SCOTTSDALE, AZ -- July 13, 2007 -- Twenty-four months of treatment with genistein has positive effects on bone mineral density (BMD) in postmenopausal women with osteopenia, according to results of a 2-year clinical study published in the Annals of Internal Medicine.
The paper, which details the safety and efficacy of genistein for the dietary management of osteopenia and osteoporosis, reports a significant gain in bone density among postmenopausal women taking genistein at both 12 and 24 months over both baseline and placebo.
The randomized, double-blind, placebo-controlled study found that 85% of the women taking genistein showed a gain in bone density.
In addition, women taking genistein with calcium and vitamin D achieved a gain in bone density of approximately 3% per year over baseline and 6% per year over those taking the placebo.
The study enrolled 389 postmenopausal women with a BMD <0.795 g/cm2 at the femoral neck and no significant comorbid conditions receiving treatment at three university medical centers in Italy. After the initial 4-week stabilization period during which the women received a low-soy, reduced-fat diet, 191 women were randomized to placebo and 198 to 54 mg of genistein daily for 24 months. Both the genistein and placebo tablets contained calcium and vitamin D.
All participants were monitored for vasomotor symptoms, vaginal bleeding, breast tenderness, endometrial thickness, depression, irritability, insomnia, and gastrointestinal (GI) symptoms, as well as for changes in hematologic, renal and liver function tests.
No adverse events were reported in the study and no changes were noted in any of the parameters measured except for mild GI symptoms.
Patients in the test group of the study used 54 mg/day of highly purified genistein isolated from soy along with calcium and vitamin D.
"The placebo in this study was not an inactive pill; instead it was the current standard of care for osteopenia - calcium plus vitamin D," noted principal investigator Francesco Squadrito, MD, Professor of Pharmacology and Head of Clinical Pharmacology, School of Medicine, University of Messina, Italy. "Unlike other research in this area, this study was controlled for soy intake and additional supplement use, either of which may confound the results of a study."
According to the National Osteoporosis Foundation, osteoporosis currently afflicts more than 10 million Americans, while an additional 34 million have osteopenia. Osteopenia is the required precursor to osteoporosis. The lack of safe, efficient therapy for osteopenia beyond lifestyle changes with calcium and vitamin D leaves many patients and physicians with a lack of options.
The study used a formulation of genistein marketed under the brand name Fosteum by Primus Pharmaceuticals, Inc. The formulation which was evaluated in this clinical study is highly concentrated and cannot be achieved simply through dietary change. According to Dr. Squadrito, "To obtain the amount of genistein found in two capsules of Fosteum, one would have to consume 26 pounds of soybeans or over two gallons of soy milk each day."
Since no other product contains the same genistein as found in Fosteum, Dr. Squadrito urges caution in transferring the information in his paper to supplements purporting to contain genistein: "Supplements contain much lower concentrations of genistein and have other, sometimes unidentified, compounds in addition to genistein."
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