Endorphins and Overeating


by Danielle Ofri

As a primary care internist, my practice spans the common adult ailments—diabetes, hypertension, high cholesterol, coronary artery disease, arthritis. It is hard not to avoid the difficult truth that obesity, while perhaps not causing all of these illness, certainly exacerbates them greatly.

With my patients, I stay away from issues of blame—it’s a pointless endeavor and causes unwarranted guilt and shame—but obesity is a critical medical issue that cannot be ignored just because it is difficult to treat.

I’ve always been a bit leery of medications and surgery to “treat” obesity, partly because of their limited efficacy but also because rethinking the way we eat—in the long term—is a cornerstone of good health.

Nevertheless, despite my ongoing discussions about five servings of fruits and vegetables, avoiding soda and fast food, etc, I’ve come to accept that other “treatments” have a role in treatment for at least some patients.

A few of my morbidly obese patients have had good success with bariatric surgery (others, though, have managed to regain all their weight). Despite my reservations, I’m always interested in learning about new treatments, and a study in a recent issue of the Lancet caught my eye. This study intrigued me on a personal level because it centered on the endorphin (the biochemistry of which was the basis of my doctoral dissertation many moons ago).

Endorphins and enkephalins are the body’s natural opiate-like compounds, involved in pain regulation, addiction, “runner’s high,” and emotions, among other things. Some animal studies have a suggested a link between endorphins and eating behavior.

In a multi-center trial, 1,742 obese adults were randomized to placebo or a combination of naltrexone (an endorphin blocker) and buproprion (an antidepressant that also helps nicotine addiction). The goal was to lose at least 5 percent of body weight at the end of a year of treatment.

In the placebo group, 16 percent achieved the goal. In the naltrexone/buproprion groups (they tested two doses) 39-48 percent achieved the goal.

This is an interesting study that I believe offers some promise, though there are, of course, important limitations. The treatment group had more side effects (stomach upset, dizziness, dry mouth). Most significantly, there is no information beyond one year, and we all know that maintaining weight loss is a lifelong endeavor.

Naltrexone and buproprion are not yet ready to be prescribed for weight loss—further studies are needed, and FDA approval for this indication is important—but this is certainly an intriguing and thought-provoking study.

(from CNN)