High-fat diet may hurt sense of smell

Stuffing yourself with high-fat foods may not only expand your waistline, it may also cause you to lose your sense of smell, a new study suggests.
Florida State University neuroscientists have for the first time demonstrated a solid link between a bad diet and a loss of smell.
The study led by post-doctoral researcher Nicolas Thiebaud in the lab of Biological Science Professor Debra Ann Fadool found that a high-fat diet is linked to major structural and functional changes in the olfactory system, which gives us our sense 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 odour 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 odour 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 per cent of the neurons that could operate to encode odour signals," Fadool added.
Researchers will now look 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.

The study is published in the Journal of Neuroscience.