We’ve all been there — telling ourselves we’ll only eat half the mountain of fries that accompany a burger on our restaurant plate. Yet by the end of the meal with bellies bursting, all the fries are mysteriously gone.
Whether its fries or ice cream or that box of Girl Scout cookies, scientists think they’ve found a clue to why humans binge eat. The discovery, published in the journal Science, was made by a team at Yale University School of Medicine that was researching a common surgical procedure used to offer people with Parkinson’s disease relief from symptoms.
Deep-brain stimulation, known as DBS, targets an area of the brain called the subthalamic nucleus with high-frequency electrical pulses that disrupt activity of neurons. It’s meant to mitigate Parkinson’s symptoms like rigidity and tremors, but scientists have found it can also have a negative impact of causing binge eating.
The National Eating Disorders Association characterizes binge eating as recurrent episodes of eating large amounts of food, generally in a short amount of time and to the point of uncomfortable fullness. Other symptoms include losing control during a binge and having shame or guilt after binging.
It is the most common eating disorder in the U.S., more than three times more common than anorexia and bulimia combined. According to NEDA, a 2007 study showed 3.5 percent of women and 2 percent of men had a binge eating disorder. If often begins in late teens and early 20s, but can be found in people of all ages.
The Yale researchers experimented on mice on a specific part of the brain circuitry that can be turned on and off to see if they could identify how the brain controls binge eating. They found that accessing a particular portion with laser pulses allowed them to activate neurons that immediately caused mice to binge eat. In only 10 minutes, the mice ate a third of their daily food.
In mice where scientists kept stimulating those neurons four times 30 minutes apart, mice craved fatty foods and gained weight by eating around 75 percent of their daily food. Mice that received no treatment ate less than 25 percent of their food at one time.
Scientists hope that the findings translate to people. If so, identifying why the Parkinson’s treatment causes overeating could also help those without that disease that suffer from binge eating disorder.