DHA May Prevent Bone Loss

WEST LAFAYETTE, Ind.--High consumption of DHA (docosahexaenoic acid) inhibited bone loss in an animal model of postmenopausal osteoporosis, according to new research published in The Journal of Nutritional Biochemistry (17, 4:282-89, 2006).

Researchers from Purdue University and Indiana University administered a high-polyunsaturated fatty acid (PUFA) diet with a ratio of omega-6s (n-6s) to omega-3s (n-3s) of 5-to-1, and a low-PUFA diet with a ratio of n-6 to n-3 PUFAs of 10-to-1, to ovariectomized (OVX) SpragueDawley rats for 12 weeks. Tests indicated the 5-to-1 ratio diet significantly elevated DHA levels in the periosteum, marrow, and cortical and trabecular bones of the femur. Dual-energy X-ray absorptiometry measurements of femur and tibia bone mineral content (BMC) and bone mineral density (BMD) showed high consumption of DHA inhibited bone loss among the animals. Rats fed a low-PUFA diet displayed the lowest overall serum concentrations of bone resorption biomarkers, whereas bone formation was lowest in animals administered a high-PUFA diet. Regardless of dietary PUFA content, DHA in the 5-to-1 ratio diet preserved rat femur BMC in the absence of estrogen.

The researchers concluded dietary ratio of n-6 to n-3 PUFAs and bone tissue concentration of DHA minimize femur bone loss as evidenced by higher BMC in OVX rats.