NASA Studies Find Omega-3 May Help Reduce Bone Loss
WASHINGTON -- 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 NFKB. NFKB
is involved in immune system behavior and the inflammation process.
The activation of NFKB in different tissues can lead to bone and
muscle loss.
In a study of astronauts returning from short-duration shuttle
missions, researchers found that NFKB 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 NFKB activation could serve as a countermeasure to bone
loss.
A ground-based bed rest study was conducted on 16 subjects with the
evaluations performed after 60 days. Bed rest simulates some of the
effects of weightlessness, including muscle and bone loss. During the
study, higher intake of omega-3 fatty acids was associated with less
bone loss.
Based on these studies, the investigators evaluated bone loss in
astronauts and compared their findings to reported fish intake during
spaceflight. Researchers found that astronauts who ate more fish lost
less bone mineral after four-to-six-month spaceflights. Tracking fish
consumption is not as accurate as determining exact diet and omega-3
fatty acid intake, but these data were not available.
"These results are very exciting, and provide initial evidence that
nutrition may be a key factor in mitigating bone loss in astronauts."
said Scott Smith, a nutritionist at NASA's Johnson Space Center in
Houston and one of the paper's authors.
The studies were conducted by a team of scientists across multiple
disciplines at Johnson. Smith and Sara Zwart lead the center's
Nutritional Biochemistry Laboratory. Duane Pierson and Satish Mehta
work for the Microbiology Laboratory and led the shuttle-based
studies. Steve Gonda, a NASA scientist and a co-author, died before
publication of the studies.
To view the paper on the Internet, visit:
http://www3.interscience.
For information about NASA and agency programs, visit:
http://www.nasa.gov
Source: NASA
