Researchers in the Hotchkiss Brain Institute at the University of Calgary’s Faculty of Medicine have solved the riddle of why some people turn to food in stressful times. They discovered a mechanism by which stress increases food drive. Stress temporarily rewires nerve cells in the brain to increase hunger. A study of rats conducted by Quentin Pittman and an Indian-origin researcher Jaideep Bains found stress increases food drive and can trick the brain into thinking the body is still hungry when it’s not. This new discovery can provide important insight into why stress is considered to be one of the underlying contributors to obesity.

The brain produces neurotrans- mitters, chemicals responsible for communication of cells in the brain, called endocannabinoids. It sends signals to control appetite. The researchers found that when food is not present, a stress response occurs. It temporarily causes a functional re-wiring in the brain. This re-wiring impairs the endocannabinoids’ ability to regulate food intake and enhance the food taking. Since a lack of food causes the stress which, in turn, causes the disturbance of food-intake regulators. When the researchers blocked the effects of stress hormones in the brain, the absence of food caused no change in the neural circuitry.

Researchers looked specifically at nerve cells (neurons) in the region of the brain called the hypothalamus. This structure is known to have an important role in the control of appetite and metabolism. It has been identified as the primary region responsible for the brain’s response to stress. Their findings can help to explain how the cellular communi- bcation in our brains is overridden in the absence of food. According to researchers these changes are driven not by the lack of nutrients, but by the stress made by the lack of food.