Soy May Protect Against Osteoporosis During Menopause

by Amy Hendel, P.A. Health Writer

Results from a new study recently presented at the Society for Endocrinology in Edinburgh suggest that a diet that includes soy, with its isoflavones, may help to prevent bone weakening and overall risk of osteoporosis.

What is osteoporosis?

Osteoporosis is a fairly common condition, especially prevalent in young women who diet rigorously, and older women in menopause, when bone density thins and bones become brittle and fragile due to loss of tissue. “Osteo” refers to bone and “porosis” means porous. Yearly, 9 million fractures worldwide occur due to osteoporosis. Bone loss is escalates during perimenopause and especially menopause, when declining levels of estrogen occur. Estrogen protects against bone density loss.

Osteoporosis does not cause falls but people with the condition have a greater risk of breaking a bone if they fall. Common fracture sites are wrists, hip and spinal vertebrae. Hip fractures in the elderly are associated with complications and premature mortality.

During a woman’s lifetime, half of all post-menopausal women will have an osteoporosis-related fracture, according to the U.S. Preventive Task Force.

Why might soy be helpful?

Certain compounds in soy, called isoflavones, are similar (though by no means identical) to estrogen in certain activities, so the theory is that they can mimic estrogen and help to maintain the integrity of the bone. Isoflavones are polyphenolic compounds that are capable of exerting estrogen-like effects.

Soy isoflavones

Soyfoods (the less processed the better) and soybeans are the only natural dietary source with measurable and relevant levels of isoflavones. In studies, isoflavones have been linked to reducing risk of breast and prostate cancers, and heart disease. Soy does not contain estrogen, but the isoflavones it has are “estrogen-like” since they bind at some of the estrogen receptors in the body. In some small studies, soy has also been shown to help with hot flashes - a common symptom of early menopause. Contrary to one strong myth, there is no evidence that soy has any effect on circulating hormone levels in men – it does not cause feminization when consumed as a regular part of a balanced diet.

The study

Two hundred women already in early menopause were given either a daily supplement with soy protein containing 66 mg of isolflavones, or a supplement with soy protein alone, for six months. By measuring certain proteins in the blood, investigators then evaluated the women’s bone activity.

Women on the soy diet with isoflavones had lower levels of certain proteins in the blood, indicating less bone loss. This represented a lower risk for developing osteoporosis. The women taking the soy proteins accompanied by isoflavones were also found to have lower risk of heart disease.

Conclusion from the studySince numerous myths surrounding the safety and efficacy of including soy in one’s diet continue to percolate, it’s important to note that researchers in this study suggest that soy protein with isoflavones is a safe and effective option for supporting bone health during menopause. In fact, it may be preferable to some conventional osteoporosis drugs that have noted side effects.

The 66 mg of isoflavones used in the study is comparable to eating a traditional Oriental diet, rich in soy foods. The researchers estimate that the average individual would normally only consume two to sixteen mg of isoflavones from a traditional western diet.

Best soyfood choices

The less processed the soy, the higher the level of active isoflavones. The following are “best” soyfood choices with amounts for one serving. It’s recommended to have about 2 to 3 servings of soy daily to appreciate the benefits of the isoflavones.

½ cup cooked soybeans 149 calories, 14.3 grams protein, 47 mg isoflavone

½ cup of tempeh 165 calories, 14.1 grams protein, 37 mg isoflavone

¼ cup soynuts 202 calories, 15 grams protein, 37 mg isoflavone

½ cup Tofu 94 calories, 10 grams protein, 20 mg isoflavone

1 cup Soymilk 79 calories, 6.6 grams protein, 30 mg isoflavone

A half cup of miso has about 59 mg isoflavone and tofu yogurt has about 21 mg isoflavone. It should be noted that there are newer variations of soymilk, lower in calories and fortified with calcium and vitamin D, both of which support bone health.

Is there a diet that emphasizes foods that support bone health?

There is no specific bone-building diet. In addition to consuming the two to three servings of isoflavone-rich soyfoods daily, you can also target foods that are rich calcium, magnesium, vitamin D and other minerals. Make sure that you and your family are eating a Bone Healthy Diet.


Medical News Today

Amy Hendel, P.A.
Meet Our Writer
Amy Hendel, P.A.

Known as "The HealthGal", Amy Hendel P.A. is a medical and lifestyle reporter, nutrition and fitness expert, health coach and brand ambassador. Trained as a physician assistant, she maintains a health coach private practice in New York and Los Angeles. Author of The Four Habits of Healthy Families, find her on Twitter @Healthgal1103 and on Facebook @TheHealthGal. Check “Daily Health News” at Her personal mantra? “Fix it first with food, fitness, and lifestyle.”