Fifty years ago this month, the U.S. made history when three astronauts took a walk on the moon. While the nation celebrated the feat, NASA had concerns about the effects of low gravity on their astronauts and their ability to overcome negative gravitational effects once they were back on terra firma. The effects of low or zero gravity on humans has remained a focus for NASA as it prepares astronauts for even more daring—and lengthier—space trips, such as a potential journey to Mars. According to a new study, maybe NASA should consider packing a few bottles of wine.
On earth, the human body is always under the stress of the force of gravity. While gravity keeps all things grounded, it also helps our muscles stay in shape as we constantly work to bear myriad loads like, for example, our own weight. This is how bodybuilders increase their muscle size. The more force or weight they lift, the more the body counteracts that force by increasing its muscle mass.
However, gravity is far, far weaker in space, meaning there is very little stress or force to increase or stabilize muscle size. The moon and Mars also both have significantly weaker gravities than Earth. Beyond Earth's atmosphere, astronauts' muscles shrink and their bones weaken. When they spend extended amounts of time in space and then return home, muscle weakness is a huge issue.
Now, a preventative treatment for muscle weakness may come from an unusual source: Researchers from Beth Israel Deaconess Medical Center at Harvard University have found evidence that resveratrol may help protect against muscle atrophy. Resveratrol is a polyphenolic chemical compound found in the skins of grapes and other berries and often cited in reports on the potential health benefits of wine.
The team published its findings in Frontiers in Physiology. "While there is a relatively good understanding of the effects of microgravity on human physiology based on five decades of experience, the physiological consequences of partial gravity [such as gravity on Mars, which is 38 percent of Earth's] remain far less well understood," write the authors. "Resveratrol has been extensively investigated for its health benefits, including its anti-inflammatory, anti-oxidative, and anti-diabetic effects. [It] has also been shown to preserve bone and muscle mass."
Two dozen male rats were used in the study. They were fed normal food, but half of them were given resveratrol in water and the other half only water. Some of each group experienced normal Earth gravity, while the others lived in replicated Mars gravity.
How do you recreate Mars gravity in a lab? The researchers put the rats in special harnesses hung from above their cages for two weeks. During that time, they recorded the rats' front and rear paw grip force as well as the circumference of their calves. At the end of the two weeks the calf muscles were examined.
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The rats living under the simulated Mars gravity who just received water showed diminished calf circumference, grip and muscle weight. But the resveratrol group were almost at the same levels as the control group that ate the same food minus the resveratrol and lived under normal Earth gravity. In addition, the "'"resveratrol rats" appeared almost entirely insulated against loss of muscle mass, experiencing decreasing damage to gastrocnemius and soleus muscles, while calf muscle fibers and circumference suffered minor losses.
More research needs to be done, however, before astronauts pack any Merlot or resveratrol supplements. The researchers call this a modest study and believe more data is needed. "Taken together, our results highlight the therapeutic potential of resveratrol as a nutraceutical countermeasure to prevent muscle deconditioning in an animal model of Martian gravity. Further investigations should optimize the dose of [resveratrol] for the preservation of muscle function and explore the mechanisms involved."