The hormone oxytocin plays a role in intimacy, sexual reproduction, and bonding during and after childbirth. A new study finds that a synthetic nasal formulation of the hormone lowered calorie consumption in healthy men, especially fatty foods, after a single treatment.

The results confirm earlier animal studies that show oxytocin reduces food intake. They may also indicates further correlation between stress, stress hormones, and consumption of carbohydrate heavy foods.

The oxytocin nasal spray, manufactured by Novartis, is approved in Europe but not in the U.S. except for clinical trials. In the U.S., oxytocin is available as an intravenous or injectable drug, known as Pitocin, for inducing labor.

Lead investigator Elizabeth Lawson, MD, MMSc, of medicine at Harvard Medical School, said:

“Our results are really exciting. Further study is needed, but I think oxytocin is a promising treatment for obesity and its metabolic complications.”

The nasal spray lowered the number of calories men ate at a subsequent breakfast, whether they were normal weight, or overweight. The researchers also found that oxytocin improved metabolic measures, like insulin sensitivity, the body’s ability to clear sugar from the bloodstream.

On average, the men in the study consumed 122 fewer calories, and 9 grams less fat, at the meal after they received oxytocin nasal spray compared with placebo. Oxytocin also was reported to have increased the use of body fat as a fuel for energy.

No serious side effects and no difference in side effects between oxytocin and placebo were seen, according to Lawson. Since oxytocin has gender-specific effects, it needs to be studied seperately in women, as well as in both sexes for an extended treatment duration, she said.

An earlier German study from 2013 showed similar results, and in that study, oxytocin reduced snack consumption of chocolate cookies by 25%.

Lawson EA1, Marengi DA, DeSanti RL, Holmes TM, Schoenfeld DA, Tolley CJ Oxytocin reduces caloric intake in men Obesity 2015 May;23(5):950-6. doi: 10.1002/oby.21069

Photo: april/flickr

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