Higher levels of omega-3 fatty acids in the blood may reduce the risk for hip fractures in postmenopausal（绝经后的） women, recent research suggests. Scientists analyzed red blood cell samples from women with and without a history of having a broken hip. The study showed that higher levels of omega-3 fatty acids from both plant and fish sources in those blood cells were associated with a lower likelihood of having fractured a hip.

In addition to omega-3s, the researchers looked at omega-6 fatty acids, which are generally plentiful in a Western diet. The study also showed that as the ratio of omega-6 fatty acids to omega-3s increased, so did the risk for hip fracture.

Though the study did not define the mechanisms for these relationships, the researchers hypothesized that inflammation may contribute to bone resorption（吸收）, the breaking down of bone caused by the release of cells called osteoclasts（破骨细胞）.

"Inflammation is associated with an increased risk of bone loss and fractures, and omega-3 fatty acids are believed to reduce inflammation. So we asked if we would see fractures decrease in response to omega-3 intake," said Rebecca Jackson, the study's senior author and a professor of endocrinology, diabetes and metabolism at The Ohio State University.

"One thing that was critically important was that we didn't use self-report of food intake, because there can be errors with that. We looked directly at the exposure of the bone cell to the fatty acids, which is at the red blood cell level," said Jackson, also associate dean for clinical research in Ohio State's College of Medicine. "Red blood cell levels also give an indication of long-term exposure to these fatty acids, which we took into account in looking for a preventive effect."

Broken hips are the most common osteoporosis-related fractures, with an estimated 350,000 occurring annually in the United States. About 20 percent of people die in the year following a hip fracture.

The research is published in a recent issue of the Journal of Bone and Mineral Research.