Previous research has shown that mental stress immediately increases heart rate and blood pressure in healthy adults, and temporarily impairs the function of arteries.
Single episodes of stress have also been shown to increase the risk of acute cardiovascular events.
In a randomised study, researchers measured forearm blood flow and cardiovascular activity both at rest and during stress.
In assessing the functioning of the blood vessels up to 90 minutes post-stress, they discovered that blood vessel function was less impaired when the participants drank high-flavanol cocoa.
The researchers also discovered that flavanols improve blood flow during stress.
“Flavanols are extremely common in a wide range of fruits and vegetables. Knowing what we do about the cardiovascular benefits of these compounds during periods of acute vascular vulnerability (such as stress), we can offer improved guidance to people as far as their dietary choices during stressful periods,” says lead author Dr Catarina Rendeiro.
“Our findings are significant for everyday diet, given that the daily dosage administered could be achieved by consuming a variety of foods rich in flavanols — particularly apples, black grapes, blackberries, cherries, raspberries, pears, pulses, green tea and unprocessed cocoa.
“This has important implications when it comes to protecting the blood vessels of those individuals who are more vulnerable to the effects of mental stress.”
