The key to keeping humans strong on Mars could be found in red wine. A Harvard study published Thursday reported that resveratrol, a compound in blueberries and the skin of grapes (and, by extension, red wine) could preserve muscle mass and strength against the reduced gravity on Mars.
Resveratrol is believed to have the effects of an antioxidant, and is studied for its anti-inflammatory and anti-diabetic properties. Researchers found that it significantly maintained muscle mass and strength in rats exposed to a simulation of Mars' gravitational pull, which is 40% that of Earth's. Lower gravity levels can weaken muscles and bones, presenting a challenge for astronauts on long missions to Mars.
"Resveratrol has been shown to preserve bone and muscle mass in rats during complete unloading, analogous to microgravity during spaceflight," lead author Marie Mortreux said in a release. "We hypothesized that a moderate daily dose would help mitigate muscle deconditioning in a Mars gravity analogue, too."
To simulate gravity on Mars, rats were placed in a full-body harness and suspended by a chain from the ceiling of their cage. For 14 days, 24 male rats were either exposed to normal loading similar to Earth, or 40% loading similar to Mars. Half the rats in each of those two groups received resveratrol in water, while the rest got plain water.
Each week, researchers measured the circumference of the rats' calves, and their front and rear paw grip force. Their calf muscles were analyzed at 14 days.
Rats exposed to simulated Mars gravity suffered from weakened grip, shrunken calf circumference and reduced muscle weight. But those that received resveratrol had front and rear paw grip comparable to that of the Earth rats that didn't get any resveratrol. The compound also preserved the muscle mass of the Mars rats.
Resveratrol did have its limits, though. It didn't fully preserve calf circumference in the rats. In line with previous research, it also didn't affect food intake or total weight.
"Resveratrol treatment promotes muscle growth in diabetic or unloaded animals, by increasing insulin sensitivity and glucose uptake in the muscle fibers," Mortreux said in the release. "This is relevant for astronauts, who are known to develop reduced insulin sensitivity during spaceflight."
The anti-inflammatory effects of resveratrol could help conserve muscle and bone, the study says. Scientists are testing this using other antioxidants like dried plums.
Future studies will need to look at the mechanisms involved in this result, and examine the effects of different resveratrol doses in males and females, Mortreux said. It'll also be critical to ensure there are no potentially harmful interactions between resveratrol and the other compounds astronauts get on space missions, she said.
Originally published July 18, 2:07 p.m.