An excessive consumption of fats in a diet can cause brain changes that lead easily to a kind of anxious and depressive symptoms, and it was found that even though there may be a reversal of metabolic values with a change of diet, mood disorders persist.
This result is achieved after a study on rats, which showed that a diet high in fat is linked to type 2 diabetes, anxiety and depression and that this diet blunts the beneficial effect of antidepressants.
The research was led by researchers at the University of Toulouse and Dijon in France.
The researchers said that in the literature there is a debate to determine whether there is a link between the type-2 diabetes and major depression.
This study provides evidence present some of this bond, with an original approach based on the z-score method, especially when the type 2 diabetes is caused by a prolonged diet with a high fat content.
For the study, the researchers fed 30 mice with a standard diet, a diet rich in fat, or enriched with fructose for 60%, for a maximum of 16 weeks. Body weight was monitored weekly.
The animals were subjected to a complete analysis of metabolic and behavioral.
To the mice receiving the standard diets and high-fat were administered subcutaneously antidepressants and anxiolytics for 4 weeks at a dose active.
As expected, the high-fat diet was associated with an increase in body weight, which was accompanied by fasting hyperglycemia, hyperinsulinemia, and glucose intolerance. The diet high in fructose has been associated with the development of the characteristics of type-2 diabetes even if the body weight is not increased.
The researchers found that there was a correlation between the development of metabolic symptoms and a diet high in fat and anxious-depressive symptoms, which have increased over time.
The high-fat diet was also associated with decreased levels of extracellular serotonin in the hippocampus, which researchers suggest may result from increased sensitivity to 5-HT1A receptors.
The team also found that, even if the reinstatement of a standard diet for 1 month after 12 weeks of high fat diet reversed weight gain and metabolic changes, there have been persistent symptoms of depression and anxiety-producing.
Other studies will be needed before the results can be translated to humans to show a direct link between diet and anxiety and depression, but the premises are very encouraging, especially on the molecular mechanisms underlying this relationship and on factors such as the role of polymorphisms and antidepressant therapies preventive.