(NewsNation) -- Traveling to space can take a toll on the human body, and new research shows it can also speed up the aging of blood and immune cells.
In the study published in the journal Cell Stem Cell, researchers at the University of California, San Diego collected stem cells from bone marrow donated by people who underwent hip replacement surgery and put them inside "nanobioreactors," or small, transparent blood bags. Each sample was divided into two cell monitoring boxes, one going to space and the other staying on Earth.
Over the 32-45 days the stem cells spent in space, the fitness and function of the cells got worse and showed several signs of aging, such as diminished ability to rest and regenerate; increased signs of DNA damage, and shorter telomeres, which are the protective caps at the ends of chromosomes. The shortening of telomeres can contribute to an increased cancer risk.
"Space is the ultimate stress test for the human body," Dr. Catriona Jamieson, director of the Sanford Stem Cell Institute at UC San Diego, said. "These findings are critically important because they show that the stressors of space -- like microgravity and cosmic galactic radiation -- can accelerate the molecular aging of blood stem cells."
The new findings build upon NASA's recent Twins Study, which looked at the effects of spaceflight on gene expression. It was accomplished by comparing retired astronauts and identical twins Scott Kelly, who went to space, and Mark Kelly, who remained on Earth.
Researchers did find that once the cells made it back to Earth, some of the damage began to reverse, which suggests that it may be possible to develop preventative treatments to protect or even rejuvenate these cells, which they said is a key focus of future research.