Food preferences recorded in the brain analyzed to reduce obesity

Eating high-calorie foods produces pleasurable sensations. We innately like some foods from birth; there are also acquired tastes.

Food preferences recorded in the brain analyzed to reduce obesity
Researchers analyze food preferences registered in the brain trying to reduce obesity. Photo by Pablo Merchán Montes / Unsplash

Current drugs for the treatment of obesity are not very effective, or they cause considerable side effects since some are amphetamines that can produce addiction and perhaps a more serious problem; the only intervention with a high success rate is bariatric surgery, but it is an invasive process with limited availability, said the doctor in Biomedical Sciences, Jean-Pascal Morin.

The researcher from the UNAM School of Medicine said that in terms of reeducation or therapeutic efforts, some also produce changes at the brain level, although more remains to be discovered. "We are in diapers in the generation of drugs". The specialist heads the research line the "Role of cholinergic neuromodulation in the amygdaline nuclei during gustatory learning" and he expressed:

A better understanding of the brain processes by which experience modifies our eating habits is likely to contribute to treating behavioral pathologies, such as obesity, related to excessive food intake. Our threshold for detecting sweet tastes is high, and the consumption of high-calorie foods produces pleasurable sensations.

This process is part of taste memory and allows us to feel pleasure when consuming certain foods, a function performed by the cerebral amygdala, the main control nucleus for emotions and feelings, in addition to our responses of satisfaction or fear, which is located in the basal anterior part of the brain.

The FM professor emphasized that as part of the basic research he is conducting together with other experts from Mexico and Israel, they found that in particular, the amygdala participates in the phenomenon known as food neophobia; that is, the fear of rejection of trying new or unknown foods, a primitive protective reflex, especially in children.

It is a small structure located in the limbic region of both hemispheres of the brain involved in learning, memory, and emotion processing. Results obtained in laboratory animals have determined that this area of the brain - especially because of the role played there by a neurotransmitter called acetylcholine - determines how the experience of different flavors modifies our food preferences.

Jean-Pascal Morin highlighted the existence of studies showing how food neophobia is increased in animal models by obesity. "In human patients, that fact could be explained by the lack of diversity in their diet." That is, the excessive intake of carbohydrates and fats, and the dietary lack of fruits and vegetables, for example.

People, from the moment we are born, innately like some foods, such as a cake or something sweet; however, there are other flavors for which we can develop a strong pleasure, although we are not necessarily born with this preference, this is called acquired flavors or tastes, such as coffee, wine or some strong cheeses, for example.

A structure of the basal forebrain, the amygdala, receives information related to the taste stimulus coming from different parts of the brain, and with the data, it generates a kind of representation or learning of the parts of the brain to physically modify its structure. Then there are connections or synapses between neurons of the amygdala and other structures, which can be strengthened or weakened, according to our experience.

"This is how memories, preferences and even the relationship between obesogenic foods and drugs of abuse are forged, and that is the direction our research is heading, although at a basic level," he argued.

The expert in taste memory clarified: although they do not carry out studies aimed directly at intervening in these disorders, they analyze how food preferences are acquired, a fundamental aspect of the ingestion behavior on which not only we, but also several research groups around the world, are working.

A better understanding of the brain processes involved in the formation of taste preferences, which often have a strong emotional component, will undoubtedly help to develop better treatments against overweight and obesity, endemic in Mexico.

It is not possible to manipulate the amygdala in a physical or invasive way to treat obesity since it is a deep area of the brain, nor is this disorder exclusive to brain plasticity or food addiction, there are multiple factors involved, some inherited (genetic), others metabolic, but above all psychosocial.

Perhaps the course of this research could lead to the development of drugs that could prevent, when administered before the consumption of certain obesogenic foods, the amygdala from continuing with the development of preferences towards these products, even forming a slight aversion.