A new study into how spaceflight impacts the human brain and eyes revealed notable sex differences in brain fluid shifts, with female astronauts showing a greater reduction in fluid around the uppermost part of the brain than their male counterparts.

Led by Rachael D. Seidler, Ph.D., director of the University of Florida’s Astraeus Space Institute and professor of applied physiology and kinesiology, the study analyzed data from astronauts to determine how factors such as sex, age and body metrics relate to structural brain and eye changes after space travel.

The findings, published in npj Microgravity, provide key information for protecting astronaut health on long-duration missions to the moon and Mars.