What causes food addiction?

Scientists have discovered the area of the brain that triggers food addiction.

The urge to eat is a primal one, but compulsive behaviours to eat to excess can lead to obesity and eating disorders. 

A team of researchers have identified a special circuit in the brain that can trigger and alter addictive behaviours towards food. 

Researchers from Pompeu Fabra University (UPF), in collaboration with University of Mainz, Germany, the Centre for Genomic Regulation, Instituto Cajal, Johannes Gutenberg University, Germany, the Autonomous University Barcelona and Hospital del Mar carried out a study that used mice as a model animal to investigate the relationship between the brain and compulsion to eat. The scientists used the mice to mimic the behavioural abnormalities associated with food addiction in humans.

The findings published in the journal Nature Communications found that the circuit that goes from the prefrontal cortex to the nucleus accumbens, an area of ​​the limbic system related to the reward and pleasure processes is responsible for “loss of control” when eating. Research also demonstrated that an overexpression of the dopamine D2 receptor in the outer surface (cortical level) of the brain is directly linked to compulsion to eat excessively and a loss of ability to control behaviour. The dopamine D2 receptor has previously been associated with drug addiction.

Compulsive eating or “loss of control” while consuming food is difficult to manage and there are currently no effective treatments to ease symptoms. Food addiction has been said to have similar neurobiological mechanisms commonly found with drug addiction. Both brain disorders are chronic and complex, resulting from the interaction of multiple genes and environmental factors affecting a person’s choices and behaviours. 

Rafael Maldonado, director of the Laboratory of Neuropharmacology at UPF and one of the leaders of the study commented: "The identification of a specific cortical area correlating to the loss of control when eating may be significant for the prevention and treatment of food addiction disorder. Cortical areas are the brain structures of maximum hierarchical order for the control of behaviour and therefore represent brain areas of enormous therapeutic interest." 

The authors have shown that an activation of the circuit from the prefrontal cortex to the nucleus accumbens gives better control when dealing with food, while a decrease in the activity of the circuit causes the loss of inhibitory control - meaning an increased likelihood of addictive behaviour.

Maldonado adds: “There is currently some controversy about how to classify this important behavioural disorder; and our findings strengthen the idea that eating addiction exists and shares common features with drug addiction

“We suggest that a possible therapeutic target for food addiction disorder could be the stimulation of the specific brain circuit identified, of which fairly precise stimulation techniques already exist.”

In a world where obesity is a growing health concern and eating disorders are ever more prevalent, these innovative findings could be key to the development of new treatment methods to help control overeating and food addiction.