University of Montreal researchers say that fatty foods can change our brain chemistry, and withdrawing from such foods can trigger depression. Researcher Stephanie Fulton says that even before obesity occurs, eating fatty and sugary foods causes chemical changes in the brain, meaning that going on a diet might feel similar to going through drug withdrawal.
"By working with mice, whose brains are in many ways comparable to our own, we discovered that the neurochemistry of the animals that had been fed a high fat, sugary diet were different from those who had been fed a healthy diet," Fulton explained. "The chemicals changed by the diet are associated with depression. A change of diet then causes withdrawal symptoms and a greater sensitivity to stressful situations, launching a vicious cycle of poor eating."
Over a six week period, Fulton and her team fed one group of mice a low-fat diet and a second group a high fat diet, monitoring how the different foods affected the way the animals behaved. Specifically, they used a variety of techniques to evaluate the relationship between rewarding mice with food and their resulting behavior and emotions. The researchers also examined the brains of the mice to see how they had changed.
Fulton found that mice fed the higher-fat diet exhibited signs of being anxious, such as an avoidance of open areas. Moreover, their brains were physically altered by their experiences - in particular, dopamine levels.
Dopamine - found in mice and humans - is involved with our brain's reward circuitry. Dopamine is linked to a molecule called CREB, which controls the activation of genes involved in the production of dopamine and also contribute to memory formation.
"CREB is much more activated in the brains of higher-fat diet mice and these mice also have higher levels of corticosterone, a hormone that is associated with stress. This explains both the depression and the negative behavior cycle," Fulton said. "It's interesting that these changes occur before obesity. These findings challenge our understanding of the relationship between diet, the body and the mind. It is food for thought about how we might support people psychologically as they strive to adopt healthy eating habits, regardless of their current corpulence."
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Source: University of Montreal