Sugar provides necessary energy in the human diet, but excess sugar consumption is associated with weight gain and metabolic disorders. The average person living in the United States consumes approximately 100 pounds of sugar per year. Findings from a recent study suggest that our preference for sugar has its origins in the brain.

The authors of the study gave mice water that was sweetened with either sugar or acesulfame, an artificial sweetener commonly used in diet drinks and foods. At first, the mice chose to drink both solutions, but after two days, the mice chose the sugar-sweetened water only.

The researchers analyzed the brain activity of the mice when they drank the two solutions and found that a particular region of the brain responds to sugar – an area called the caudal nucleus of the solitary tract, which is located in the brain stem. They discovered that signals originating in the gut travel along the vagus nerve to this region of the brain to create a gut-brain-axis specific to glucose and similar molecules. Intake of these molecules stimulates even greater consumption, setting up an environment conducive to overconsumption.

Identification of this neural pathway provides insights into human consumption of sugar and might inform the development of new strategies to reduce intake.

• Link to full study.

• Listen to this podcast in which Dr. Rhonda Patrick discusses some of the effects associated with sugar consumption.