"This opens up a lot of possibilities for obesity research," said Florida State University post-doctoral researcher Nicolas Thiebaud, who led the study examining how high-fat foods impacted smell.
Thiebaud led the study in the lab of Biological Science Professor Debra Ann Fadool. Their work is published in the Journal of Neuroscience
and shows that a high-fat diet is linked to major .
It was the first time researchers had been able to demonstrate a solid link between a bad diet and a loss of smell.
The research was conducted over a six-month period where mice were given a high-fat daily diet, while also being taught to associate between a particular odor and a reward (water).
Mice that were fed the high-fat diets were slower to learn the association than the control population. And when researchers introduced a new odor to monitor their adjustment, the mice with the high-fat diets could not rapidly adapt, demonstrating reduced smell capabilities.
"Moreover, when high-fat-reared mice were placed on a diet of control chow during which they returned to normal body weight and blood chemistry, mice still had reduced olfactory capacities," Fadool said. "Mice exposed to high-fat diets only had 50 percent of the neurons that could operate to encode odor signals."
For Thiebaud and his colleagues, the results are opening up a whole new line of research. They will begin looking at whether exercise could slow down a high-fat diet's impact on smell and whether a high-sugar diet would also yield the same negative results on smell as a high-fat diet.
Funded by the National Institutes of Health (NIH), the study comes at an important time with obesity rates at all-time highs throughout the world. According to the NIH, more than two in three adults in the United States are considered to be overweight or obese. Additionally, about one-third of children and adolescents ages 6 to 19 are considered to be overweight or obese.