Cracking Under Stress

Connecting the Dots: Stress, Inflammation, and Obesity

Research is helping to connect the dots between various kinds of stress, inflammation, and obesity. Psychological stress has long been linked to obesity through activation of the sympathetic nervous system and by seeking comfort from fatty, salty, and sugary foods associated with weight gain. Obesity itself seems to cause physiological stress responses. Those responses in turn activate inflammation and the metabolic diseases of obesity — diabetes, heart disease, liver disease, and a host of others.

Three new publications in the last few weeks have brought insight into diverse aspects of the connections between stress, inflammation, and obesity.

Chengcheng Jin and Richard Flavell published a review of new research that explains the immune pathways linking stress and inflammation to obesity. Stress receptors called pattern recognition receptors (PRRs) are key. Excess nutrients in obesity activate these PRRs as if they were a signal of a pathogen or other stressor. They trigger an inflammatory response that causes chronic low-grade inflammation in the brain, pancreas, liver, muscle, and fat tissue. The inflammation leads to insulin resistance, energy imbalance, more obesity, and the metabolic disorders of obesity.

A recent study published in Obesity found that prolonged financial stress predicts subsequent obesity. Mohammad Siahpush and colleagues concluded that financial stress is an important predictor for the development of obesity, independent from more common social and economic measures such as income and education.

Finally, another study recently published in Obesity demonstrates that successful surgical treatment of obesity reduces the expression of genes linked to the inflammatory pathology of asthma. Said lead author Paresh Dandona:

Ours is the first study to provide a mechanistic link between obesity and asthma through biological and immunological mechanisms. There has been, until now, no biological, mechanistic explanation other than the fact that obesity may raise the diaphragm and thus reduce lung volumes.

Clearly, stress, inflammation, and obesity are intertwined in a way that we are only beginning to understand.

Click here to read the review by Jin and Flavell, click here to read the study by Siahpush et al, and click here to read the study by Dandona et al.

Cracking Under Stress, photograph © Bernard Goldbach / flickr

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