A newly-discovered effect of coffee could lead to ways of preventing memory loss in old age. Scientists discovered that the caffeine present in strong coffee alters the brain's electrical activity.
By boosting gamma rhythms, produced by the synchronised firing of nerve cells 40 times a second, it aids memory and learning.
The process involves a brain chemical called adenosine, which is present in especially high levels in the elderly.
When adenosine binds to a molecular receptor on brain cells called A1, it reduces the activity of neurons and lessens the strength of gamma rhythms.
Synchronised nerve cell activity plays a key role in information processing, which is why gamma rhythms increase when people attempt to solve complex mental problems.
Caffeine prevents adenosine binding to the A1 receptor, thereby blocking its effects and boosting gamma rhythms.
Dr Martin Vreugdenhil, from the University of Birmingham, whose team made the discovery, said: "Some people can't get started without a cup of coffee; others need a shot of Red Bull to keep going. Caffeine is by far the most widely used psychoactive drug.
"Research has shown that it increases alertness, cortical activity and speeds up information processing."
The research, which involved testing the effect of caffeine on mouse neurons in the laboratory, was presented at the annual meeting of the Physiological Society at University College London last week.
Dr Vreugdenhil said drinking coffee on a regular basis could increase gamma rhythms up to three-fold because of the way caffeine was concentrated in the brain.
However, he pointed out that too much coffee could have adverse health effects.
"Sleep problems and effects on the heart and blood system caused by caffeine are good reasons to go for decaf and for scientists to attempt to separate the beneficial effects from the side effects," he said. ..SUPL: