Obesity is a very dangerous handicap, a fact we all know about. But the more researchers study the subject, the more they realize that the scope of its negative effects is large and disturbing. Now, and after a first study by other researchers on the subject, new evidence suggests that the so-called central obesity (characterized in particular by a waist circumference of the stomach significantly greater than that of the hips) is associated with a narrowing of the brain. In addition, this same brain atrophy was identified as a risk factor for the development of neurodegenerative diseases.
New research suggests that the brains of obese people are also greatly affected by the problem, although the causes and effects are still not well understood by scientists. However, one of the known elements is the link between a "shrunken" brain and obesity. This link had already been identified in an earlier study published in January 2019 by another independent research team.
In this new research, an MRI of more than 12,000 adults who participated in the British Biobank study on high body fat levels shows changes in brain shape and structure, as well as a reduced amount of gray matter.
That is, the gray matter contains most of the nerve cells in the brain and also includes brain regions involved in self-control, muscle control and sensory perception. " We found that having higher levels of distributed fat in the body was associated with smaller volumes of important brain structures, including gray matter structures located in the center of the brain. Said Ilona A. Dekkers, a radiologist at the Medical Center of the University of Leiden in the Netherlands.
In this new study, which looked at people between the ages of 45 and 76 (with a mean age of 62), the researchers found that the nature of associations was different for men and women:
- In men: a higher percentage of total body fat was related to the reduction of total gray matter (including the thalamus and hippocampus, but excluding the amygdala).
- In women: an increase in body fat was associated with a reduction in gray matter in only one part of the brain: globus pallidus, an area associated with voluntary movement.
However, gray matter was not the only one to be affected by obesity. In fact, the results also showed that the white matter, which is a class of central nervous system tissue containing bundles of nerve fibers that connect various regions of the brain, was also affected by fat levels. body, exhibiting microscopic changes in its structure – although the effects of these changes are unclear.
Researchers acknowledge that, because of the limited data available at the time, their study looked at no connection to the actual participant's cognitive decline, but only to the structure of the brain. As a result, they point out that we still do not know how the causality of these effects works. It is for this reason that we can only speculate on the aspects of the narrowing of the gray matter and what they could mean in terms of behavior.
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" Other factors besides the influence of obesity on the brain structure may also be possible through neuronal influence on body weight regulation and eating behavior. Write the researchers in your article. " Obesity suggesting regulation of eating behavior may be influenced by a change in inhibitor control, decreasing gray matter volume and affecting signaling pathways of the cortico-limbic tract. ", Add the researchers.
Scientists suggest that it is possible for excess fat to affect the central nervous system through the cardiovascular system. Of course we must now avoid any hasty conclusion about how these relationships work. Studies such as these do not rule out the possibility that loss of gray matter also makes it difficult to lose weight. This will require more studies to understand more about these close links.
As a result, there is still much research to be done so that we can learn more to better understand the causes and effects involved. " Further research is needed to assess whether strict weight reduction and the treatment of related metabolic disorders are also beneficial for the possible neurological consequences of obesity. ", Add the authors of the study.
However, these results confirm once again that the link between obesity and neurology needs to be carefully examined. The research team therefore now wants to focus on determining the different types of associations linked between gray matter shrinkage and obesity.
Note that recently, many discoveries have also highlighted the relationship between the physiology of our intestines and the functioning of our brain. It is not so surprising that body fat can have a significant impact on brain volume.