Life in Space Can Make Your Body Age Faster

Thanks to time dilation, astronauts who spend a long time on the International Space Station actually age less than their counterparts on the ground—granted only by about 0.007 seconds every six months, but it’s still a manifestation of a pretty weird quirk of constantly traveling at over 17,000-miles per hour.

Thing is, even if they’ve technically aged less, the bodies of astronauts are taking a toll from being in the microgravity of space. A new study, published in November’s FASEB Journal, found that the effects of floating around wear on the body like a long life on Earth does, changing how genes express themselves.

According to the researchers from Institute of Molecular Science and Technologies in Milan, living in microgravity “generates alterations that are similar to those involved in age-related diseases, such as cardiovascular deconditioning, bone loss, muscle atrophy, and immune response impairment.”

The research is the latest in growing body of evidence of how outer space wears on the human body. Coming back to Earth involves rehabilitation, to build up muscles that weakened from underuse and accomondate the lost bone mass. Being in space is no treat for a number of physical reasons—the lack of gravity allows fluids that are normally held down in the body by gravity to crowd the sinuses. The fluids can also cause uncomfortable pressure behind the eyes and even impair vision to the point of "space blindness." Inversely, relaxed abdonimal muscles that are free from Earth's gravity can lead to a lot of space farting too.

This latest study looked at endothelial cells, which line the interior of blood vessels, aboard the International Space Station, conducting deep gene expression and protein analysis on them and comparing them to cells on the ground. Just as in the aging process, the cells demonstrated endothelial dysfunction, as the microgravity environment lead to over a thousand “significantly modulated genes.” Endothelial dysfunction can lead to coronary artery disease and hypertension, hardly issues you'd want the first person on Mars to have to deal with. The microgravity lead to inflammation among the cells, which led to atherosclerosis and cell senescence, or biological aging.

"We've evolved to rely on gravity to regulate our biology, and without it, our tissues become confused," FASEB Journal editor Gerald Weissmann said. "Worst of all: they age faster!"

If people are going to make trips deeper into space and travel for longer periods of time—traveling to Mars or beyond—then we’ll need to figure out what being away from Earth does to us. After all, our bodies evolved in response to life on Earth; so we’ll have to pack whatever we need once we’re away from what the planet requires and provides. It certainly serves my suspicion that riding on the Spaceship Earth remains the grooviest option for speeding across the universe.