According to NASA, it would take 9 months to reach Mars from Earth. With the space race moving ahead, researchers from Harvard University are finding answers to how to maintain the body strength on reaching Mars. They have found that resveratrol preserves the muscle mass and strength in the bodies of rats when they are exposed to the simulation of Mars gravity. The study has been published in the journal, Frontiers in Physiology.
In the space, being unchallenged by gravity the muscles and bones of the body weaken. The weight bearing muscles such as soleus muscle in calf are most badly affected. Dr Marie Mortreux, lead author of the study said that the human soleus muscle shrinks by a third after only 3 weeks in space. This is followed by loss of slow-twitch muscle fibres which are essential for endurance. For safe operation of astronauts in Mars where the gravity is only 40% of that of Earth, mitigating strategies are needed to avoid muscle deconditioning.
Dr Mortreux added that diet is the key as astronauts on Mars would not have access to exercise machines which are present in ISS. Resveratrol has been found as a suitable candidate which is mainly found in grape skin and blueberries. It helped in preserving the bone and muscle mass in rats during conditions such as complete unloading, similar to microgravity during spaceflight. Thus scientists view that a moderate daily dose would help to prevent muscle deconditioning in Mars gravity.
For replicating Mars gravity, scientists used a method which was developed in mice by Mary Bouxsein, where rats were fitted with a full-body harness and suspended from their cage ceiling by a chain. Thus, 24 male rats were exposed to normal loading (Earth) or 40% loading (Mars) for 14 days. In each group, half received resveratrol (150 mg/kg/day) in water; the others got just the water. Otherwise, they fed freely from the same chow.
Circumference of calf and front and rear paw grip force were measured every week, and after 14 days, the calf muscles were analysed.
As it was expected, the Mars condition led to the weakening of the rat’s grip and their calf circumference shrank along with muscle weight and slow-twitch fibre content. However, resveratrol rescued the front and rear paw grip almost entirely in the Mars rats similar to the level of Earth rats who were non-supplemented. It also protected the muscle mass entirely and decreased the loss of slow-twitch muscle fibres. However, it could not rescue the soleus and cross-sectional area of gastrocnemius fibres or calm circumference. It did not affect total body weight.
Dr Mortreux said that resveratrol treatment increases the muscle growth in diabetic or unloaded animals with an increase in insulin sensitivity and glucose uptake in muscle fibres. This is relevant for astronauts who develop reduced insulin sensitivity in spaceflights. Anti-inflammatory effects of resveratrol would also conserve the muscle and bone. Anti-oxidants such as dried plums are used to test this. It is also essential to confirm if resveratrol develops any harmful interactions with the drugs which are administered to the astronauts in spaceflights. Studies are also needed to find out the effects of different doses of resveratrol in males and females.
Journal Reference: Frontiers in Physiology