this is why I developed endometriosis and needed to have a hysterectomy when I was 37 years old.
Soy is one of many types of isoflavones. They are plant-derived estrogens, and are not alte
atives to estrogen. A woman that wants to avoid estrogen should not be taking soy. Recent trials have shown that soy failed to show effectiveness compared to a placebo sugar for relieving menopausal symptoms.

The FDA does not have control over the preparation. Therefore, ingredients can vary, even with the same manufacturer. Also, because of the lack of FDA control, manufacturers are not required to prove its safety, effectiveness or side effects. That is why you will see on supplement bottles “not approved by the FDA.” And this explains why you know more about side effects of prescription estrogen than about soy. Little is known about soy side effects, and even with the little research we have results are conflicting. Some studies show that soy can cause multiplication of breast cells, implying that it may increase breast cancer risk. So, the controversy continues. Due to massive public interest, research is beginning.

Charles Loprinzi, MD, a Mayo Clinic medical oncologist and one of the authors of a study said, "despite optimistic hopes that this soy phytoestrogen product would alleviate hot flashes, the scientific data from this study demonstrated that it did not help. Thus, we need to explore other means for alleviating hot flashes in women who choose not to use estrogen or progesterone preparations."
Susan Quella, principal investigator of the study and nurse coordinator for the NCCTG, said “the study originated after seeing numerous advertisements that include claims about the benefits of soy, without any science behind the claims.”