Fish oil, which contains omega-3 fatty acids, may help prevent bone density loss in former astronauts, according to a study published in the Journal of Bone and Mineral Medicine.

To improve the loss of bone density in astronauts returning from space, a team of scientists from NASA observed the effects of omega-3 fatty acids on cells that contribute to the breakdown of bones. Known as nuclear factor kappa B or NFkB, this component can be found in many types of tissues, and cause inflammation and loss of bone and muscle density.

The researchers worked with astronauts who had just returned from spaceflights, and discovered that for two weeks after they returned, NFkB activity had increased the number of blood cells, which caused inflammation and bone density loss.

Furthermore, to simulate weightlessness on earth, the scientists performed a 60-day bed rest study and observed the effects on the bones and muscles. During this study, participants were given a high intake of omega-3 fatty acids, which proved to prevent bone loss.

The two studies showed that astronauts who consumed more fish at least four months after shuttle missions could prevent bone density loss.

Scott Smith, a nutritionist at the NASA Johnson Space Center, stated that “these results are very exciting, and provide initial evidence that nutrition may be a key factor in mitigating bone loss in astronauts.”

By the end of 2010, approximately 40 million people in the U.S. aged 50 years and older will be diagnosed with low bone mass, according to the International Osteoporosis Foundation.