The connection is based on a research study. In the study, 293 subjects were examined through brain scans (F-fluorodexoyglucose positron emission tomography). The subjects were monitored over a period of four years, making this a longitudinal cohort study. Of the 293 subjects, 22 went on to develop cardiovascular disease. The scans showed that those with enhanced activity (the 22 subjects) in the region of the brain called the amygdala were more likely than others to develop cardiovascular diseases, including having a higher risk of a heart attack. The study was run at Harvard Medical School.
The amygdalae are two almond-shaped groups of nuclei located deep within the temporal lobes of the brain. This area performs a primary role in the processing of memory, decision-making, and emotional reactions. The amygdala is part of the limbic system, which supports a variety of functions including emotion, behavior, motivation, long-term memory, and olfaction (the sense of smell).
The increased activity in the amygdala is triggered by smoking, high blood pressure and stress. The connection with stress helps to match the medical cases, where emotional stress correlates with cardiovascular disease, with biological responses. The connection with the amygdala tallies since this brain region processes emotions like fear and anger.
The research indicates that high activity in the amygdala signals to the bone marrow to produce extra white blood cells. The proliferation of white blood cells in turn affects the arteries, leading to the becoming inflamed. This physiological change makes the body more prone to heart attacks, angina and strokes. With this connection, the principal scientist Dr Ahmed Tawakol, told the BBC: “Our results provide a unique insight into how stress may lead to cardiovascular disease.”
The researcher added: “This raises the possibility that reducing stress could produce benefits that extend beyond an improved sense of psychological wellbeing.”
The research, despite some reports in the media, is not the first to link stress and cardiovascular disease. Where it is novel is in identifying a brain region. Given the limited size of the study and the one geographical region, the findings remain theoretical. Therefore, although the findings need to be verified through further study, should they be confirmed it is hoped the knowledge will provide a new way of identifying people at risk. After observing the risk of heart disease brought about by that particular area of the brain, help can be provided to people who fall within this group to manage stress.
The study is published in The Lancet, under the heading “Relation between resting amygdalar activity and cardiovascular events: a longitudinal and cohort study.”
