Consuming high-fat foods affects how the body recovers from stress, reduces oxygen supply to the brain, and can also result in poorer vascular function.
A new study by experts at the University of Birmingham examined whether a high-fat diet influences the effects of psychological stress on vascular function. The results are published in the English-language journal “Frontiers in Nutrition and Nutrients”.
How does high-fat food affect stress?
The study had a total of 21 participants. They were instructed to eat either a high-fat (56.5 g fat) or a low-fat (11.4 g fat) meal 1.5 hours before a psychological stress task.
“We took a group of young, healthy adults and gave them two butter croissants for breakfast. We then asked them to calculate for eight minutes, increasing the speed and receiving a notification if an incorrect answer was given,” explains study author Rosalind Baynham in a press release.
Physical reactions to stress
This task should simulate everyday stress that may occur at work or at home. Because “when we are stressed, various things happen in the body: our heart rate and blood pressure increase, our blood vessels expand and blood flow to the brain increases,” reports the doctor.
It is also known that psychological stress can reduce the elasticity of blood vessels, which serves as a measure of vascular function.
Cardiovascular factors and blood lipid levels
The researchers measured the triglyceride concentration in the participants’ blood plasma both before and after the meal. In addition, forearm blood flow, blood pressure and cardiovascular activity were assessed before the meal at rest and after the meal at rest and under stress.
The experts also measured endothelial function using so-called flow-mediated vasodilation before the meal and 30 and 90 minutes after psychological stress.
Impaired vascular function
The data analysis showed that the consumption of fatty foods during mental stress significantly impaired vascular function. If the participants had eaten high-fat croissants beforehand, reduced artery elasticity was still noticeable up to 90 minutes after the end of the stressful test, the team reports.
It is also known from previous research that a reduction in vascular function by just one percent leads to a 13 percent increase in the risk of cardiovascular disease, the experts continued.
Poor oxygen supply
In addition, the researchers found that consumption of high-fat foods reduced cerebral oxygen supply in the prefrontal cortex and caused a 39 percent reduction in oxygen-rich hemoglobin during stress compared to low-fat food.
In addition, consumption of the high-fat food had a negative effect on mood during and after the stress episode.
Significant differences observed
“For this study, we looked at healthy 18- to 30-year-olds and found such a significant difference in how their bodies recover from stress when they eat fatty foods,” reports study author Professor Jet Veldhuijzen van Zanten.
For people at increased risk of cardiovascular disease, the effects could be even more serious. Therefore, people with stressful jobs who are at increased risk of cardiovascular disease should avoid high-fat meals, the researchers add.
These foods strengthen blood vessels
In other studies by the research group, it was also found that consuming healthier foods can completely prevent these impairments of vascular function. Foods with lots of polyphenols (e.g. berries, grapes and apples) are particularly suitable for this.
“Our studies show that food choices in stressful situations can worsen or protect against the effects of stress on our cardiovascular system,” emphasizes study author Dr. Catarina Rendeiro. In general, recovery from stress is less affected by consuming low-fat foods.
Avoiding fatty foods can help you deal with stress better, and it’s also a good idea to eat some berries before a stressful situation such as a job interview, says Baynham. (as)