How does soy affect women

A pilot study from found that both soy phytoestrogens and S-equol supplements were helpful aids to stop hot flashes. But their effects varied: For women who experienced more than eight hot flashes per day, S-equol supplements were a more effective treatment. For women with fewer hot flashes, both supplements proved moderately effective. Many soy studies are funded by industry groups — a predicament that can make our understanding of phytoestrogens more murky. When studies are funded by the industry — say, a large company that sells soy products — results may be cherry-picked to show only the benefits of the plant.

On the other hand, if a competing industry decides to recruit researchers to look at soy, the results may be tailored to only mention its negative effects. The results might sway consumers to purchase or avoid a certain product — leaving scientific research that can seem conflicting or limited. That sentiment is echoed by Frank Sacks, a Harvard University professor who studies cardiovascular disease prevention.

He studied the effects of soy on cholesterol and hormone levels under funding from the American Heart Association in There are some situations where it may be best to stay away from soy, but that generally differs from person to person.

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Sign Up. Already a subscriber? Want more? More From Discover. The authors suggested that female vegetarian patients with subclinical hypothyroidism may need more careful monitoring of thyroid function. However, the authors also found a benefit on of reduced cardiovascular risk factors in the high phytoestrogen group, with a significant reduction in insulin resistance, inflammatory markers, and blood pressure.

The effect of soy on thyroid function needs further examination. The contents of this website are for educational purposes and are not intended to offer personal medical advice.

You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The Nutrition Source does not recommend or endorse any products. Skip to content The Nutrition Source. Harvard T. The Nutrition Source Menu. Search for:. The Takeaway: Soy is a unique food that is widely studied for its estrogenic and anti-estrogenic effects on the body.

Studies may seem to present conflicting conclusions about soy, but this is largely due to the wide variation in how soy is studied. Results of recent population studies suggest that soy has either a beneficial or neutral effect on various health conditions. Soy is a nutrient-dense source of protein that can safely be consumed several times a week, and is likely to provide health benefits—especially when eaten as an alternative to red and processed meat.

Heart Disease Soy protein took center stage after research showed that it might lower levels of harmful cholesterol. Hot Flashes Hormone replacement therapy has traditionally been used as an effective treatment for hot flashes and other unpleasant symptoms that accompany menopause, but its long-term use carries concerns of an increased risk of some diseases including breast cancer and stroke.

Of all ethnicities, Asian American women tended to have the highest isoflavone intakes at about 6 mg. The authors noted that American women appeared to benefit from eating smaller amounts of soy.

The most frequent sources of soy foods were not whole or minimally processed soy foods, but rather soy sauce, breakfast or diet drinks, tofu, diet bars, and soy protein isolate powder. The authors concluded that soy isoflavones eaten at levels comparable to those in Asian populations may reduce the risk of cancer recurrence in women receiving tamoxifen therapy and does not appear to interfere with tamoxifen efficacy. However, the findings need to be confirmed because they were mainly in subgroups and could be due to chance.

Prostate Cancer The incidence of prostate cancer is highest in Western countries and lowest in Asian countries, where soy foods are a regular part of the daily diet. Memory and Cognitive Function Menopause has been linked with changes in mood and memory impairment. Thyroid Soy may interfere with thyroid hormone medication used to treat hypothyroidism.

Meta-analysis of the effects of soy protein intake on serum lipids. New England Journal of Medicine. Code of Federal Regulations. Health claims: Soy protein and risk of coronary heart disease.

Soy protein, isoflavones, and cardiovascular health: an American Heart Association Science Advisory for professionals from the Nutrition Committee. FDA Statement. Statement from Susan Mayne, Ph. October 30, Phytoestrogens for menopausal vasomotor symptoms.

Cochrane Database Syst Rev. Quantitative efficacy of soy isoflavones on menopausal hot flashes. British journal of clinical pharmacology. Phytoestrogens for treatment of menopausal symptoms: a systematic review. Kronenberg F, Fugh-Berman A. Complementary and alternative medicine for menopausal symptoms: a review of randomized, controlled trials.

Annals of internal medicine. Nonhormonal therapies for menopausal hot flashes: systematic review and meta-analysis. Meta-analysis of soy intake and breast cancer risk.

Journal of the National Cancer Institute. Diet and breast cancer: a review of the prospective observational studies. Linos E, Willett WC. Soy is often promoted as a healthy protein alternative for people who would rather not eat meat. Research about the effects of soy on cancer risk reduction has been mixed. Much of it has come from observing population groups such as the Japanese, who eat much more soy and begin eating it at a much younger age than people in Western countries.

In fact, the average woman living in East Asia eats about 10 times the quantity of soy foods as the average woman in the United States. Yet East Asian women have lower rates of hormone-receptor-positive breast cancer than women in the United States. The "soy story" and its possible connection to breast cancer is complicated by other factors. Most women living in Asia depend on soy as their main source of protein.

They consume only small amounts of beef, chicken, and pork — which means less animal fat and other possibly unhealthy substances such as growth hormones and antibiotics in these animal protein sources. Also, compared to the average woman in the United States, the average Asian woman:.

All of these other factors add up to produce a healthier lifestyle and a lower overall risk of breast cancer in Asian women living in Asia. It's not clear if soy isoflavones affect breast cancer, especially hormone-receptor-positive breast cancers. Isoflavones may affect hormonal therapy's ability to do its job if both of these molecules compete to get into the same estrogen receptors. If isoflavones deliver a weaker estrogen signal to the receptor compared to tamoxifen and your body's estrogen , then the isoflavones might be able to decrease breast cell growth that's estrogen-dependent.

But if the isoflavones give breast cells a stronger estrogen signal than tamoxifen, that's a problem.