Is moon trip safe for heart?

Only 24 people have ever gone to deep space, or to the area beyond the Earth’s magnetic shield. These are the Apollo astronauts who flew to the moon, the last of whom did so in 1972.

Today, dreams of deep space exploration are surfacing again.

Michael Delp, a professor of human sciences at Florida State University, said researchers need to better understand and study the effects of deep space travel.

In a paper published Thursday, a week after the 47th anniversary of the first moon landing, Delp and a NASA-affiliated team of researchers examined how deep space travel may have affected the cardiovascular health of Apollo astronauts.

Comparing Apollo astronauts who have died with other astronauts who either never flew in orbital missions or only flew in low Earth orbit, Delp and his colleagues found a higher rate of cardiovascular deaths among Apollo astronauts. Based on further research in mice, they suggest the cause of cardiovascular disease in these astronauts may have been deep space radiation.

Experts have concerns about the scientific legitimacy. To date, only seven of the 24 Apollo lunar astronauts have died. Of those seven, three died of cardiovascular disease.

The problem with a small sample size is that a one-person difference can drastically alter the statistics, said Jay Buckey, a professor of medicine and engineering at Dartmouth College.

Unexplored risk factors could also explain why at least two of the Apollo astronauts died of cardiovascular disease, Buckey said. “Were they smokers? Did they have a family history of heart disease? Did they have high cholesterol? Those are all factors that could lead to heart disease, without having to bring galactic cosmic radiation into the mix,” he said.