How obesity could affect the brain. Researchers have found extremely serious correlations

Bond between obesity and brain it is a fascinating subject that scientists have only recently begun to explore. New research adds important pieces to this puzzle.

From the size and functionality of the brain to certain neural circuits, recent studies, cited by medicalnewstoday they brought to light important aspects of the connection between obesity and the brain.

New studies on obesity and the links between it and the brain

For example, researchers published a study earlier this year that found a link between obesity around the stomach area and the smaller size of the brain – in particular, the lower volume of gray matter.

Findings from another recent study show that the prefrontal cortex of the brain – an area that is important for complex thinking, planning and self-control – is less active in people who tend to overeat, which can lead to obesity and growth. weight.

Finally, research that appeared only in May of this year has identified a number of neurons that can prevent overeating when they become active.

A new study now adds to this growing body of evidence, shedding further light on the connection between obesity, on the one hand, and differences in brain structure and shape, on the other.

Big belly, little brain

Dr. Ilona A. Dekkers of Leiden University Medical Center in the Netherlands decided to investigate how obesity could affect the brain .

So scientists examined brain scans from more than 12,000 people who took part in the Biobank imaging study in the United Kingdom. The brain imaging techniques used by the team in the study provided information about the participants’ gray and white matter.

Describing the brain in very broad terms, this central processing unit consists of an “outer cortex of gray matter and an inner area that houses tracts of white matter.”

The gray matter is full of neurons, while the white matter consists mainly of nerve projections called axons and glial cells.

In the current study, according to Dr. Dekkers, the team found that “having higher levels of fat distributed throughout the body is associated with lower volumes of important brain structures, including gray matter structures that are located in the center of the brain.”

“Interestingly, I noticed that these associations are different for men and women, which suggests that gender is an important modifier of the link between fat percentage and the size of specific brain structures,” she adds.

Specifically, obese men had a lower volume of gray matter both in general and in certain reward processing circuits and movement brain structures.

For obese women, an increased amount of body fat is correlated only with a lower volume of matter in a region called globus pallidus, which is an area of ​​the brain that plays a role in voluntary movement.

In both men and women, there was a correlation between a higher amount of body fat and the chance of small changes in the white matter of the brain.

5 ways in which obesity affects the brain

Studies show that these changes in the brain due to obesity can in turn fuel overeating, leading to a vicious circle that makes it difficult to lose and maintain weight, according to livescience.

Here are five ways in which obesity changes the brain:

1. Obesity causes food “addiction”

Fattening can desensitize the brain to the pleasure we get from sugary and fatty foods, causing us to eat more cakes and pastries than we did when we were weaker, research shows. A similar effect is seen in drug users, who eventually need more cocaine or heroin to reach their initial level.

In a September 29 study in the Journal of Neuroscience, researchers scanned women’s brains while drinking a milkshake. They saw that the sugar drink activated an area known as striatum. Half a year later, the researchers repeated the experiment on the same women, some of whom gained weight. The more women gained weight in the meantime, the less their brains responded to milkshakes in the second experiment.

Animal research has also shown that rats fed a high-sugar, high-fat diet are less sensitive to the pleasure-inducing neurotransmitter dopamine.

2. Obesity can make us more impulsive

In obese children, a region of the brain responsible for impulsive control, called the orbitofrontal cortex, appears to be smaller than that of weak children, according to a study presented this year at the meeting of the American Academy of Child and Adolescent Psychiatry in New York. York. Moreover, the smaller this region of the brain, the more likely it was that adolescents would eat impulsively, the researchers said.

Although the study did not show a cause-and-effect relationship, childhood obesity may reduce the size of their orbitofrontal cortex, the researchers said. Obesity is known to cause changes in the immune system, stimulating inflammation in the body. This increased inflammation can have an impact on the brain and “leads to a vicious circle, in which obesity leads to inflammation, which damages certain parts of the brain, which in turn leads to a more uninhibited diet and more obesity.” , said the study’s researcher, Dr. Antonio Convit, of New York University School of Medicine.

3. Obesity increases the risk of dementia

Having more belly fat is associated with a decrease in the total brain volume in middle-aged adults, according to a study published in May in the Annals of Neurology. It is possible that the extra fat will trigger the inflammation, which puts stress on the body and can have an impact on the brain, the researchers said.

The discovery suggests something special about abdominal fat, also known as visceral fat, the fat between the organs in the abdominal cavity may play a role in reducing the size of the brain. Visceral fat releases a unique profile of HORMONEwhich may have an impact on the body in a different way than hormones released by subcutaneous fat or fat under the skin, the researchers said.

Previous studies have found that people with lower brain volumes have a higher risk of dementia and tend to perform poorer on cognitive tests.

4. The yo-yo diet can cause excessive food consumption under stress

Studies suggest that it’s not just weight gain that changes the brain. Diet can change the way the brain responds to stress, so the next time we are in trouble or simply lose weight, we eat more, according to a study published Dec. 1 in the Journal of Neuroscience.

In the study, researchers put a group of mice on a diet so that they could lose between 10 and 15% of their body weight. Then mice were allowed to lose weight, similar to how dieters often see their weight back. When mice were exposed to stressful situations, such as hearing sounds at night, they ate more food than those who had never been on a diet.

Mice also had what are known as epigenetic changes in the way genes are expressed, which does not involve changes in the gene sequences themselves, especially in the genes involved in regulating stress responses. The researchers said that these changes could have changed the feeding behavior of the animals during stress.

5. Obesity severely damages memory

Obesity can affect memory, at least for postmenopausal women. A July 14 study published in the Journal of the American Geriatric Society looked at memory test scores for 8,745 women between the ages of 65 and 79. The researchers found that a 1-point increase in a woman’s body mass index (BMI) was associated with a 1-point increase. decrease to a 100-point memory test.

Fat-releasing hormones could affect memory, the researchers said. These hormones can cause inflammation, which can affect cognition.

In short, a person’s weight has a direct impact on how their brain works. Obesity can also be caused by certain it hurts or medications and may be exacerbated by factors such as genetics, stress or lack of sleep, he writes healthcentral.com.

But it is good to know that obesity influences the executive function of the brain, that is, the part that helps us perform our daily tasks. And studies have also found a link between obesity in middle age and the risk of developing Parkinson’s disease.

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