Calcium in arteries? Hard to figure

According to many cardiologists, calcium in the coronary arteries (detected on scanning, often as a screening test for heart disease) is a major risk factor for heart attacks and premature death, so if you have calcium in your cardiac arteries, you need to do something about it, which in the US at least, far too often involves some type of (costly) intervention by a cardiologist.

But in some people at least, calcium in cardiac arteries does not seem to be linked to an earlier death from heart disease according to this recent study published in JAMA Cardiology.

In this ongoing study of over 21,000 healthy men (it’s known as the Cooper Center Longitudinal Study; worth looking up for some insights about chronic disease over time), men who said they were participating in the highest level of aerobic activity actually had higher levels of coronary calcium build-up than men who did the least aerobic activity.

No one is sure why, of course: perhaps too much exercise leads to calcium build-up, or perhaps men who know they are are much higher risk of heart disease end up doing a ton of exercise to mitigate that effect (although I really doubt that).

Whatever the link is, the most important finding in this study, I think, was that despite what the experts believe should have happened if calcium build-up is such a bad thing, the guys with the most calcium build-up were actually no more likely to die prematurely than other men in the study (very very unsurprisingly the men who did the least exercise were more likely to die prematurely than those who did some level of exercise).

So if coronary calcium is such a major risk factor, why did exercising men who had high levels of calcium build-up not die early?

Most likely it’s because exercise protects against heart attacks even in men who are presumably at highest risk of such an event although it’s also very likely that anyone who does a lot of exercise also follows many of the other recommendations to improve heart health such as eating a good diet, not smoking, etc., and that’s what protects them against premature death.