Research has linked newly-identified brain circuitry to both the experience of stress and the desire to eat. This finding has surprised scientists, but I can personally vouch for the depressive effect of stress on appetite. But then, there’s the well-documented fact that stress makes some folks eat more…
How often have you heard overweight people complain, “I eat when I’m stressed out, and I get stressed out when I eat.” That relationship between stress and the desire to eat officially remains unexplained by science, but millions of people around the world can attest that it’s more than a simple delusion.
However, researchers at the University of Texas Health Science Center in Houston say they’ve identified a brain circuit that may explain why, in many folks, feeling stressed depresses the desire to eat.
What they did
A team of researchers led by Study Lead Author Dr. Qingchun Tong conducted mouse-level experiments to obtain basic evidence about whether their main supposition had a basis in fact. They focused on a neurocircuit connecting two parts of the mouse brain (which is in many ways is very similar to ours): the paraventricular hypothalamus, an eating-related zone in the brain, and the ventral lateral septum, an emotional zone in the brain.
What they found
The neurocircuit acts as an on/off switch. When researchers activated the neurocircuit, there was an increase in anxiety levels and a decrease in appetite. Conversely, when the investigators inhibited the neurocircuit, anxiety levels dropped and hunger increased.
“We have identified a part of the brain in a mouse model that controls the impact of emotions on eating,” said Tong.
The takeaway
The scientists believe their research could aid efforts to develop treatments for anorexia nervosa, which has the highest mortality rate of any mental disorder, according to the National Institute of Mental Health. People with anorexia nervosa (see photo, left) avoid food, severely restrict food, or eat very small quantities of only certain foods. Even when they are dangerously underweight, they may see themselves as overweight.
My take
But what about the folks who say, “‘I eat because I’m unhappy, and I’m unhappy because I eat’? To be fair, I’ll allow that’s a separate issue for another day.
Since the activation-deactivation of the brain circuit produces opposite results, I’m frankly more interested in how the mechanism could be used to curb the desire to eat in overweight or obese subjects. The researchers don’t say anything about that in their Study. I guess it’s ethically wrong to propose that people should be made to suffer stress to get the benefits of the other side of the on/off switch. But why not conduct some experiments about how the hunger part of the brain circuit can be turned on or off without effecting the stress part? Obesity is a much bigger and widespread problem than anorexia nervosa…
~ Maggie J.