A Shocking Way to Cut Calories

Transcranial direct current stimulation tied to reduced calorie consumption


A little shock to the brain could one day help some patients stop overeating.

A new study found that a type of noninvasive brain stimulation called transcranial direct current stimulation (tDCS) may limit the number of calories patients take in.

"Unfortunately, there aren't currently any gold standard brain-based interventions for obesity and weight loss, but we hope that findings from our study will encourage further research in this area," said lead study author Marci E. Gluck, PhD, of the National Institute of Diabetes and Digestive and Kidney Disease, in an interview with dailyRx News.

tDCS uses electricity to stimulate particular brain regions. As shocking as it sounds, it's painless, according to Johns Hopkins Medicine.

For this study, Dr. Gluck and colleagues studied the effects of tDCS on nine obese patients.

Here's what they did: They studied the nine patients for two eight-day periods. For the first five days, the patients ate a prescribed diet that contained enough calories to maintain their weight. Then Dr. Gluck and team applied tDCS to a region of the brain responsible for reward and behavior — the left dorsolateral prefrontal cortex (LDLPFC) — in three 40-minute sessions over three days, but only for some of the patients. The other patients received fake tDCS. None of the patients knew what the researchers were up to.

There are two types of tDCS: anodal and cathodal. Basically, the anodal version is meant to speed up the activity of neurons in the targeted brain region — as opposed to cathodal stimulation, which slows things down. Past research found that obese patients had lower levels of activity in the LDLPFC after eating a meal, Dr. Gluck said. That's why these researchers thought anodal stimulation could have an effect.

After the tDCS sessions, all nine patients were allowed to eat and drink whatever they wanted from vending machines. For the four patients who received fake tDCS, nothing much changed in their eating habits over the three treatment days.

Not so for the patients who received anodal tDCS, however. These patients ate 700 fewer calories on average. That's a healthy chunk of the average eater's daily calorie intake. Cathodal stimulation did not appear to have much effect.

According to these researchers, tDCS might one day be able to help treat obesity, which affects more than a third of US adults, according to a 2014 study in JAMA, and contributes to leading causes of death like type 2 diabetes, cancer, stroke and heart disease.

"The device used to administer tDCS is portable, and if future studies show promising results, this technique could be used outside of a medical setting," Dr. Gluck said. "Just as the light box became a home intervention for treating seasonal affective disorder, tDCS potentially could be used at home to treat weight-related disorders, in combination with regular physical activity and healthy eating. While our findings are promising, more research with larger samples and longer follow-up periods needs to be conducted ..."

So don't get too excited — tDCS is still in its experimental stages, meaning it's not approved for use by the public. But the treatment is promising. It's thought to be safe and would likely be cheaper than current, more invasive forms of brain stimulation, according to Johns Hopkins Medicine. Patients in the current study reported skin redness where the tDCS electrodes had been, Dr. Gluck said.

tDCS has shown promise in other areas, too, including mental health, pain and Parkinson's disease, according to Johns Hopkins.

The study by Dr. Gluck and team was published Nov. 4 in the journal Obesity

The National Institutes of Health, Boston Nutrition and Obesity Research Center, Nutrition Obesity Research Center at Harvard and Center for Nutritional Research Charitable Trust funded this research. The authors disclosed no conflicts of interest.