Wake up and smell the coffee...yes, it's the best way to cure tiredness

But, according to a study, it may be the aroma rather than the coffee itself that does the trick.

Researchers believe that the aroma of roasted coffee beans can soothe frayed nerves  -  and that just the whiff could be enough to reverse the effects of a poor night's sleep on the brain.

Aroma: Just smelling coffee can help cure tiredness better than drinking a cup

They said that chemicals extracted from coffee and pumped into the air may one day be used as a way of reviving tired people.

Scientists in Tsukuba, Japan, kept 16 laboratory rats awake for 24 hours, by keeping them in a cage filled with an inch of water, then exposed half of them to the smell of roasted coffee.

After taking samples of the rats' brains, they found that the smell of coffee boosted the activity of key genes that promote cell survival in the body and reduce anxiety, New Scientist magazine reports today.

Professor Yoshinori Masuo, who led the study in Tsukuba, Japan, said that when people drink coffee to stay up all night, just the smell of the coffee could alleviate some of the stress caused by sleeplessness.

He added: 'Is it better for us to smell coffee bean aroma than to drink coffee, or would any other food-related odour produce similar effects? Further studies are needed.'