29 Jul 2017

Is our sense of smell making us fatter?

From This Way Up, 12:55 pm on 29 July 2017
obese women

Photo: AFP

Could our sense of smell be an important factor behind the fact that so many of us are overweight?

A study on mice found that those that had their sense of smell neutralised would lose weight even though they were eating exactly the same number of calories and doing the same amount of exercise as mice with their sense of smell intact.

Ablation of olfactory neurons in the nose using a genetic method, on the right this is the mouse without smell (the red neurons are ablated) compared to its control.

Ablation of olfactory neurons in the nose using a genetic method, on the right this is the mouse without smell (the red neurons are ablated) compared to its control. Photo: (Supplied)

The researchers think that smell is linked to the mices' metabolism: take it away and the mice will burn more calories. On the other hand they found that 'super smellers', animals genetically engineered to be extra-sensitive to odours, would burn fewer calories, store them as fat, and became obese.

Although it's still early days and this is just a study on mice, the findings raise the intriguing prospect of manipulating our sense of smell to control how much energy we use: for example a spray used to knock out our sense of smell for a few hours could prompt our bodies to burn more calories and lose weight. Now that sounds like our kind of diet!

Mice on high fat diet, the one with loss of smell remains lean

Mice on high fat diet, the one with loss of smell remains lean Photo: (Supplied)