Obesity: A Deficiency of the CRTC1 Gene Can Lead to Cravings for Fatty and Sweet Foods

Fatty and sweet foods tend to be very addictive, and for many people, they are hard to give up. According to Japanese researchers, this irresistible urge to overeat is caused by an active gene in the neurons. Studying how it works could help us better understand the genetic origins of obesity.

Obese Woman

Eating too much high-calorie, high-fat and high-sugar food can lead to obesity. But where does that irresistible urge to eat those delicious chocolate chips and fried cheeseballs come from? Japanese researchers from Osaka Metropolitan University have looked at our genes, in particular the CRTC1 gene, which is known to be linked to obesity in humans. Is it responsible for us being drawn to these types of foods?

CRTC1 a gene that controls gluttony

In mice, the absence of CRTC1 makes the rodents obese. Researchers, therefore, believe that this gene, which is expressed by neurons in the brain, prevents obesity. The mechanisms involved are not yet known. To understand this, the Japanese researchers studied a population of neurons called MC4R – which expresses the MC4R gene, another genetic factor for obesity – using genetically modified mice that normally express the CRTC1 gene, except in the population of MC4R neurons, where it is repressed.

This allows for the study of the effect of CRTC1 loss on obesity and diabetes. When the modified mice were fed normally, they showed no problems with obesity, but when fed a high-fat diet, they became insatiable, obese, and diabetic.

What the study showed

This study has revealed the role of the CRTC1 gene in the brain and part of the mechanism that prevents us from eating high-calorie, high-fat and high-sugar foods. “We hope this will lead to a better understanding of why people overeat,” said Professor Shigenobu Matsumura, lead author of the study published in The Faseb Journal. Overeating is just one aspect of obesity; this complex disease has multiple causes, ranging from psychological to genetic and hormonal. These findings are a first step towards understanding this phenomenon in humans and its role in the development of obesity.