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New research suggests that eating fatty comfort foods can make the effects of stress worse, increasing your risk of cardiovascular disease. Grace Cary/Getty Images
  • Studies show that people tend to eat fatty comfort foods when they are stressed.
  • However, a new study has found that these foods may make the effects of stress worse.
  • People who ate fatty meals had greater signs of endothelial dysfunction.
  • Endothelial dysfunction can increase the risk of problems like cardiovascular disease.
  • Experts say plant foods have compounds that may help reduce endothelial dysfunction.

Do you tend to reach for fatty comfort foods like ice cream and potato chips when you are under stress? If so, you may want to think twice, according to researchers at the University of Birmingham in Birmingham, United Kingdom.

A new study, which was published in the journal Frontiers in Nutrition, found that eating high-fat foods prior to stressful events could have detrimental effects on endothelial function.

The endothelium is a single layer of cells lining the blood vessels. When it is functioning properly, it is involved in the constriction and relaxation of blood vessels. It also manages the movement of fluids and other molecules to the tissues of your body.

Endothelial dysfunction can lead to an increased risk of cardiovascular disease, clogged arteries, and high blood pressure.

According to the study authors, stress is known to cause a decline in endothelial function for around 15 to 90 minutes after a stressful event in healthy, young adults.

Additionally, studies report that people tend to overeat fatty and sugary foods when they are under stress, which can have adverse effects on the blood vessels, including endothelial dysfunction.

Given these facts, the authors thought that there might be some interplay between the effects of stress and fat consumption that would cause blood flow to be even further impaired.

To study whether this was indeed the case, the researchers recruited 21 healthy volunteers, split nearly evenly between male and female participants.

They were each given a breakfast composed of two butter croissants and then asked to do an eight-minute mental stress test. For the test, they were required to solve math problems in their heads with gradually increasing speed. They also received an alert when they got an answer wrong.

The purpose of the test was to simulate the stress that a person might feel on an average day.

The function of the participants’ vascular systems was tested by using a method called “flow-mediated dilatation” to measure blood flow through an artery in the arm.

The team of scientists found that eating fatty foods when feeling stressed led to a reduction in vascular function of 1.74%. This was in contrast with the 1.18% reduction that was seen when people ate a low-fat meal while undergoing testing.

The authors noted that previous studies have shown that even a 1% reduction in function can cause a 13% rise in cardiovascular disease risk.

They further stated that the decline in vascular function lasted as long as 90 minutes after the math test had ended in people who ate the high-fat meal.

In a press release, the researchers also note that they found eating high-fat foods had negative effects on oxygenation in the pre-frontal cortex, the area of the brain responsible for higher-level cognitive processes.

People who had eaten the high-fat meal experienced a 39% reduction in oxygenated hemoglobin (the component of red blood cells that carries oxygen) when compared to those who had eaten a low-fat meal.

According to Kelsey Costa, MS, RDN, a registered dietitian and nutrition consultant for the National Coalition on Healthcare, “The study indicates that consuming high-fat foods during times of stress may delay the body’s healing process, specifically the functioning of the endothelium (inner lining of blood vessels), which suggests that stress eating these types of foods might have a detrimental effect on the vascular health of young, otherwise healthy individuals.”

Costa added, however, that it’s not clear how fat consumption hinders post-stress recovery.

She said it could be, as the researchers suggest, that increased triglycerides and C-reactive protein following fat consumption could be to blame.

“This may lead to direct injury to the vascular wall or indirectly cause endothelial dysfunction by elevating oxidative stress,” said Costa.

She further noted that increased triglycerides and C-reactive protein could stimulate vasoconstrictor and inflammatory markers, reducing endothelium-derived nitric oxide, which could then impair endothelial function.

“Future research should aim to scrutinize these mechanisms further and assess the impact of fat on vascular responses during stress,” she remarked.

Robert Iafelice, MS, RD, LDN, who is a Medical Reviewer at SET FOR SET, said it’s stress that drives our desire for fatty foods in the first place.

“People experiencing psychosocial stress tend to eat an unhealthy diet,” he said. “Stress triggers the release of high amounts of cortisol, often called the ‘stress hormone.’ High cortisol is linked to an increased appetite for calorie-dense foods, e.g., fatty foods, refined grains, and processed foods with added sugar.”

However, while eating these high-energy foods might have been helpful for our ancestors after fighting a predator or running away from danger, this stress reaction does not serve us well when it comes to mental or emotional stress.

Iafelice noted that both high cortisol and unhealthy foods can lead to an increase in abdominal obesity, which is one component of metabolic syndrome.

Metabolic syndrome is a group of conditions linked with increased risk for both cardiovascular disease and diabetes, explained Iafelice.

Knowing that foods high in fat aren’t doing us any favors, it’s important to make better choices when it comes to protecting our vascular health.

Costa said it is generally accepted that plant-based foods rich in bioactive compounds — such as fruits, vegetables, whole grains, and legumes — can have positive effects on endothelial function.

“These foods are abundant in antioxidants and polyphenols, which have anti-inflammatory and vasodilatory effects,” she explained.

She also pointed to studies showing that certain foods, in particular, can help improve endothelial dysfunction, such as blueberries, beetroot, and plums. Polyphenol-rich drinks like green tea and pomegranate juice might also help, she said.

“Healthy fats, such as omega-3 fatty acids found in cold-water fish, algae oil, nuts, and seeds, may also have a protective effect on the vascular system,” added Costa.

“Additionally, including probiotics through fermented foods or supplements can enhance gut microbiome diversity, which has been linked to improved endothelial function,” she concluded.

According to a new study, eating fatty comfort foods when you are stressed may add to the deleterious effects of stress on endothelial function.

People who had a fatty meal prior to a stressful event had reduced blood flow in their arms and lower levels of oxygen in the prefrontal cortex of their brains, presumably due to impaired endothelial function.

However, nutritionists say that plant foods — such as fruits, vegetables, whole grains, and legumes — contain compounds that can reduce endothelial dysfunction.

Omega-3 fatty acids and probiotics might also help protect vascular health.