What if an uncontrollable urge to rapidly eat large amounts of food is rooted in an impaired brain circuit? If that were the case, people who live with binge eating disorder — a psychiatric diagnosis — might be no more at fault for overeating than a patient with Parkinson’s disease
With pulses to their brains, two women’s binge eating went away
One of them, Robyn Baldwin, 58, of Citrus Heights, California, described herself as a “chunko child” who had “always been big”. She tried a wide range of diets. Once, she consumed only protein shakes for a month.
In 2003, she had bariatric surgery, which usually involves altering the digestive system so that the stomach is smaller and food is more difficult to digest. It has enabled many people to lose weight when other methods failed. But for Baldwin, the weight she lost came back.
Lena Tolly, 48, the other patient from the study, lives in Sacramento, California. She also tried a large number of diets and remedies for obesity. Her parents gave her a month at a vegan camp as a graduation present from college. While there, she walked 10 miles (16 kilometres) a day.
In August 2005, Tolly had bariatric surgery. She lost 100 pounds (45.3 kilograms), but the weight crept back on.
“It has to be more than willpower,” she said.
In her case — and in Baldwin’s — it was. Their binge eating is not what most people call bingeing, as when they occasionally start on a bag of chips or a gallon of ice cream and just keep going. Instead, their condition is in the Diagnostic and Statistical Manual of Mental Disorders. It involves bingeing multiple times a week. The binges are accompanied by a feeling of being almost in another state in which they lose all control, quickly consuming large amounts of food. Many, embarrassed by their behaviour, binge in secret. It is common to feel disgust and shame when the binge ends.
The study that Baldwin and Tolly participated in is part of a movement to use deep brain stimulation to treat a variety of disorders that may be caused by problems with electrical signals in the brain. They include movement disorders and psychiatric conditions such as depression and obsessive compulsive disorder, said Dr Edward Chang, a professor of neurosurgery at the University of California, San Francisco, who was not involved in the binge eating study.
Researchers have found precise brain circuits, often in areas just about a millimetre in diameter, that regulate the symptoms of some of these disorders. The discoveries open the way for studies of deep brain stimulation.
Halpern led the pilot experiment with Baldwin and Tolly. But first he and his colleagues began with mice that were prone to obesity. The animals had been fed, but when the researchers put butter in their cage, they devoured it, eating more than 25 per cent of their daily calories in one hour.
The area of their brains that was activated was the nucleus accumbens, a key hub of the brain’s reward centre, located deep in the centre of the brain. In mice, neurons in the nucleus accumbens became active just before a binge. When the researchers used deep brain stimulation to calm those neurons, they were able to prevent the mice from bingeing.
But could it work in humans?
The group of scientists began advertising for people who had regained all their weight after bariatric surgery, believing that it might be due to binge eating disorder.
Baldwin and Tolly replied. Neither realised they had a binge eating disorder. But binge eating is “really, really common in individuals who present for weight loss surgery”, said Lauren Breithaupt, a psychologist at Massachusetts General Hospital who studies eating disorders.
When Baldwin and Tolly met with Halpern, both weighed more than they had before weight loss surgery.
As part of the study, the researchers provided each woman with a 5000-calorie feast of their favourite foods when they were not hungry. The women described the specific emotional triggers that could set off a binge: for Tolly, thoughts of her mother, who had recently died; and for Baldwin, thoughts of her work schedule and responsibilities at home. They agreed to allow the researchers to prompt them to binge with those triggers as part of the study.
The researchers recorded electrical impulses in the women’s nucleus accumbens as they ate, determining that neurons were firing just before the binge and that those electrical impulses were correlated with the women feeling a loss of control. A direct brain stimulator might have been able to intercept the signals and prevent the women from wanting to binge.
After connecting the devices into the women’s brains, the investigators told Baldwin and Tolly that they would activate the devices at some time during the next couple of months but would not tell them when. Both women said they knew immediately when the devices were activated. Suddenly, they no longer felt insatiable eating urges.
Now their weight is slowly coming down. Both say that without actively thinking about it, they are eating differently.
“It’s not self-control,” Tolly said. “I make better choices.” But she hasn’t begun eating foods that never appealed to her. “I am not signing up for kale.”
Baldwin said she noticed a change in her food preferences. She had loved peanut butter and would find herself eating from the jar with a spoon. Now she doesn’t crave it.
“I would get these habits like going into a pharmacy to get a prescription, but I might make a detour to Ben and Jerry’s,” she said.
Once the device was activated, she said, “I could go into the pharmacy and not even think about ice cream.”
She also finds that her tastes have changed. Now her favourite foods are savoury instead of sweet.
“It’s not like I don’t think about food at all,” Baldwin said. “But I’m no longer a craving person.”
But does this show direct brain stimulation can be the answer for people with extreme bingeing?
Breithaupt is cautious.
“It’s just two people,” she said.
This article originally appeared in The New York Times.
Written by: Gina Kolata
Photographs by: Andri Tambunan
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