Story at a glance
- The rising interest in commercial space travel, in addition to recent high-profile NASA projects, raise questions about the long-term safety of space exploration.
- To better understand how spaceflight affects individuals, researchers assessed blood samples from 14 healthy astronauts.
- A total of 34 mutations in 17 genes were identified, which may indicate these individuals have an increased risk of some cancers and cardiovascular disease.
The rise of the space tourism industry, along with NASA’s recently postponed Artemis I project, have helped bring space exploration back to the forefront of the national conversation.
But recent research published in Communications Biology highlights the potential health risks astronauts might face upon their return to Earth.
A team of researchers from the Icahn School of Medicine at Mount Sinai assessed blood samples from 14 astronauts who flew short missions between 1998 and 2001.
Data revealed spaceflights may be associated with DNA mutations that can raise the risk of developing cancer and heart disease throughout individuals’ lifetimes.
The study is the first of its kind and included analyses of astronauts’ blood taken 10 days prior to flight, the day of landing, and three days after landing.
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Median participant age at the time of the flight was 42 and the majority were male. For six individuals, the mission was their first. The median length of all missions was 12 days, and blood samples were stored for around 20 years before analyses.
“Spaceflights are associated with exposure to various stressors, including [space radiation], microgravity, and other harmful space environmental factors,” authors wrote, while the mutations identified in the study are typically caused by environmental factors, like exposure to ultraviolet radiation.
Hematopoietic stem cells — or those that can develop into white blood cells, red blood cells or platelets — from all 14 astronauts revealed DNA mutations, known as somatic mutations, which cannot be passed onto offspring.
The mutations were found in clonal hematopoiesis (CH)-driver genes. CH is a process in which blood cells derived from a single clone are overrepresented, and marks a relatively benign precursor state that can develop into CH of indeterminate potential (CHIP).
Although CH is not an indicator of disease, it is associated with an increased risk for both cancer and cardiovascular disease, researchers explained, adding the findings underscore the importance of blood screening for working astronauts and those in retirement.
“Astronauts work in an extreme environment where many factors can result in somatic mutations, most importantly space radiation, which means there is a risk that these mutations could develop into [CH],” said lead study author David Goukassian of the Cardiovascular Research Institute at Icahn Mount Sinai in a statement.
“Although the [CH] we observed was of a relatively small size, the fact that we observed these mutations was surprising given the relatively young age and health of these astronauts,” said Goukassian.
Researchers identified a total of 34 mutations in 17 CH-driver genes. The results do not mean astronauts will develop the diseases, but over time, risks may increase thanks to prolonged exposure to the deep space environment.
“Our recommendation is that NASA, and its medical team, screen astronauts for somatic mutations and possible clonal expansion, or regression, every three to five years, and, not less importantly, well into their retirement years when somatic mutations may expand clonally and become CHIP,” Goukassian added.
Additional longitudinal studies are needed to better understand the health risks of spaceflight and target interventions in those who might be at greatest risk of poor health outcomes, authors concluded.
Published on Aug 31,2022