Neurobiology of the metabolic syndrome: an allostatic perspective

The metabolic syndrome is a cluster of more or less related metabolic and cardiovascular derangements including visceral obesity, insulin resistance, blood and tissue dislipidemia, high blood pressure and it is often associated with neuroendocrine and immunological dysregulations. The aetiology of this syndrome is clinically highly relevant because it predisposes to life-threatening complications, such as Diabetes Mellitus, kidney failure, cardiovascular disease, and certain types of cancer. Contributing factors include a sedentary life-style combined with increased dietary fat intake and psychosocial stress. From a biological viewpoint, however, the metabolic syndrome can be considered as a maladaptive consequence of an initially successful adaptation to high environmental demands. As opposed to pre-historic times - when environmental demands were usually energy-costly (e.g., fight/flight/hunt) and nutritional resource often inadequate - energy-utilizing actions serve no longer an optimal solution to deal with environmental demands of current human society. This paper describes the interactions between psychosocial stress and nutrition and how these may affect emotional and metabolic components of the metabolic syndrome. A deeper understanding of these interactions is necessary to come to effective treatment and prevention of the metabolic syndrome in the future.