Brain Stimulation Could Limit the Urge to Binge Eat, Study Says

Brain Stimulation Could Limit the Urge to Binge Eat, Study Says

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 is for their tremors.

That question led doctors to try a new treatment different from anything ever attempted to help people with this common but underreported eating disorder. At least 3 percent of the population has it, said Dr. Casey Halpern, a neurosurgeon at the University of Pennsylvania.

He and his colleagues decided to try deep brain stimulation, a method routinely used to quell tremors in patients with Parkinson’s. It involves placing electrodes in the brain to regulate aberrant signals. The wires, connected to the electrodes, are placed under the scalp, where they are invisible and unobtrusive. For the binge eating treatment, the device only stimulates neurons when the device detects a signal to start a binge.

The pilot study, funded by the National Institutes of Health and published earlier this year in the journal Nature Medicine, involves two women and will be expanded in a few months to include four more people living with binge eating disorder who regained the weight they lost after bariatric surgery. Before the treatment can be approved by the Food and Drug Administration, researchers will need to rigorously test the method in at least 100 people in multiple medical centers. Such a study would take several years to complete.

The two women whose devices were implanted a year ago will be followed for up to three years. They had the option to have their devices removed after 12 months, but both wanted to keep them because they no longer felt irresistible urges to binge.

One of them, Robyn Baldwin, 58, of Citrus Heights, Calif., 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 Ms. Baldwin, the weight she lost came back.

Lena Tolly, 48, the other patient from the study, lives in Sacramento. 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 a day.

In August 2005, Ms. Tolly had bariatric surgery. She lost 100 pounds, but the weight crept back on.

“It has to be more than willpower,” she said.

In her case — and in Ms. Baldwin’s — it was. Their binge eating is not what most people call binging, as when they occasionally start on a bag of chips or on a gallon of ice cream and just keep going. Instead, their condition is in the Diagnostic and Statistical Manual of Mental Disorders. It involves binging 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 behavior, binge in secret. It is common to feel disgust and shame when the binge ends.

The study Ms. Baldwin and Ms. 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 millimeter in diameter, that regulate the symptoms of some of these disorders. The discoveries open the way for studies of deep brain stimulation.

Dr. Halpern led the pilot experiment with Ms. Baldwin and Ms. 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 percent 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 center, located deep in the center 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 binging.

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.

Ms. Baldwin and Ms. Tolly replied. Neither realized 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 the Massachusetts General Hospital who studies eating disorders.

When Ms. Baldwin and Ms. Tolly met with Dr. Halpern, both weighed more than they had before weight loss surgery.

As part of the study, the researchers provided each woman with a 5,000-calorie feast of their favorite foods when they were not hungry. The women described the specific emotional triggers that could set off a binge: for Ms. Tolly, thoughts of her mother, who had recently died; and for Ms. 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 Ms. Baldwin and Ms. 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,” Ms. 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.”

Ms. 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 favorite foods are savory instead of sweet.

“It’s not like I don’t think about food at all,” Ms. 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 binging?

Dr. Breithaupt is cautious.

“It’s just two people,” she said.

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