Space travel exposes astronauts to unusual forms of radiation on Earth, and those related to cancer and heart problems, but a study in the US showed that this did not significantly shorten their lives.
The researchers compared nearly 60 years of data from US male astronauts and a group of men who were both extra-fit, rich and received elite health care – pro athletes. They found that no group had a higher death rate than the others as a whole or premature death. However, both groups tend to last longer than others.
Astronauts are generally well educated, more prosperous and physically healthier than Americans in general, and some previous studies have linked this career with a lower risk of early death, said the study team in Occupational & Environmental Medicine.
But many previous studies on mortality rates for astronauts have not taken into account the mental and physical demands of these careers, or what are called "healthy worker effects" that make people with any job usually have fewer medical problems than individuals who cannot work, said colleagues Study author Robert Reynolds of Mortality Research & Consulting, Inc. at the City of Industry in California.
"The challenge is always to understand whether astronauts are as healthy as they are if they are employed comparatively but never go into space at all," Reynolds said via email. "To do this, we need to find groups that are comparable to several important factors, but have never been to space.
The researchers compared the mortality rates for US male astronauts with professional athletes from Major League Baseball (MLB) and National Basketball Association (NBA) between 1960 and mid 2018.
Both athletes and astronauts have a lower risk of premature death than the general population, the study found. And there is no significant difference in mortality between NBA and MLB players.
We cannot confirm from the data we have, but we speculate that cardiovascular fitness in particular is the most important factor in the longevity of astronauts.– Robert Reynolds
Astronauts are more likely to die from accidents and other external causes, and are less likely to die of heart disease and all other natural causes.
"We cannot confirm from the data we have, but we speculate that cardiovascular fitness in particular is the most important factor in the longevity of astronauts," Reynolds said.
More radiation on the Mars mission
The results showed that radiation exposure in space might not cause premature death for astronauts due to certain heart or cancer problems, the study authors concluded. In fact, astronauts have lower death rates due to heart disease than NBA and MLB players, and have cancer deaths similar to those of athletes.
This study is not designed to prove whether or how space travel can have a direct impact on human health. It also does not examine deaths among female astronauts or athletes.
Radiation exposure may also be much lower during the initial mission to the moon and does not reflect what will happen to the current generation of astronauts, said Francis Cucinotta, a researcher at the University of Nevada, Las Vegas, who was not involved in the study. .
"The mission in the past was low dose, while in the future the dose will be 50 to 100 times higher for Mars missions," Cucinotta said via email.
Astronauts usually never smoke, which causes a lower risk of heart disease than the general population, Cucinotta said.
Diet and exercise also make astronauts and professional athletes different from other populations, said Michael Delp, a researcher at Florida State University in Tallahassee who was not involved in the study.
"When physical fitness is part of the job, such as with astronauts and professional athletes, this is a major determinant of the effects of healthy workers," Delp said via email.
Even for all of us, "staying or being physically active and maintaining a balanced diet greatly improves overall health and well-being, and can improve the success of aging," advises Delp.