Choose your comfort foods carefully. Stress eating may initially calm a worried mind, but according to a new study, certain fatty foods can also fuel more anxiety in the long run.
According to the study, consuming a particular type of high-fat diet (mainly saturated fats from animal products) altered the gut microbiome of lab rats and changed their behavior.
Rats on this diet also showed increased expression of genes involved in neurotransmitter activity, which specifically influence serotonin, a brain chemical known to increase anxiety.
Along with well-known risks like obesity or heart disease, these findings suggest that anyone who eats significant amounts of saturated fat should also consider the possible effects on mental health, says senior author Christopher Lowry, professor of integrative physiology at the University of Colorado Boulder.
“Everyone knows these are not healthy foods, but we tend to think of them strictly in terms of a little weight gain,” Lowry says. “If you understand that they also impact your brain in a way that can promote anxiety, the stakes are even higher.”
While most people experience times of intense worry and concern, some struggle with periods of more intense and relentless worry. anxiety that risk interfering with your daily life. It is estimated that 300 million people around the world live with a anxiety disorderaccording to the World Health Organizationmaking anxiety disorders the most prevalent of all mental disorders.
Anxiety is a complex and variable feeling shaped by many factors, and dietary influences remain poorly understood. Still previous research A similar link between high-fat diets and anxiety has also been shown in rats, and there is tracks of a similar association in humans.
In the new study, Lowry and her colleagues attempted to shed more light on this relationship between saturated fat and anxiety. They used adolescent male rats, divided them into two groups, and fed them different diets for nine weeks.
One group received a standard laboratory rat diet with about 11 percent fat. The other group received a diet with about 45 percent fat, mostly saturated fat from animal products.
The researchers used fecal samples to monitor the rats’ microbiomes throughout the study. After nine weeks, they also administered behavioral tests.
The rats on the high-fat diet not only gained weight, the researchers report, but also had a significantly lower diversity of gut bacteria than rats in the control group.
In addition to lower microbial diversity, rats on a high-fat diet had more bacteria from the phylum Firmicutes and less than Bacteroidetesa proportion that in humans is associated with obesity and a industrialized diet – i.e. lots of refined grains, processed meats and fried foods.
The researchers also observed elevated expression of three genes among the high-fat diet group. Those genes: tph2, htr1aand slc6a4 – are involved with the production and signaling of serotonina neurotransmitter that fulfills a series of important functions.
Although popularly pigeonholed as a mood enhancer, serotonin has many functions. helps us vomitfor example, and plays a key role in bodily processes such as wound healing and digestion.
The role of serotonin in depression remains cloudy, but it has a powerful influence on mood, and not always for the better. Some types of serotonin-producing neurons, the researchers explain, can trigger anxiety-like behaviors in animals when activated.
In the new study, the increased expression of those three genes among the high-fat diet rats was especially pronounced in the dorsal raphe nucleus cDRD, a brainstem region associated with stress and anxiety where most of the brain’s serotonin is produced, the study found.
In previous research in humans, increased expression of tph2 in cDRD has been linked to mood disorders, the researchers note.
“To think that just a high-fat diet could alter the expression of these genes in the brain is extraordinary,” Lowry said. says. “The high-fat group essentially had the molecular signature of a high-anxiety state in their brain.”
There are many types of fats, the study authors point out, and it would be foolish to lump them all together. Certain fats such as fish oil and olive oilFor example, they offer anti-inflammatory and brain-stimulating effects.
But saturated fats from animal sources are a different story. In addition to other potential health risks, Lowry’s research suggests that a diet high in these fats may promote anxiety in both the short and long term, especially at younger ages.
The study was published in Biological research.
