Soy Compound May Bolster Women's Bones
Genistein, Found in Soy, May Boost Bone Density in Postmenopausal Women With Osteopenia
June 18, 2007 -- Genistein, a compound found in soy, may strengthen the
bones of women at risk for osteoporosis.
So say Italian researchers including Francesco Squadrito, MD, of Italy's
University of Messina.
They studied 389 postmenopausal Italian women with osteopenia, in which bone
mineral density is less than ideal but not as severe as osteoporosis.
First, the women got DEXA (dual X-ray absorptiometry) bone mineral
density scans of their upper thigh bone (femoral neck) and lower (lumbar)
spine. Next, they followed a low-fat, healthy diet for a month. Then
the researchers split the women into two groups.
One group of women got pills containing genistein, calcium carbonate, and
vitamin D. The dosage was "similar to that in vegetarian Asian diets," write
The other group received similar pills without genistein (placebo). The
women took their pills daily for two years without knowing if the tablets
During that time, the women got annual DEXA scans of their femoral neck and
lumbar spine. They were evaluated every three months for problems including
breast tenderness, hot flashes,
depression, gastrointestinal symptoms, irritability, insomnia, and vaginal
Better Bone Density
After two years, the DEXA scans showed increases in bone mineral density in
women taking genistein.
Bone mineral density dropped during the same period in women taking the
The researchers didn't gather information on fractures, so they're not sure
if genistein's effects mean fewer fractured or broken bones.
Genistein's chemical structure resembles estrogen, the female sex hormone
that protects bones and fades after menopause, the researchers note in the
Annals of Internal Medicine.
Because of those estrogen-like properties, "caution is needed when
administering genistein, especially in patients at high risk for endometrial or
breast cancer," write Squadrito and colleagues.
However, the study shows that the uterus lining (endometrium) wasn't thicker
in women taking genistein than in those taking the placebo.
Gastrointestinal side effects caused 37 women taking genistein and 15 taking
the placebo to quit the study.
Based on the results, Squadrito's team calls for studies testing genistein