Women's Health

Soy and Menopause: How to Advise Patients

Research has found a link between soy and menopause and that a soy diet may reduce hot flashes and night sweats for women going through menopause.

Most menopause symptoms are the result of low estrogen levels. Since the early 2000s, when health concerns caused people to stop using hormone replacement therapy, many women and their doctors have looked for alternative ways to manage symptoms. A soy diet has gained increasing attention lately as a possible treatment option, but how well does it work?

Why Soy?

Soy-based foods contain isoflavones, a type of phytoestrogen. Phytoestrogens are believed to work similarly to estrogen, and may be able to relieve menopause symptoms such as hot flashes and night sweats.

What Does the Research on Soy and Menopause Say?

In short, the research on soy and menopause is inconclusive. For seemingly every study that finds that a soy diet improves hot flashes and other symptoms, another study finds that there's no effect. A review in The Journal of Nutrition evaluated 10 studies from the past two decades that focused on soy and its effect on vasomotor and urogenital symptoms, and found conflicting results. Likewise, a review from Virginia Tech found that some studies identified benefits of a soy diet for hot flashes and cognitive functioning, while others did not.

Researchers have noted that most studies evaluating soy have been fairly small with short durations, lasting only a few months. The University of Rochester Medical Center (URMC) finds that soy isoflavones are about one-third as effective as estrogen for reducing hot flashes, but URMC does suggest that daily soy consumption over the long term can reduce inflammatory proteins related to menopause.

What to Recommend to Patients

Given the conflicting evidence, choosing whether or not to advise patients on a menopause soy diet will likely come down to each individual. Which medications has she tried? Is she requesting a soy diet? How severe are her menopause symptoms?

Incorporating a reasonable amount of soy foods into a daily diet doesn't pose health risks. The key is to recommend whole foods, rather than processed soy. Kaiser Permanente notes that isoflavones are short-acting, so it's best to spread them throughout the day to get the greatest benefits.

Common sources of soy and their isoflavone content (in milligrams) include:

  • Miso (1/2 cup = 59 mg).
  • Boiled soybeans (1/2 cup = 47 mg).
  • Soybeans, dry roasted (1 ounce = 37mg).
  • Tempeh (3 ounces = 37 mg).
  • Soy milk (1 cup = 30 mg).
  • Tofu (3 ounces = 20 mg).
  • Boiled edamame (1/2 cup = 12 mg).

For example, a patient could have one cup of soy milk at breakfast, a snack of dry, roasted soybeans in the afternoon, and a side of boiled edamame at dinner.

Some people have an intolerance to soy, and too much can cause stomach pain, bloating, gas and diarrhea. Caution your patients to watch for signs of gastrointestinal distress as they add soy, and to stop if it causes them problems.

Despite conflicting evidence, there's a real chance that for some women, a soy diet may improve menopause symptoms. Discuss the connection between soy and menopause with your patients and advise them on how they can incorporate soy-based foods into a healthy eating pattern.