We’ve long known that stress is a risk factor for heart disease. But scientists still have little understanding of how it contributes to cardiac events like heart attack and stroke. At the American College of Cardiology’s 65th Annual Scientific Session, researchers from Massachusetts General Hospital shared their findings that individuals with heightened activation of the amygdala—the stress center of the brain—are more likely to have arterial inflammation, and are at increased risk for cardiac events like stroke, heart attack, and premature death. Mindfulness practices like yoga, meditation, and tai chi may help to alleviate these effects and promote heart health.
The Mass General study was the first in which neuroimaging data (brain scans) were examined to explore the link between brain activity and arterial inflammation. Arterial inflammation is a leading cause of atherosclerosis—a disease in which plaque accumulates inside arterial walls, eventually constricting or prohibiting blood flow. It can occur in any artery in the body and is a major predictor of disease.
The researchers reviewed the PET/CT scans of 293 adults aged 30 years or older (mean age of 55 years) who had no existing cancer or cardiovascular disease. Scans provided objective measures of activity within the brain, arteries, and bone marrow.
One hour prior to the scan, participants were injected with a radioactive tracer that served as a marker of increased metabolic activity. Researchers then compared activity in a participant’s amygdala to activity in other regions of their brain to obtain a rating of stress-related brain function. Higher relative levels of amygdala activity were associated with increased stress. Based on these ratings, each participant was assigned to either a high- or low-stress brain activity category.
Results showed that higher levels of amygdala activity were associated with both greater inflammation and increased bone marrow activity. Bone marrow releases immune cells called monocytes that are directly related to systemic inflammation. What’s more, individuals in the high-stress category were considerably more likely to suffer a cardiac event during the following five years (35%) than those in the low-stress category (5%).
These findings point to the importance of directly treating stress to decrease atherosclerotic inflammation and reduce heart disease risk.
Emerging evidence suggests that mindfulness practices such as meditation, breath modification, yoga, and tai chi may provide a safe and effective non-pharmaceutical option for treating stress and increasing emotional resilience.
For example, participants in another study experienced reductions in amygdala cell volume and greater emotion regulation after eight weeks of regular meditation. This raises the possibility that mindfulness practices like meditation and yoga may help to enhance cardiac resilience.
Indeed, a 2015 review of randomized, controlled trials on the effects of yoga on measures of stress found consistent evidence that regular yoga practice is linked to parasympathetic nervous system (the rest, digest, and repair nervous system) activation and hormonal changes related to stress reduction.
We know that stress undermines heart health. Much more research is needed to fully clarify the mechanisms through which stress-related brain changes are related to inflammation and disease, and the ways in which mindfulness practices may mediate this relationship, but it is clear that stress reduction is an essential element for preventing and treating risk factors associated with cardiac disease.
Whether you do yoga to relieve stress or to prevent it, the evidence suggests that regular yoga practice is good for you. Consult your physician and a qualified yoga teacher to make sure that you choose a style of yoga that is best suited to your strengths and needs.
Ishai, A. & Tawakol, A. (2016). “Greater Activity of the Brain’s Emotional Stress Center Associates With Arterial Inflammation and Predicts Subsequent CVD Events,” Presented at the American College of Cardiology’s 65th Annual Scientific Session in Chicago.