Red wine compound could help astronauts keep their muscle mass

It's been said that red wine has health benefits, with studies suggesting it can help fight cancer, obesity, aging, and even cavities. Now, a new study may add muscle loss to the list. In tests on rats, a Harvard team has found that a red wine compound called resveratrol could help keep astronauts toned and healthy during trips in space or life on Mars.

Humans have evolved for life here on Earth, which means taking us out of this environment can lead to all sorts of health troubles. While we might not notice it in our day-to-day lives, it turns out that our muscles are given a baseline exercise routine by Earth's gravity, and without it they lose mass and strength pretty quickly. As such, astronauts living on the International Space Station (ISS) have to stick to a pretty rigorous regime to stay fit.

Mars-bound astronauts will no doubt need similar workouts, but with space at a premium in … well, space, there might not be room for bulky exercise equipment on the long journey. And the pressure doesn't lift on arrival either – Mars has just 40 percent of the gravitational pull of Earth.

"After just three weeks in space, the human soleus muscle (in the calf) shrinks by a third," says Marie Mortreux, lead author of the study. "This is accompanied by a loss of slow-twitch muscle fibers, which are needed for endurance. Dietary strategies could be key, especially since astronauts traveling to Mars won't have access to the type of exercise machines deployed on the ISS."

So the Harvard team set out to test how well one promising compound – resveratrol – might be able to reduce the effects of low gravity on the muscles of rats. To mimic that unearthly environment in the lab, the team fitted 24 male rats with a harness that suspended them by a chain from the ceiling of their cages. Using this technique, some rats experienced the equivalent gravity of Mars, while a control group just had normal Earth gravity.

In each of these groups, half drank normal water while the other half had theirs spiked with 150 mg of resveratrol per kilogram per day. All ate the same food, and the experiment ran for two weeks. Weekly the rats were weighed, and their calf circumference, front and rear paw grip force measured. After the 14-day period, their calf muscles were analyzed in more depth.

Sure enough, the lower gravity conditions reduced the rats' grip strength, calf circumference, muscle weight, and slow-twitch fibers. But the resveratrol did manage to stave off the worst of those effects. Rats that received treatment retained paw grip equal to that of the Earth-gravity rats that didn't receive supplements.

The mass of muscles like the soleus and gastrocnemius appeared to be completely protected by the resveratrol, and the loss of the slow-twitch fibers was also slowed. It wasn't a total success though. The deeper analysis showed that the treated rats still lost some calf circumference and average cross-sectional area of the muscles.

On the plus side, the supplements also didn't seem to affect the rats' food intake or body weight at the end.

While it's too early to determine the root of these findings, the team suspects the anti-inflammatory effects of resveratrol are helping to conserve the animals' muscle and bone, and improve their insulin sensitivity.

"Resveratrol treatment promotes muscle growth in diabetic or unloaded animals, by increasing insulin sensitivity and glucose uptake in the muscle fibers," says Mortreux. "This is relevant for astronauts, who are known to develop reduced insulin sensitivity during spaceflight."

Of course, these results are a far cry from declaring that astronauts should be guzzling red wine en route to the Red Planet. The team says that higher doses of resveratrol will need to be tested, with a bigger sample of both male and female rats and, eventually, humans.

There's also the fact that the jury is still largely out on the health benefits of resveratrol at all. But still, it's an interesting study, and the compound could end up as part of a routine supplement for the first human explorers on Mars.

The research was published in the journal Frontiers In Physiology.

Source: Frontiers via Eurekalert