Why Stress Makes You More Likely to Have a Heart Attack

Stress might seem like an unavoidable reality of modern life, but your body isn’t as quick to write it off as such: in fact, being stressed takes a serious—and lasting—toll on your life, and according to a growing number of studies, it also increases your risk of heart disease.

Now, according to a new years-long study published in The Lancet, scientists report that having a more active amygdala—the brain region triggered during moments of stress—is linked to a higher risk for heart disease and stroke.

In the study, 293 people without heart problems were given a PET/CT scan to measure brain activity, bone marrow activity and inflammation of the arteries. These three areas interact in important ways in animal models, says study author and cardiologist Dr. Ahmed Tawakol, co-director of the Cardiac MR PET CT Program at Massachusetts General Hospital. Stress, it seems, triggers the amygdala, which then activates bone marrow and inflammation of arteries.

Scientists don’t yet know whether the same is true for humans. But if it were, then people with the most active amygdalas would be the ones with the highest risk of heart attack and strokes. That’s exactly what Tawakol and his team found almost four years later when they followed up. In people with more active amygdalas, these bad heart events also seemed to happen sooner. They also had increased bone marrow activity and inflammation in the arteries.

You may not even need a brain scan to find out your true stress levels. In a small separate study, the researchers asked 13 people with higher-than-usual stress to rate how stressed they generally felt using a psychological questionnaire. “We found that their perception of stress nicely related to activity in their amygdala,” Tawakol says. Those who said they were the most stressed really had the most active amygdalae. The researchers also found that a person’s perceived stress was related to their levels of inflammation.

The study is purely observational and needs to be substantiated in larger trials. But this intriguing new pathway for how stress may take a toll on the heart presents a powerful case for stress relief. “So far, it appears that things like mindfulness and other stress reduction approaches seem to really nicely tamp down on the amygdala, and they appear to even cause benefits in other areas of the brain,” says Tawakol.

“When I talk to my patients, I tell them that we’re learning that diet, exercise, and stress reduction are some of our most compelling tools—it’s a little humbling,” he adds. “Even though it’s unsexy and doesn’t really show the best technology that we have to offer our patients, at the end it is probably the best advice.”