The research could have implications for restaurateurs

But labelling an unpleasant smell with a more appealing name can improve its aroma, an Oxford University team has found.

In an experiment, volunteers asked to smell a cheddar cheese odour rated it as more pleasant when it was labelled as "cheddar" than as "body odour".

A label was enough to make them imagine a smell even when they were sniffing clean air, the journal Neuron reports.

Word power

Professor Edmund Rolls and his team scanned the volunteers' brains while they were smelling the test aromas to see what was going on within the brain.

When the cheddar cheese smell was labelled correctly, higher areas of the brain that interpret smells were activated.

How you describe your food could potentially have an important influence on how you perceive it

Professor Rolls

Clean air labelled as cheddar cheese activated the same areas, but to a lesser extent.

But when the cheddar cheese smell or the clean air was labelled as body odour there was no activity in this brain area.

The researchers also checked whether how big a sniff the person took might change the results, which it did not.

Pleasantness of odour

Professor Rolls said: "A word label in our experiment actually influenced the sense of perception of an odour.

"It's the pleasantness of the odour that is being modulated in a part of the brain called the orbito-frontal cortex, which is involved with emotions.

Vieux Boulogne is thought to be one of the smelliest cheeses in the world

"That high level influence descends down into the olfactory system."

He said the findings could be important for understanding both health and disease.

For example, the orbit-frontal cortex is often damaged in dementia and in people who have had road traffic accidents.

Sometimes, these people have altered appetites as a result that can make them prone to obesity, said Professor Rolls. He said impaired smell processing might be linked to this.

"Of course there is also a consumer side to this. For example, people interested in creating wine and restaurateurs.

"How you describe your food could potentially have an important influence on how you perceive it."

Tim Jacob from the smell research laboratory at Cardiff University said: "Smell is a very special sense.

"It activates systems in the brain which are subconscious.

"Memory has a major impact on smell and we are very suggestible.

"Perfume companies have surveyed potential customers on the smell of perfumes in different coloured and shaped bottles.

"And people think it is a different perfume just because it is in a different bottle even though it is the same smell."