The health consequences of obesity are numerous: diabetes, high blood pressure, cancer risk, etc. But there is also a tendency of obese people to be depressed. A surprising phenomenon, the mechanism of which the University of Glasgow researchers have finally explained.
“When we feel depressed, we tend to eat. The consumption of fatty foods gives us comfort. But in the long run, it can have the opposite effect,” says George Baillie, a researcher at the University of Glasgow, Scotland. He and his team have just discovered the process that links obesity and depression.
Researchers at the University of Glasgow have been working on a mice model and discovered that saturated fatty acids tend to enter the brain via the bloodstream. They then accumulate in areas that control mood. In fact, mice that fed on a high-fat diet showed a high influx of dietary fatty acids into the hypothalamus region.
In the course of the new treatments
The researchers also observed an increase in the concentration of the free fatty acid receptor 1 (FFAR1) and a disruption in the signaling pathway of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA), a protein suspected of playing an important role in the development of depression. On the other hand, a deficiency of an enzyme called phosphodiesterase 4A (PDE4A) – an enzyme involved in the breakdown of cAMP – has played a protective role in mice.
Clearly, a high-fat diet may very well interfere with the function of the hypothalamus by activating the enzyme PDE4A and thus suppressing the cAMP/PKA signaling pathway. This discovery offers hope for the development of new therapies. It has been shown that conventional antidepressants take longer to work in overweight people. In addition to being less effective in obese people, it also takes antidepressants longer to work in them.