Using fatty foods to comfort eat during times of stress can harm the body's recovery from the pressure, research suggests.

Although many people turn to unhealthy foods such as chocolate, crisps or pastries when they are feeling the strain, researchers have found this can reduce blood flow to the brain and cause poorer vascular (血管的) function, which in turn can have a negative effect on mental health and increase the risk of heart disease. The researchers suggest people resist the attraction of convenient treats by eating fruits and vegetables instead.

Prof Jet Veldhuijzen van Zanten said, "We looked at healthy 18- to 30-year-olds for this study, and to see such a clear difference in how their bodies recover from stress when they eat fatty foods is staggering." For people who already have an increased risk of cardiovascular (心血管) disease, the impacts could be even more serious. We all deal with stress all the time, but especially for those of us in high-stress jobs and at risk of cardiovascular disease, these findings should be taken seriously. This research can help us make decisions that reduce risks rather than make them worse.

The study involved a group of young healthy adults who were given two butter bread as breakfast. The participants were then asked to do mental maths, increasing in speed for eight minutes, and alerted when they got an answer wrong. They could also see themselves on a screen.

The researchers found that consuming fatty foods when mentally stressed reduced vascular function by 

1.74%. Previous studies have shown that a 1% reduction in vascular function leads to a 13% increase in cardiovascular disease risk.

"We also know that the elasticity (弹性) of our blood tubes, which is a measure of vascular function, declines following mental stress," said the study's first author, Rosalind Baynham from the University of Birmingham.