- Obesity is directly related to the development of more than 100 diseases, such as diabetes, sleep apnea, osteoarthritis, hypertension, cardiovascular diseases and multiple types of cancer.
- It is estimated that at least 1.9 billion adults and 340 million children and adolescents suffer from this disease.
- Unicef lists Mexico as the country with the highest rate of childhood obesity in the world.
During the last decades, obesity has become a serious global public health problem. According to the World Health Organization (WHO), it has already reached epidemic proportions of concern. It is estimated that since 1975 this disease has tripled. Thus, in 2016 there were 1.9 billion adults and 340 million children and adolescents affected. But although this is not a justification, it is now known that the food addiction is real and has to do with some molecules.
Before proceeding, it is necessary to remember that the Obesity is a multifactorial disease characterized by the abnormal accumulation of fat that generates a state of chronic inflammation in the body. In addition, it is the first step for other serious pathologies such as high blood pressure, type II diabetes, high levels of cholesterol and triglycerides, osteoarticular problems, risk of cancer, sleep apnea and cardiovascular problems.
Now, in a delicate brain balance between the functions of the limbic system, where impulses occur, and the cerebral cortex, which controls rational activity, lies the vulnerability to addictions.
In the case of food addiction, a group of epigenetic markers (those capable of modifying genes) called microRNAs work in this area. They are small RNA molecules that regulate gene expression in a complex way.
A team of Spanish scientists, led by Rafael Maldonado López, from Pompeu Fabra University in Barcelona, Spain, identified these markers. First in a mouse model and then in humans, which participate in compulsiveness, motivation and resistance to punishment, behaviors associated with food addiction.
Maldonado gave a remote conference at the Seminar on Neurosciences and Addictions of the Cannabinoids Laboratory of the UNAM School of Medicine. His presentation was in charge of the professor of that academic entity, Óscar Prospero García.
“The criteria for addiction to food is defined based on the criteria for drug addiction, in that behavioral alteration. It consists of persistence to respond, the insistence on the search for food, with enormous motivation and consumption despite its negative consequences.
He explained that in the study they compared two populations of mice. One addicted to food and one not, and they found microRNAs with higher expression in the addicted rodents. By replicating the study in humans, they identified that the same microRNAs affected in those animals were also altered in people.
“The similarities between the results in mice and humans add great importance to the study. The role of epigenetics in vulnerability to food addiction opens the door to being able to identify biomarkers for early diagnosis, and to be able to develop future therapies by modifying the expression of microRNAs”.
The three identified markers are: miR 29C, miR 137 and miR 665, and it was shown that the expression of these molecules is associated in both groups (mice and humans) with food addiction.
In the first part of the investigation, the Spanish scientists detected the Neurobiological mechanisms that allow the development of food addiction behavior. Specifically, certain cortical areas in the brain that participate in the loss of control of eating.
The experts wondered why some individuals are resilient while others are addicted. The answer was found in epigenetic factors, that is, those external to the environment that modify the expression of genes.
In a study currently underway, Maldonado and his collaborators study the gut microbiota. Specifically, the function of some bacteria present in our body that are related to food addiction. So far, they have found that there is a relationship between the gut and the brain, and that the microbiota could contribute to some specific brain functions.