High-fat diet linked to loss of olfactory function

Eating a high-fat diet could lead to a loss of smell, according to Florida State University neuroscientists. The researchers found that a high-fat diet is linked to major structural and functional changes in the olfactory system.

The finding has researchers looking more closely at how diet could impact a whole range of human functions that were not traditionally considered when examining the impact of obesity.

Over a six-month period, researchers fed mice a high-fat diet while teaching them to associate between a particular odour and a reward.

The mice on the high-fat diets were slower to learn the association than the control mice. The researchers also found that when they introduced a new odour to monitor their adjustment, the mice on the high-fat diet could not rapidly adapt, demonstrating reduced smell capabilities.

“Moreover, when high-fat-reared mice were placed on a diet of controlled chow during which they returned to normal body weight and blood chemistry, they still had reduced olfactory capabilities,” said Professor Debra Ann Fadool, co-author of the paper outlining the research.

“Mice exposed to high-fat diets only had 50% of the neurons that could operate to encode odour signals.”

Lead researcher Nicolas Theibaud and his colleagues will now begin looking at whether exercise could slow the impact of a high-fat diet on smell and whether a high-sugar diet has similar impacts on smell as a high-fat diet.

The research is published in the Journal of Neuroscience.