Remember that time your neighbor cut down your favorite tree? Or when your boss took the credit for that project you worked so hard on?
If you can already feel the bile rising, you might want to take a deep breath. A new study by a team of researchers from the US has shown how the lining of blood vessels become stressed even with brief provocations of anger.
Since this kind of stress has previously been linked to an increased risk of heart disease and stroke in patients with coronary heart disease, outbursts could literally put some people's lives at risk.
Earlier studies had identified a potential link between anger and cardiovascular health, but the reasons for that relationship weren't clear. What this study shows is that when we stay relaxed, our blood vessels stay relaxed too.
The team behind the research found that feelings of anxiety and sadness didn't trigger changes in the lining of blood vessels in the same way – even though these emotions have also been associated with heart problems in other studies.
"We saw that evoking an angered state led to blood vessel dysfunction, though we don't yet understand what may cause these changes," says Daichi Shimbo, a professor of medicine at Columbia University.
A group of 280 healthy participants were randomly assigned to one of three tasks and a control activity, each lasting eight minutes. Before and after the task, the cell linings of the volunteers were analyzed via blood samples.
The tasks involved either recalling a personal memory that triggered anger, recalling a personal memory that triggered anxiety, reading a series of depressing sentences to trigger sadness, or repeatedly counting to 100 (to maintain emotional neutrality).
With the anger task (and only the anger task), impairments in blood vessel dilation – a tightening of the blood vessels which impedes blood flow through the body – were noticeable three minutes after the task was completed, but faded away by the 40 minute mark.
While feeling and expressing anger can be beneficial, this research shows it could also be increasing the risk of heart problems by restricting blood flow, especially when the emotion is experienced consistently or chronically in those who already have risk factors for cardiovascular disease. The next step is to look more closely at how the emotion and the biological consequence are linked.
"Investigation into the underlying links between anger and blood vessel dysfunction may help identify effective intervention targets for people at increased risk of cardiovascular events," says Shimbo.
Future research could look at this relationship in older groups of people, and those on medication related to heart issues. As the researchers note, it could also inform approaches to helping people manage their anger.
The study adds to what we already know about the links between our emotions and our bodies – and knowing which feelings trigger which changes in the body can help improve our understanding of mental and physical health. Here, anger leads to blood vessel changes that aren't seen with anxiety and sadness.
"Therefore, all negative emotions should not be grouped together as the same when looking through the lens of cardiovascular disease pathophysiology," write the researchers in their published paper.
The research has been published in the Journal of the American Heart Association.