NEW YORK – Junk food has long been linked to obesity, but a new study shows it could also destroy a person’s sense of smell.
Researchers found that a high-fat diet is linked to major structural and functional changes in the nasal system.
Experiments carried out on mice found those on a high-fat diet were less able to recognise a particular odour after losing 50 per cent of the brain cells that recognise the signals.
The findings, published in the Journal of Neuroscience, show diet may impact a range of human traits apart from weight.
Dr Nicolas Thiebaud, of Florida State University, said: ‘This opens up a lot of possibilities for obesity research.’
It is the first time researchers have been able to demonstrate a firm link between a bad diet and a loss of smell.
In the six-month study mice were given a high-fat daily diet, while also being taught to associate between an odour and a reward of a drink of water.
Mice given the food were slower to learn the association than a control group given their usual meals.
And when researchers introduced a new fragrance to monitor their adjustment, the mice with the high-fat diets could not rapidly adapt, demonstrating reduced ability to smell.
Fellow researcher Professor Debra Ann Fadool said: ‘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 – they still had reduced olfactory [smell] capacities.
‘Mice that were exposed to high-fat diets just had 50 per cent of the neurons that could operate to encode odour signals.’
The team will now begin looking at whether exercise could slow down a high-fat diet’s impact on smell.
They will also investigate if a high-sugar diet would also have the same negative effect.