CNRC Scientists Lead National Soy Supplement Study

CNRC researcher Dr. William Wong is leading a national study to determine the benefits of over-the-counter soy supplements in the prevention of osteoporosis in post-menopausal women.

The $4.5 million project, named OPUS (Osteoporosis Prevention Using Soy), will determine the benefits, safety and correct dosages of soy isoflavone supplements. The project will enroll 400 women at three sites across the country and follow them for two years.

"The use of over-the-counter soy isoflavone supplements is becoming common for postmenopausal women as prevention for osteoporosis," said Wong, a professor of pediatrics at Baylor College of Medicine. "But no study has been done to determine its long-term safety and the benefits for this use."

More than 20 million American women have osteoporosis. Postmenopausal women are particularly susceptible because estrogen production has stopped. Estrogen replacement has been shown to reduce bone loss and fractures, but it carries some risks.

"Hormone replacement therapy provides many benefits for some women, but the possible side effects have to be weighed," said Wong. "If we can determine that natural soy isoflavones would be beneficial in preventing osteoporosis, as well as provide relief for some symptoms of menopause, it would be a tremendous service."

Soy isoflavones have a chemical structure that is very similar to estrogen, with estrogenic activities that are present but in a weaker format, he said.

Although preliminary studies have indicated that soy isoflavones can help in preventing osteoporosis and reducing the symptoms of menopause, the studies were short-term.

"We need a long-term study that involves hundreds of volunteers to be able to give women and their physicians answers. Does this work or not? Is it safe over the long-term and how much should we give?" he said.

In the study, one-third of the participants will receive 120 mg. of supplements a day; one-third will receive 80 mg. a day; and one-third will receive a placebo. Each participant will take three tablets a day, along with a multivitamin and a calcium supplement.

As part of the study, which is funded by the U.S. Department of Agriculture, a plan has been established to disseminate the results to researchers, educators, healthcare professionals and consumers through Texas A&M University and the Cooperative Extension System. In addition to Wong, Drs. Paula Amato and Ronald Young with Baylor's Department of Obstetric and Gynecology, as well as Dr. Kenneth Ellis, O'Brian Smith, Kennard Fraley and Karen Konzelmann from the CNRC are working with the Baylor arm of the OPUS project.

Along with the Baylor site, women will be enrolled at the University of Georgia and the University of California at Davis.

To learn more about enrolling in this study, call the project's recruitment hotline: 713-798-6783: