Study: ​Astronauts at Greater Risk for Heart Disease

Astronauts face a higher risk of heart disease when compared to the general population, according to a new study conducted published in the journal Scientific Reports.

Deep-space travel is often referred to as the last frontier. While more than dozen astronauts have successfully ventured outside of the Earth's protective magnetosphere -- and returned -- there's still much we don't know about the effects of deep-space travel. How does it affect the cardiovascular system? Does deep-space travel have any lasting affects on a person's health? What does it do to their mental health? These are all questions that scientists are trying to answer so we can better protect our astronauts.

According to the study, Apollo astronauts are dying at a higher rate from heart disease than their counterparts. For the study, researchers compared health data on 42 astronauts who had previously traveled into space. Seven of the participating astronauts had traveled to the moon -- beyond the Earth's magnetosphere. Researchers were shocked to discovered that the rate of cardiovascular disease for these seven astronauts was 43%. To put that number into perspective, the average rate of cardiovascular disease for the general public is around 9-11%.

So, what's causing these astronauts to develop cardiovascular disease at such a high rate? Researchers speculate that the correlation between deep space travel and heart disease could be attributed to the large amounts of radiation to which astronauts are exposed outside the Earth's magnetosphere.

The Earth has an invisible shield protecting it from solar and deep-space radiation. Known as the magnetosphere, it literally repels radiation, blocking out a signification portion of radiation and preventing it from reaching ground. But astronauts who travel beyond this invisible shield don't receive this protection; thus, they are more susceptible to its effects.

To further investigate the link between deep space travel and heart disease, researchers conducted a test using mice. They found that mice exposed to similar amounts of radiation as deep space astronauts were more likely to die from heart disease-related illness and complications.

"These data suggest that human travel into deep space may be more hazardous to cardiovascular health than previously estimated," wrote the study's authors.