Soy Sense

By Karen Kell

I have two neighbors, Ruth and Sarah, who are both nearly 70. Ruth eats a balanced diet that includes fresh produce and whole grains; Sarah eats mainly processed foods out of cans and boxes. Ruth has the posture of a ballerina; Sarah is bent over with a humped back because she has osteoporosis, a disease characterized by low bone mass and fragility that elevates the risk of a fractured hip, spine, and wrist.

Reduce the Risk

Sarah’s fate may be more common than Ruth’s. Eating too many processed foods, mineral-leeching sugars, and drinking phosporousladen sodas has created an epidemic of bone disease in the United States. The surgeon general predicts that four out of ten Caucasian women (those most at risk) aged 50 years or older will break a hip, spine, or wrist sometime during their lives due to thinning bones. The Centers for Disease Control and Prevention reports that more than 50 percent of American women over 50 have reduced bone density, and 16 percent have osteoporosis.

Building Strong Bones

New research says soy foods, in combination with bone-health mainstays like calcium, foods high in vitamin D, and weight-bearing exercise, may help stave off bone disease and degeneration. Soy is especially beneficial to women facing menopause because it is rich in natural plant chemicals called isoflavones, which exert an estrogen-like effect on the body to bolster bone density. Of the 21 studies on the effects of soy foods or isoflavone supplements on bone mineral density in perimenopausal and postmenopausal women, 14 found benefits on at least one bone site in the body, says Mark J. Messina, Ph.D., a leading expert on soy nutrition and adjunct associate professor of nutrition at Loma Linda University in California.

Reverse Bone Loss

One of the studies looked at 300 postmenopausal women over two years and found that those who were given isoflavone supplements experienced a 6 percent increase in spinal and hip bone density. This is especially significant, says Messina, because when women go through menopause, they can lose 10 to 15 percent of bone density in just five or six years. “Soy is no miracle food,” cautions Christopher Gardner, Ph.D., assistant professor of medicine at Stanford University, who has conducted clinical research on soy, noting that many studies have shown little or no benefit for bone health. But Gardner recommends soy for its folic acid, unsaturated fat, and other benefits.

Get the Right Serving

Messina recommends you eat two to three servings a day (a serving, or about 25 milligrams, is a cup of soy milk, 3 to 4 ounces of tofu, or W cup soy nuts, for example) to mirror what participants in clinical trials consumed: 50 to 80 mg of isoflavones per day. Messina stresses that traditional whole soy foods (tofu, some types of soy milk, soybeans, edamame, soy flour, some texturized soy protein) are the best sources of isoflavones. Highly processed soy products such as cheese crackers, burgers, and bars, have fewer isoflavones. Check labels on products such as soy milk and texturized vegetable protein for isoflavone content—those that have it usually aren’t shy about flaunting it.