Eating greasy foods during stress can affect blood flow
The study authors stated that stress is known to cause a decrease in endothelial function in healthy young adults approximately 15 to 90 minutes after experiencing a stressful event.
Additionally, studies report that people under stress tend to eat excessive amounts of fatty and sugary foods, which can have adverse effects on blood vessels, including endothelial dysfunction.
Given these facts, the authors believe there may be some interaction between the effects of stress and fat consumption, leading to further impairment of blood flow.
To investigate whether this was indeed the case, the researchers recruited 21 healthy volunteers, with an almost even split of male and female participants.
They each ate a breakfast of two buttery croissants and then were asked to take an eight-minute mental stress test. During the test, they were asked to solve math problems in their heads at a progressively faster pace. They also receive alerts when they answer incorrectly.
The purpose of the test is to simulate the stress a person might feel on a daily basis.
Participants' vascular system function was tested by measuring blood flow through the arm's arteries using a method called "flow-mediated dilation."
A team of scientists found that eating greasy food when feeling stressed can lead to a 1.74% decrease in blood vessel function. This contrasts with the 1.18% decrease observed when people were tested eating low-fat meals.
The authors note that previous research has shown that even a 1% reduction in function is associated with a 13% increase in cardiovascular disease risk.
They further noted that the decline in blood vessel function lasted up to 90 minutes after the math test in people who ate a high-fat meal.
In a press release, the researchers also noted that they found that eating high-fat foods negatively affects oxygenation in the prefrontal cortex, the area of the brain responsible for higher-order cognitive processes.
Those who ate the high-fat meal had 39% less oxygenated hemoglobin (the component of red blood cells that carries oxygen) than those who ate the low-fat meal.
Why fat magnifies the effects of stress
Research shows that eating high-fat foods during times of stress may delay the body's healing process, specifically the function of endothelial cells. lining of blood vessels, suggesting that the stress of eating such foods may adversely affect vascular health in young, healthy individuals.
However, it is unclear how fat consumption impedes recovery after stress.
As the researchers suggest, this may be the reason why triglycerides and C-reactive protein increase after fat ingestion.
This may lead to direct damage to the vessel wall or indirectly to endothelial dysfunction through increased oxidative stress.
Increases in triglycerides and C-reactive protein can stimulate vasoconstrictor and inflammatory markers and reduce endothelium-derived nitric oxide, thus impairing endothelial function.
Future studies should aim to further examine these mechanisms and evaluate the impact of fat on vascular responses during stress.
Why people tend to eat greasy foods when under stress
The first is that stress drives our cravings for fatty foods.
People experiencing psychosocial stress tend to eat unhealthy foods. Stress triggers the release of large amounts of cortisol, often called the "stress hormone." High cortisol is associated with an increased appetite for high-calorie foods, such as fatty foods, refined grains, and processed foods with added sugar.
However, while eating these energy-dense foods may have helped our ancestors after fighting a predator or escaping danger, this stress response doesn't serve us well when it comes to mental or emotional stress.
High cortisol and unhealthy foods can both contribute to increased abdominal obesity, a component of metabolic syndrome.
Metabolic syndrome is a group of conditions associated with an increased risk of cardiovascular disease and diabetes.
Foods that Reduce Endothelial Dysfunction
Knowing that high-fat foods do us no good, it's important to make better choices when it comes to protecting the health of our blood vessels.
It is widely believed that plant foods rich in bioactive compounds—such as fruits, vegetables, whole grains, and legumes—can have a positive impact on endothelial function.
These foods are rich in antioxidants and polyphenols, which have anti-inflammatory and vasodilatory effects.
Research shows that certain foods in particular can help improve endothelial dysfunction, such as blueberries, beetroots and plums. Polyphenol-rich beverages like green tea and pomegranate juice may also be helpful.
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.
Additionally, adding probiotics via fermented foods or supplements can enhance the diversity of the gut microbiome, which is associated with improved endothelial function.
Eating fat-rich comfort foods when you're stressed may increase the harmful effects of stress on endothelial function, according to a new study.
People who ate fatty foods before a stressful event had reduced blood flow to their arms and lower oxygen levels in the brain's prefrontal cortex, possibly due to impaired endothelial function.
However, nutritionists say plant-based foods—such as fruits, vegetables, whole grains, and legumes—contain compounds that may reduce endothelial dysfunction.
Omega-3 fatty acids and probiotics may also help protect blood vessel health.