A new study found white men who exercise more than seven hours a week have an 86% higher risk of developing plaque build-up in their arteries. No such elevated risk was seen among either black men or women.
Plaque build-up is a critical warning sign for possible future heart disease risk.
“We were surprised by the finding, mainly because we essentially think of exercise as medicine. And we’ve never thought of exercise as perhaps having an upper limit in terms of its cardiovascular benefit,” said study author Deepika Laddu.
She’s an assistant professor of physical therapy at the College of Applied Health Sciences at the University of Illinois at Chicago.
“What we saw is only an association, and we cannot say that high physical activity actually causes plaque build-up in white men,” she noted. “And we certainly do not mean to say that exercise is bad for you. In fact, it could perhaps be that white men already face a higher than average risk for plaque build-up than other men, and that exercise prevents this plaque from rupturing, which is when thing get bad. We just don’t know,” Laddu explained. “Much more research will be needed to understand what is really going on.”
At least one other expert agreed this doesn’t mean people should stop exercising. Dr. Gregg Fonarow, a professor of cardiology at the University of California, Las Angeles, said “it should be recognized that exercise alone cannot overcome other cardiovascular risk factors.” He added, “and it is vital to maintain health levels of blood pressure, cholesterol and body weight, as well as not smoke, even if one is engaging in regular rigorous physical activity.”
To explore how exercise might impact heart health over time, the investigators recruited nearly 3,200 white and black men and women. All enrolled when they were between the ages of 18 and 30, and all resided in one of four cities: Birmingham, Chicago, Minneapolis or Oakland.
The researchers followed the study volunteers from 1985 to 2011. During that time, participants self-reported their physical activity routines and showed up for at least three follow-up exams, which included CT scans to measure plaque build-up.
Current U.S. physical activity guidelines recommend 150 minutes of moderate activity or 75 minutes of vigorous activity weekly. Participants were sorted into three groups, depending on average exercise levels. One group exercise below the guideline level. Another group met the guidelines and a final group exercised three times more than the guideline level.
The study team found that overall those who were among the most frequent exercisers were 27% more likely to develop plaque build-up by the time they had reached middle age. But after breaking the numbers down further, the authors determined that only high–exercising white men faced a greater risk.
The study was published Oct. 16 in the Mayo Clinic Proceedings.
As a white man who exercises frequently I am this demographic. My first cardiologist explained that my abnormal EKG was a result of long term aerobic exercise. However, she told me that the enlargement of the left ventricle was actually a good thing.
Twenty years later we now know that left ventricular hypertrophy is associated with Afib and maybe isn’t such a good thing. The key to controlling Afib is to continue the exercise, just avoid the high intensity workouts. I train much like a triathlete, but I don’t compete.
I suspect that long term exercise does create a little more plaque in the arteries as a result of vascular damage. After all, more blood coursing through the arteries under more pressure, more frequently will be more stress. However, a little plaque will strengthen the artery wall – that’s the intended mechanism. It’s only when plaque is excessive and “vulnerable” plaque forms that the risk for CVA increases.
Finally, more and more studies are using high-speed CT scans to evaluate various risk factors for heart disease. The test is readily available to the public and is a fraction of the cost of a cardiac stress test. It will detect heart disease ten years earlier than the stress test. However, the test is seldom ordered and has never been accepted as the gold standard in cardiology.
The Bottom Line:
I’m going to stick with my exercise regimen and I recommend you do likewise. This is a preliminary study and we have very little understanding of what the data really means. I look forward to reading future studies in this area.
Source: October 18, 2017 National Institutes of Health