Black and white women benefit differently from soy

A few important differences between the groups were found at the end of the trial:

• Abdominal fat, sometimes called “belly fat,” decreased by 7.5% in the women taking the soya shake, but increased by 8.8% in women taking the dairy shake. This type of fat is closely associated with cardiovascular disease.
• Visceral fat, which is distributed on the organs and is the most dangerous type of fat, decreased by 2.5% in the soya group and increased by 5.3% in the dairy group, however, this difference was not statistically significant.
• The researchers found that, when taking race into account, only the white women lost abdominal and visceral fat; African American women taking the soya shake did not experience improvement in body fat distribution.
• African American women on the soya shake lost weight while white women did not.
• Small changes in blood markers in the women using the soya shake suggested that they may have had slight improvements in blood sugar metabolism and generalized inflammation.

“Soya supplementation reduced abdominal fat in obese postmenopausal women,” the study’s authors said of their findings.

Reaping soya’s rewards

In addition to weight loss or better body fat distribution, women who eat soya may see other health improvements:

• Reduced menopausal symptoms. Women from societies where soya is eaten regularly are less likely to suffer from hot flushes, and a few studies have found that adding soya to a Western diet can decrease symptoms such as hot flushes and vaginal dryness.
• Lower blood pressure. Soya protein has been found to lower blood pressure in both men and women.
• Lower cholesterol levels. Eating soya foods such as tofu, tempeh, miso, and soya nuts can reduce total and LDL-cholesterol levels.
• Stronger bones. Some, but not all, studies have found that soya foods and supplements can preserve bone density in postmenopausal women.

(Am J Obstet Gynecol 2010;203:153.e1–9)