Over the years, the link between heart disease and emotional stress has been discussed. The link is clear, but experts had no idea of exactly how those two conditions are linked. A recent study, originally published in the Lancet, has provided new insight regarding brain activity within the amygdala and heart disease. We are all walking around with two of these amygdalae — which means “almonds” in latin, so called because they resemble almonds in shape and size. They are in deep inside the brain on both sides more or less where your ear sits and they process emotions, particularly stress and fear.
The study conducted in the Lancet checked if a lot of activity in the amygdala can predict the risk of heart disease. The authors recruited 293 participants with an average age of 55. They were all healthy at the start of the study. The researchers followed them up over more than 3 and a half years and scanned their brain to look at the activity in their amygdalae. They also recorded spleen activity and other things that are linked with inflammation of their blood vessels. During the 3.5 of the study, 22 participants had a “cardiovascular disease event” — a heart or blood vessel problem of some description. All 22 participants who experienced a cardiovascular event were shown to have an overactive amygdala compared to those who did not have any heart or circulation problems.
According to the researchers excessive activity in the amygdala affects bone marrow activity. The amygdala initially ‘tells’ the bone marrow to make more white blood cells, which are useful when the body needs to fight infection or repair damage. This is partly because the amygdala is what triggers human fight or flight responses, it prepares the human body for danger. When stress is there on an everyday basis, the bone marrow can end up making too many white blood, which in turn, can lead to inflammation or abnormal clotting that can close up blood vessels leading to heart and circulation problems.Increased.
A second Lancet study reports on 13 participants who each had an evaluation for their level of stress. The study looked at whether stress levels are linked with arterial inflammation. Out of the 13 participants those with the highest perceived stress had the greatest amygdala activity and the greatest increase in risk of blood vessel inflammation.
Within a linked comment, Dr Izle Bot said “In the past decade, more and more individuals experience psychosocial stress on a daily basis. Heavy workloads, job insecurity, or living in poverty are circumstances that can result in chronically increased stress, which in turn can lead to chronic psychological disorders such as depression. Besides the heavy psychological burden, chronic stress is also associated with an increased risk of cardiovascular disease.”
By finding ways to manage stress more effectively we can reduce our risk of heart problems. That is why it does not make sense to talk about physical wellbeing and mental wellbeing as if they were totally separate. As science advances we discover they are deeply linked.
Takawol A, Ishai A, Takx RAP, et al. Relation between resting amygdalar activity and cardiovascular events: a longitudinal and cohort study. Lancet 2017; http://dx.doi.org/10.1016/S0140-6736(16)31714-7