Stronger bones thanks to omega 3 DHA

Increasing consumption of omega-3 fatty acids could increase the mineral content of bones and help the body produce a stronger, healthier skeleton. In particular,docosahexaenoic acid (DHA) would have the greatest benefits for bone health. The suggestion comes from the pages of the British Journal of Nutrition, which published a study finding that DHA is a vital constituent of bone marrow. The research is a collaboration between researchers from Purdue University (West Lafayette, USA), Indiana University School of Medicine (Indianapolis, USA), Korea Maritime University (Yeongdo-gu, South Korea) and the U.S. National Institutes of Health.

Clues from rat bones

The scientists, led by Bruce Watkins of Purdue University, came to this conclusion through a series of experiments conducted on rats. The animals involved in the study were bred to be deficient in Omega-3. Two days after birth, the rats were separated from their mothers and fed artificially with milk containing linoleic acid and different concentrations of fatty acids. A first group of rats was given 1% DHA, while a second group of animals receivedOmega-6 DPA (docosapentaenoic acid) and a third a mixture of 1% DHA and 0.4% DPA. The remaining young received only milk with linoleic acid. Finally, a control group was reared by their mothers, receiving a diet containing 3.1% alpha-linolenic acid, the Omega-3 precursor. At the end of the lactation period, all animals were weaned onto the same food. Once the rats reached adulthood, the authors analyzed the bone mineral density of the femur, tibia and lumbar vertebrae using a sophisticated X-ray-based technique.

DHA, an irreplaceable element

The researchers thus found that bone mineral concentration depends on both DHA and total Omega-3 fatty acid levels. The DPA-fed animals were found to have the lowest mineral content and the lowest mineral density in long bones such as the femur and tibia. At the same time, the researchers explained, these were also the animals with the highest DPA content in bone. The authors concluded that DPA is not sufficient to make up for DHA deficiency and ensure adequate mineral content in long bones. This suggests the critical role of this omega-3 fatty acid in bone health.

The role of omega-3s in bones

DHA, the researchers explain, accumulates in the femur at the level of the periosteum, the lining layer of bone. Conversely, the other important Omega-3,eicosapentaenoic acid (EPA), would not appear to be a vital constituent of the marrow and periosteum of developing bones.  

Source 

1. Li Y, Seifert MF, Lim SY, Salem N Jr, Watkins BA, "Bone mineral content is positively correlated to n-3 fatty acids in the femur of growing rats," Br J Nutr. 2010 Sep;104(5):674-85. Epub 2010 Apr 27