In today’s Academic Minute, Dr. Kathryn Medler of the University at Buffalo explains why sweets can be experienced differently by people of different weights.
Kathryn Medler is an associate professor in the Department of Biological Sciences at the University at Buffalo. Her lab seeks to understand how signaling mechanisms are regulated within taste cells and how this regulation impacts the generation of the stimulus signal to the brain.
Dr. Kathryn Medler - Obesity and Tasting Sugar
As a biologist, I’ve been intrigued by taste for a long time. Food plays such a huge role in our lives, from the sugary donuts that we munch in the morning, to the savory chicken soups that keep us warm when we’re sick. And yet, compared with our other sensory systems, we actually know very little about taste.
My latest research looks at one important topic in this field: How taste is linked to obesity, a health problem that affects one in three adults in the United States. Previous studies have shown that obesity can lead to changes in the brain and the nerves that connect it with the tongue. But no one had ever looked at the taste cells that make contact with food, so that’s where I decided to focus my work.
We ran an experiment on 50 mice: 25 normal mice, and 25 of their littermates who ate a high-fat diet and became obese. The two groups of animals had different perceptions of the same foods. Specifically, the obese mice had trouble detecting sweetness. They had fewer taste cells that responded to sweet stimuli, and the cells that did respond reacted weakly. This means that the very first element in the taste pathway — the cells on the tongue — are affected by obesity.
We can’t say for sure how a dulled sense of sweetness encourages weight gain, but we do know that taste helps regulate appetite. If something is salty or sweet, we will want to eat more of it than if it were bitter. Taste dictates what we consume — and how much of it. It’s possible that obese mice have to eat more sweets to get the same satisfaction as the regular mice whose cells are more sensitive.