Over the past 30 years, a large and varied body of research has examined the role of chronic psychosocial stress in the development of cardiovascular disease (CVD). The mechanisms behind this association are not fully understood, but several studies support the link between increased stress levels and inflammation. Further, that inflammation is directly involved in the atherosclerotic process in the arteries. Many of the brain areas involved in emotions are also involved in sensing and regulating levels of inflammation in the body. In 2014 a group of researchers at the University in Pittsburg studied 157 healthy adult volunteers who were asked to regulate their emotional reactions to unpleasant pictures while their brain activity was measured with functional imaging. They found that individuals who showed greater brain activation when regulating their negative emotions also exhibited elevated blood levels of interleukin-6, one of the body’s pro-inflammatory cytokines that regulates the immune system and plays a role in cognitive function. Further they observed an increased thickness of the carotid artery wall, a marker of atherosclerosis. The results were independent of age, sex, race, smoking status, and other known CVD risk factors.
Last week Lancet published results from an American study of 293 mentally healthy participants without cardiovascular disease who underwent clinical measurements and scan of the brain. The participants where then followed for four years. The researchers from Harvard Medical School wanted to assess if activity in amygdala, a part of the brain that is involved in emotional processing, could predict cardiovascular events. And they did. The results showed that high activity in amygdala was independently associated with cardiovascular events, and that 39% of this association was explained by arterial inflammation. They also found that most of the association between perceived stress (measured by questionnaires) and arterial inflammation was explained by amygdala activity. Another interesting finding was that bone marrow activity explained 46% of the association between amygdala activity and arterial inflammation. Activation of the bone marrow leads to release of inflammatory cells taking part in in the atherosclerotic process.
In turn, the results from this study reveals an important piece of the puzzle on how psychosocial stress gets under the skin. It also reminds us of the importance of coping with stress in our daily life. Some important behaviors that help our bodies to keep up this balance are regular exercise, getting enough sleep and eating healthy foods. Practicing mindfulness, mediation and yoga have also shown to have positive effect on perceived stress levels. And last but not least, do not forget to laugh. Laughter also adds year to your lifespan.
Linda Ernstsen, Associate Professor CERG