Menopause describes the phase in a woman's life when her body stops producing eggs, the levels of estrogen and progesterone drop and menstrual flow becomes less frequent, sporadic and then stops completely. Doctors consider a woman in post-menopause 12 months after her last menstrual cycle. Although a natural part of life, menopause triggers a variety of symptoms, most caused by the drop in hormones. Soy isoflavone, a phytoestrogen compound, affects hormone levels and may provide relief of menopause symptoms.
Menopause Symptoms
During the months and years leading up to menopause and for years following menopause, the change in hormone levels affects a variety of biological functions, resulting in uncomfortable symptoms. Common symptoms include hot flashes and night sweats, trouble sleeping, vaginal dryness, mood swings, thinning hair, an increase in abdominal fat and loss of breast tissue.
Menopause Treatments
As a natural phase in a woman's life, menopause does not require treatment. For many women, however, the symptoms become severe enough to interfere with daily activities. For this reason, some women seek treatment to reduce the frequency and severity of symptoms. Taking synthetic hormones, a treatment known as hormone replacement therapy, or HRT, can provide relief from symptoms. The Women's Health Initiative, a 15-year study of hormone replacement therapy conducted by the National Institutes of Health and involving almost 162,000 healthy postmenopausal women, found that taking synthetic hormones increases your risk for stroke, heart attack, blood clots, breast cancer and colorectal cancer. These findings prompted many women and doctors to look for alternative therapies.
Isoflavone Action
Soybeans, the edible seed of the soy plant, serve as a good source of protein. The high protein content with no dietary cholesterol and little saturated fat makes soy a healthy alternative to animal protein sources. The U.S. Food and Drug Administration approved a health claim for soy that states eating 25 g of soy protein per day as part of a low saturated fat and low-cholesterol diet reduces your risk for heart disease. In addition to protein, soy contains the phytochemical known as soy isoflavone. Isoflavone binds to estrogen receptors in the body and can mimic estrogen in some tissues and block the effects of estrogen in other tissues. Scientists continue to study the effects of soy isoflavone for women in menopause to determine if it can mimic estrogen enough to reduce menopausal symptoms.
Research
An analysis of 47 studies published in the March 2009 issue of "Human Reproduction Update" found that when postmenopausal women consumed soy isoflavones, they experienced a slight but insignificant increase in circulating estradiol, the active form of estrogen. Another study, published in the October 2010 issue of "Frontiers in Neuroendocrinology," analyzed several clinical trials that tested the effects of isoflavone on reducing the menopause symptoms of hot flashes and night sweats. The analysis found the association between isoflavone and menopause symptom relief weak and minimal. The most encouraging association between the consumption of soy isoflavone and menopause is the ability of isoflavones to improve bone mineral density, which can slow the progression of osteoporosis, a chronic disease common in postmenopausal women.
References
- Linus Pauling Institute: Soy Isoflavones; Victoria Drake; December 2009
- National Institutes of Health: Women's Health Initiative Findings
- Mayoclinic.com: Menopause Symptoms; July 2009
- "Human Reproduction Update"; Effects of Soy Protein and Isoflavones on Circulating Hormone Concentration; L. Hooper, et al.; March 2009
- "Frontiers in Neuroendocrinology"; The Pros and Cons of Phytoestrogens; Patisaul and Jefferson; March 2010
