As we embark on a new era of space travel, a recent study sheds light on an intriguing aspect of the human body's response to the extraterrestrial environment.
Published in Scientific Reports, the study focuses on the space travel impact on the human brain. Researchers from the University of Florida examined brain scans of 30 astronauts before and after their stays in space.
They found the brain’s ventricles expanded significantly in those who completed longer missions of at least six months. It also found that fewer than three years may not provide enough time for these ventricles to recover fully.
“We found that the more time people spent in space, the larger their ventricles became,” said Rachael Seidler, a professor of applied physiology and kinesiology at the University of Florida and an author of the study. “Many astronauts travel to space more than one time, and our study shows it takes about three years between flights for the ventricles to fully recover.”
The cerebrospinal fluid in the brain's ventricles protects, nourishes and removes waste from the brain. The human body has efficient mechanisms for distributing fluids to all parts, but in zero gravity, fluid transfers upward, elevating the brain within the skull and increasing the size of the ventricles.
The study examined astronauts with varying mission durations. Some embarked on two-week missions, while others spent six months or approximately one year in space. The researchers noted that the expansion of the ventricles reached its peak after six months, with no further substantial changes observed beyond that point. That revelation offers hope for the future as longer-duration missions become increasingly viable.
“We were happy to see that the changes don’t increase exponentially, considering we will eventually have people in space for longer periods,” Seidler said.
With longer-duration space missions on the horizon, understanding the effects of extended periods in space on human physiology is crucial. While ventricular expansion appears to be the most enduring change observed in the brain resulting from spaceflight, the long-term consequences remain uncertain.
While the precise implications of ventricular expansion on space travelers' health and behavioral well-being are yet to be fully elucidated, it is prudent to prioritize restoring the brain's physiological balance.
A hiatus of at least three years after longer missions is a wise course of action, according to the researchers. This may be enough time for the ventricles to return to their normal state.
“We don’t yet know for sure what the long-term consequences of this is on the health and behavioral health of space travelers,” Seidler noted, “so allowing the brain time to recover seems like a good idea.”
As the allure of space tourism continues to grow, this study does bring some encouraging news. Seidler says shorter trips appear to cause minimal physiological changes to the brain, allowing individuals to enjoy brief excursions without significant long-term consequences.
Nonetheless, the study's authors caution that extended periods in space demand careful consideration and ongoing research.