Four years after finding that veteran marathon runners tend to have more unhealthy plaque in their arteries than non-runners, Minneapolis cardiologist Robert Schwartz finally found a medical journal willing to publish his controversial conclusion.
Rejected by journal after journal, Schwartz and co-authors were accepted by Missouri Medicine — an unexpected outlet for a Minnesota researcher — which was publishing a special issue on running and medical research.
“I think it is the controversy being engendered by this,” said Schwartz, who has published more than 100 papers.
This study had limitations: It reviewed only 50 marathoners who had completed 25 marathons, and compared them with a control group of 25 cardiology patients. (Co-author Dr. William Roberts is medical director of the Twin Cities Marathon and helped find runners for the study.)
But the result was clear: While the marathoners were in superior health overall, they did have more plaque buildup, which puts them at risk for heart attacks and other disorders.
The theory is that extreme running elevates your blood pressure and causes other stress inside blood vessels that leads to injury and plaque formation. “It suggests there is in fact a dose effect,” Schwartz said, “that too much of a good thing is possible here.”
If additional studies confirm the results, Schwartz said, extreme runners could take precautions such as daily aspirin to reduce their risks.
The authors started their research believing they would contradict similar findings in 2008 by German researchers. They were surprised.
One subject in their study hadn’t missed a day of running in two years and was two days from his next marathon when a scan found a vessel blockage and an imminent risk of heart trouble. “Something potentially dangerous could have happened,” Schwartz said, “had he run the race.”