New research has revealed that obesity reduces the number of taste buds in a study carried out by the scientists of Cornell University. Earlier studies have indicated that Obesity reduces the sensitivity to the taste of food. This is a new dimension, as earlier it was believed that people become obese due to their love of food and find it harder to resist. Obesity, as we all know, has many negative implications on health. But in the current research, inflammatory chemicals associated with obesity are found to reduce the number of taste buds in mice.
What are taste buds?
Taste buds are located on the tongue and have microscopic hairs. Whenever we ingest food, these hairs send messages to the brain about how a particular food tastes. The taste buds comprise 50-100 cells of three different types and responsible for sensing various tastes like salt, sweet, bitter, sour and umami. These buds have rapid turnover and have an average lifespan of 10 days.
In the current study, the team of researchers fed the mice with a normal diet as well as fatty diet. After eight weeks the mice fed with fatty diet gained one third more weight than the mice fed with normal diet. However, to their surprise, there was a 25% reduction in the number of taste buds that were fed with a fatty diet. The turnover of taste buds depends on a balanced combination of apoptosis (programmed cell death) and generation of new cells from progenitor cells. In obese mice, apoptosis was found to be higher than the generation of new cells, and hence there was a decline in the number of taste buds. The team focussed their research on one inflammatory chemical called TNF-alpha which was in higher levels in obese mice. The scientists engineered some mice to be genetically incapable of producing TNF-alpha. To their surprise, they found that there was no reduction in the number of taste buds which clearly indicates that TNF-alpha is the main chemical responsible for the reduction of taste buds.
Researchers plan to check the same phenomenon in humans, even though the physiology if mice and humans are different. But the taste buds might function similarly in both mice and humans.
So, obesity leads to the rise in the inflammatory chemicals leading to the reduction in the number of taste buds and enhances the intake of more calorie-rich foods that further increase obesity. Hence, there repeats a vicious cycle. The Research study is published in PLOS Journal