Stephanie Lachapelle for Back1Researchers recently find that consuming modest amounts of soy proteins does not lessen lumbar spine bone loss in perimenopausal women.
A six-month study by researchers at Iowa State University indicated that consuming modest amounts of soy proteins could less lumbar spine bone loss in midlife women, but a new three-year study disproves those findings.
The first, six-month study in 2000 indicated that the isoflavones in soy protein slowed the loss of bone mineral density in the lumbar spine, the section of vertebrae near the pelvis that is often a site of bone loss for women approaching menopause. While this study seemed promising, researchers desired a greater sample size and a longer duration to be truly sure of the benefits of soy protein.
The researchers studied both the positive and adverse effects of 80-mg and 120-mg daily dosages of soy protein in 224 postmenopausal women. Bone mineral densities were recorded at the lumbar spine, total proximal femur (hip), femoral neck and whole body at several time points and compared them to identify any change in density. The team found that the 120-mg dosage of soy isoflavones had a small protective effect on the femoral neck bone density, but had no significant effect on any other area.
Ultimately, the team concludes from this study that soy isoflavone pills are not the easy fix for bone mineral density loss that contributes to osteoporosis. “We did not demonstrate an important biological effect on BMD or bone turnover," says main contributor D. Lee Alekel, professor of nutrition and associate director of the Nutrition and Wellness Research Center at Iowa State University.
Alekel cautions, however, that it may take time for public acceptance of this study and its implications in bone health.
