| A new study published in the May 2000
issue of the Journal of the American College of Cardiology finds that
phytoestrogens (natural chemicals found in many plants) provide women with many of the
same benefits as hormone replacement therapy (HRT) without
increasing the risk of breast or uterine cancers. In addition to treating hot flashes and
other menopausal symptoms, research has shown that phytoestrogens may help prevent breast cancer, heart
disease, and osteoporosis (a degenerative bone
disease). Phytoestrogens are found in soybeans, flaxseeds, black cohosh, alfalfa spouts,
and other plants. Researchers
believe that phytoestrogens may provide multiple benefits to women because they help
balance hormone levels in the body. A lack of the hormone estrogen has been shown to
increase the risk for osteoporosis and heart disease. However, too much estrogen may
contribute to breast or uterine cancer because some cancer cells depend on estrogen for
survival.
Researchers say phytoestrogens (also
called isoflavones) could be especially useful because they can act like weak estrogens
when necessary, providing hormonal protection against menopausal symptoms (hot flashes,
vaginal dryness, etc.), heart disease, and osteoporosis. On the other hand, phytoestrogens
can also block estrogen from reaching estrogen receptors in cells, protecting the body
from breast and uterine cancer.
In a study conducted at the Stanford
University Medical Center in California, women who were given a soy-based diet lowered
their total cholesterol levels by 9% and LDL cholesterol levels ("bad
cholesterol") by 13% compared to women who did not include soy in their diets.
Phytoestrogens were also shown to protect against menopausal symptoms, osteoporosis, and
decrease the risk for breast cancer.
Research on phytoestrogens is
relatively new, though. According to Lynette Wroblewski Lissin, MD and John P. Cooke, MD,
phytoestrogens seem to provide several benefits, including protecting high risk patients
from developing heart disease. However, further studies on phytoestrogens need to be
conducted. Presently, Dr. Lissin and Cooke believe women at high risk of cardiovascular
disease may benefit from a soy diet, especially if they do not have a family or personal
history of breast or uterine cancer.
The average amount of soy recommended
for women to help protect against breast cancer is 35 grams per day—also the average
amount Asian women consume per day. 60 grams is the maximum amount of soy used in clinical trials involving breast cancer patients.
Products rich in phytoestrogens include soy milk, tofu, roasted soy nuts, soy protein
powders, and tempeh. Not all soy products contain phytoestrogens (also called
isoflavones).
Additional Resources and
References
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