Psychosocial stress occurs on a daily basis in relation to workload and our 24/7 lives, both of which have increased over the past 10 years. The consequences seen are often associated with psychological disorders like depression, but such stress is also associated with a substantially higher number of heart attacks.
But does this mean causality? In animals, the link has been established between stress and arterial disease (acting through increased blood inflammation and as a result arteriosclerosis), but direct clinical evidence in human beings has been lacking. Not so much anymore. A study in the Lancet led by a team from Harvard reports on the activity of the amygdala, an area activated by stress. What do the cells in this almond-sized area of the brain do? They prepare us for fight or flight. The amygdala is activated by strong emotional stimuli such as fear and pleasure. But what happens in the absence of these stimuli? Are people with higher activity in the amygdala during a resting state more likely to develop cardiovascular disease? In that study of almost 300 people, the subjects underwent scans of the brain, bone marrow, spleen, and arteries. With these scans, the researchers identified 22 people who had higher activity in the amygdala. These subjects also had more white blood cell production and arterial inflammation and, within four years, developed cardiovascular disease.
A separate study of 13 post traumatic stress disorder patients found a correlation between higher perceived stress levels and higher amygdala activity, and again more inflammation of arteries. This raises the possibility that reducing stress could produce benefits that extend beyond an improved sense of well-being to include benefiting our cardiovascular health. Which brings us to mindfulness. With just eight weeks of meditation, a reduction in stress correlates positively with decreases in grey matter density in the amygdala. So, could more mindfulness be a way of improving our cardiovascular health? It’s beginning to look that way.