Coffee was given to rats in the study

Scientists from Southwestern University found caffeine increased the female libido in experiments on rats.

The Pharmacology, Biochemistry and Behaviour journal study said the effect was caused by it stimulating the part of the brain regulating arousal.

But researchers said a similar effect was only likely to be repeated in humans who do not drink coffee regularly.

Previous research has looked into both the health benefits and consequences of coffee consumption.

Humans would have to drink 10 cups of coffee in one go to get the same effect and that is not the normal consumption level

British Coffee Association spokesman

The hot drink is linked to improving memory and reducing the risk of cancer, but studies have also suggested it increases the risk of heart disease.

In the latest research, scientists gave 108 female rats a moderate dose of caffeine before a mating test to determine if the caffeine had any effect on female behaviour.

They found that administration of caffeine shortened the amount of time it took the females to return to the males after sex for another mating session.

The study said the effects appeared to go beyond a simple boost of energy for socialising, but researchers said the effect may not be repeated in all humans.

Brain

Lead researcher Dr Fay Guarraci said: "These rats had never had caffeine before. In humans, it might enhance the sexual experience only among people who are not habitual users."

But she added the study should help improve understanding about the relationship between the brain and behaviour.

"Understanding the circuits that control this behaviour will help us understand how the brain works and what part of the brain mediates motivation because sexual behaviour is a motivative behaviour."

But a spokesman for the British Coffee Association said: "We are not that convinced by this. Humans would have to drink 10 cups of coffee in one go to get the same effect and that is not the normal consumption level.

"There are health benefits of coffee, but at this stage I do not think we can include this as one."