There may be more to the term comfort eating than we realize – however, consuming fat appears to be the mood-lifter, rather than any other food ingredient. Researchers from University of Leuven, Belgium, reported on a study in the Journal of Clinical Investigation.

The authors explained that humans have an intimate relationship between their emotional state and what they eat. When we feel tired, stressed, anxious or overworked we tend to grab the chocolate bar, rather than an apple – in other words, comfort foods.

Lukas Van Oudenhove, MD., PhD. and team charted areas of the brain with functional magnetic resonance imaging (MRI) scans – specific areas of the brain are seen to light up when a person is sad. They recruited 12 healthy individuals, none of them was obese. They were then given an infusion of fatty acid or saline via a feeding tube.

Fatty acid was used because most comfort foods have a high fatty acid content.

The healthy individuals listened to music, which was either sad or neutral. They also looked at images of the same nature (sad or neutral). They provided feedback on their state of hunger, fullness, and mood before the imaging scan, and also three times during it.

When the infusion was administered, the participants did not know whether they were receiving saline or fatty acid.

The researchers found that the levels of sadness among the fatty acid receivers was approximately 50% lower compared to the saline receivers. The authors wrote:

“These findings increase our understanding of the interplays among emotions, hunger, food intake and meal-induced sensations in general which may have important implications for a wide range of disorders including obesity, eating disorders, and depression.”

Co-author, Giovanni Cizza, MD., believes that the gut must be talking to the brain in some way. If scientists can identify what is going on, there might be a potential for new drug developments, the scientists believe.

Dr. Giovanni said:

“We did not know if you put fat in the stomach without pleasant stimulus, it could modulate our emotions,” he says. “There must be a way in which the gut talks to the brain.

The areas of the brain that get activated or suppressed as a result of emotion and mood were impacted by fatty acid emulsion. These fats reduced some of the emotion or neural changes, and this is a phenomenon that many patients have described.

Many things in obesity have been said to be psychological and this adds to the body of evidence that something physical is going on. “

As this study focused purely on individuals who are not obese, the researchers wonder whether the effects may be more pronounced in those who are overweight or obese.

“Fatty acid-induced gut-brain signaling attenuates neural and behavioral effects of sad emotion in humans”
Lukas Van Oudenhove, Shane McKie, Daniel Lassman, Bilal Uddin, Peter Paine, Steven Coen, Lloyd Gregory, Jan Tack and Qasim Aziz
J Clin Invest. doi:10.1172/JCI46380.

Written by Christian Nordqvist