The study here found that obese mice had about 25 percent fewer taste buds than mice of a healthy weight. As some similar effect is likely found in humans, this research should provide an increased motivation (that is, enjoyment of food) for reducing the obesity epidemic, which I have written about at more length before.
Previous studies have indicated that weight gain can reduce one’s sensitivity to the taste of food, and that this effect can be reversed when the weight is lost again, but it’s been unclear as to how this phenomenon arises. Now a study publishing March 20 in the open-access journal PLOS Biology by Andrew Kaufman, Robin Dando, and colleagues at Cornell University shows that inflammation, driven by obesity, actually reduces the number of taste buds on the tongues of mice.
A taste bud comprises of approximately 50 to 100 cells of three major types, each with different roles in sensing the five primary tastes (salt, sweet, bitter, sour, and umami). Taste bud cells turn over quickly, with an average lifespan of just 10 days. To explore changes in taste buds in obesity, the authors fed mice either a normal diet made up of 14% fat, or an obesogenic diet containing 58% fat. Perhaps unsurprisingly, after 8 weeks, the mice fed the obesogenic diet weigh about one-third more than those receiving normal chow. But strikingly, the obese mice had about 25% fewer taste buds than the lean mice, with no change in the average size or the distribution of the three cell types within individual buds.