An American team of researchers has identified 26 genetic regions in the brains of patients whose mutation is likely to trigger a preference for fatty, salty and sweet foods, which could explain why some people suffer from obesity.
- Conducted on more than 280,000 participants, the study highlights the existence in the brain of 26 genetic regions containing specific neuron subtypes.
- When these neurons are activated, they react to proteins, fats or carbohydrates.
- This genetic variation in neural signals may trigger an increased craving for fatty, sweet and salty foods and therefore may explain why some people make unhealthy food choices.
In 2020, according to the World Health Organization (WHO), overweight and obesity affect more than 2 billion people worldwide. In France, it is estimated that obesity affects nearly 7 million people, or about 15% of the population. This condition does not spare the youngest. 18% of adolescents are thus overweight and 5% suffer from severe obesity.
Not only harmful to their health, overweight and obesity are also, for those concerned, a source of psychological suffering. Often blamed for their food choices, obese people suffer from society’s view of their condition. It is often thought that they eat too many fatty, salty and sugary foods.
Yet obese people are not fully responsible for these unbalanced food choices. This is shown by a new study conducted by a team of researchers from Massachusetts General Hospital (MGH), Boston University School of Public Health (BUSPH). In a study published in the journal Nature Human Behaviorthey explain that they have identified more than twenty genetic regions likely to affect the food intake of individuals.
26 Genetic Regions Involved in Preference for Unhealthy Foods
In their article, the authors explain how the brain is influenced by various signals which themselves impact the eating behavior of individuals and regulate the energy balance of their body. But genetic variation in these signals can lead to extreme hunger and therefore obesity.
According to co-lead author Jordi Merino, studies have already begun to “identify brain regions and molecular processes that influence food intake, but little research has been conducted in humans to identify the molecular signatures that underlie variable susceptibility to food choice behavior”.
To identify them, the researchers therefore carried out a genetic analysis and examined the food consumption of 282,271 participants of European ancestry from the UK Biobank and the CHARGE consortium (Cohorts for Heart and Aging Research in Genomic Epidemiology).
A total of 26 genetic regions were identified as being associated with an increased preference for foods containing more fat, protein or carbohydrates, and these regions were enriched in genes expressed in the brain.
Moreover, the computational analyzes carried out highlighted specific subtypes of specialized neurons distributed throughout the central nervous system. When activated, they respond to protein, fat, or carbs, which may explain why people are more likely to prefer foods or meals with higher amounts of fat, protein, or carbs.
The discovery of these genetic variants may be used in future analyzes to determine whether diet composition is causally linked to metabolic diseases such as type 2 diabetes and obesity. “These results will also provide a better understanding, from a biological point of view, of why eating behavior differs between individuals and could provide new avenues for the prevention and treatment of obesity and other diseases. metabolic diseases,” the study authors note.
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