Essential fats may prevent bone loss.

• Position: Menopause

Maintaining a proper balance of dietary fats may ward off much of the bone loss associated with postmenopausal osteoporosis, states a study by scientists at the Indiana University School of Medicine, Bloomington, and Purdue University, West Lafayette, Ind.

The researchers found that diets with a low ratio of omega-6 fatty acids to omega-3 fatty acids minimizes the bone loss typically brought on by estrogen deficiency, which is common in post-menopausal females. Omega-6 is found in foods such as grains and beef, while omega-3 is contained in products like walnuts and salmon.

"Many people don't realize it, but our bones are not static structures," explains Mark Seifert, professor of anatomy and cell biology at Indiana University. Bones undergo a process called "remodeling," in which they continuously are broken down and rebuilt. Two types of cells govern this process--bone resorption cells, which remove small portions of bone, and bone building cells, which fill in the gaps. Estrogen blocks some of the inflammatory compounds associated with bone resorption, which may explain why osteoporosis typically progresses after estrogen levels fall with the onset of menopause.

"Our lab and others have shown that omega-3 fatty acids help promote bone formation," reports Bruce Watkins, professor and director of Purdue's Center for Enhancing Foods to Protect Health. "We also have shown that higher intakes of omega-6 fatty acids lead to an increased production of compounds associated with bone loss."

While both types of fats are essential for human health, diets with a high...