Spaceflight Could Increase Risk Of Cancer And Heart Disease In Astronauts, Study Suggests

A team of researchers from the Icahn School of Medicine at Mount Sinai studied blood samples taken from 14 NASA astronauts before and after they took part in relatively short spaceflight missions (with a median of 12 days) between 1998 and 2001.

They discovered that all 14 astronauts’ blood had DNA mutations known as somatic mutations, specifically those characterized by the overrepresentation of blood cells derived from a single clone in a process called clonal hematopoiesis, which is most often caused by environmental factors like exposure to ultraviolet radiation.

While clonal hematopoiesis doesn’t necessarily indicate the presence of disease, it is associated with a higher risk of blood cancer and cardiovascular disease and can evolve into the more serious clonal hematopoiesis of indeterminate potential, or CHIP, according to the study.

Researchers said the clonal hematopoiesis they observed was relatively small in size, but they were surprised by the findings, especially considering the astronauts’ relatively young age—their median age was 42 years old—and good health at the times of their spaceflights.

The presence of the mutations does not mean the astronauts will develop cancer or heart disease, but the study’s lead author David Goukassian, a professor at Icahn Mount Sinai, said in a statement that the risk could increase from “ongoing and prolonged exposure to the extreme environment of deep space.”

The researchers recommended that NASA screen astronauts for somatic mutations and clonal expansion every three to fives years well into old age—when developing CHIP is more common—and called for larger studies to be done on the long term effects of spaceflight on the human body.