NASA 
May 11, 2010

NASA-sponsored studies have found that omega-3 fatty acids found in fish oil may play a role in mitigating bone breakdown that occurs during spaceflight and in osteoporosis. Ongoing research for decades has looked for ways to stop bone density loss in astronauts. The solution could have significant implications for space travelers and those susceptible to bone loss on Earth.

The studies' results are published in the May issue of the Journal of Bone and Mineral Research. The paper reports on four types of studies using cell culture, ground-based bed rest, and data from both space shuttle and International Space Station crew members. NASA studies bone density loss because it is one of the main effects of exposure to the weightlessness of space. Scientists hope to find ways to counteract the problem for astronauts on long-duration space voyages.

In a series of cell-based studies, scientists documented that adding a specific omega-3 fatty acid to cells would inhibit the activation of factors that lead to bone breakdown. This was true in both typical cell cultures and those designed to mimic weightlessness. The inhibited factor is known as "nuclear factor kappa B" or NFκB. NFκB is involved in immune system behavior and the inflammation process. The activation of NFκB in different tissues can lead to bone and muscle loss.

In a study of astronauts returning from short-duration shuttle missions, researchers found that NFκB activation was increased in blood cells collected at landing, and remained elevated for two weeks. These data provide evidence that inflammatory processes may be involved in some of the adaptation to microgravity and suggest that reducing NFκB activation could serve as a countermeasure to bone loss.