It appears that the caffiene fix many coffee addicts can't possibly do without may be all in the mind.

University of East London researchers studied 88 volunteers aged between 18 and 47 who were self-confessed coffee lovers, downing at least two cups every day.

Some were given caffeinated coffee and told it was decaffeinated. Others were given decaffeinated but were told it contained caffeine.

The researchers found that volunteers led to believe that the decaf coffee they were drinking actually contained caffeine noticed a significant improvement in performance and mood in their test subjects.

In tests that were designed to measure reaction times, mental performance and mood some even did better than volunteers who had consumed coffee with caffeine.

It turns out that the legendary pick-me-up powers of the coffee bean may be at least partly due to consumers anticipating a caffeine hit and feeling its effects even when there were none, the researchers said.

Some studies have suggested that three cups of coffee a day can significantly reduce the risk of Alzheimer's disease, possibly by triggering a chain reaction in the brain that prevents the damage done by the disease.

According to the British Coffee Association, British consumers drink approximately 70 million cups a day.