The research, presented last week at the annual meeting of the Physiological Society, suggests that an effect of caffeine could be key to enhancing memory performance in the elderly.
This new result will be seen as good news to the coffee, tea and energy and stimulant drinks industries. A Mintel report showed that energy and stimulant drink sales were set to exceed £1bn (€1.45bn) in the UK in 2005, with a 75 per cent increase in sales volume since 2000.
"Some people can't get started without a cup of coffee; others need a shot of Red Bull to keep going. Research has shown that it increases alertness, cortical activity and speeds up information processing," said lead researcher Dr Martin Vreugdenhil.
Indeed, previous studies has shown how caffeine might be enhancing memory, in that it binds to brain receptors, blocking the calming effect of the adenosine neurotransmitter.
Adenosine levels in the brain increase during the day and are especially high in the elderly. When adenosine binds to a so-called A1 receptor it decreases activity of nerve cells, but when it binds to an A2a receptor it boosts activity.
The University of Birmingham researchers found that caffeine can boost so-called gamma rhythms by more than three times its normal value, according to the results of a study performed with mice brains.
Nerve cell activity in the brain is synchronized in a rhythmic fashion at a frequency of about 40 times a second, and is said to increase when we need to solve complication problems, for example.
Using slices of mouse hippocampus, the researchers measured gamma oscillations in the samples in the presence and absence of caffeine (50 micromoles). Compared to the control samples, it was found that the caffeine increased these oscillations by 332 per cent, said the researchers.
This effect was indicated to be due to a selective blocking of the A1 receptor.
These results suggested that caffeine concentrations in the brain resulting from a few cups of coffee could significantly increase gamma rhythm strength, which is likely to contribute to the cognitive beneficial effects.
Worldwide daily caffeine consumption averages one and a half cups, while the US average is more than three and a half cups.
But the Birmingham researchers found that at higher concentrations of caffeine the effect appeared to be slightly reduced.
Moreover, Dr. Vreugdenhil warned against drinking excessive amounts or very strong coffee: "Sleep problems and effects on the heart and blood system caused by caffeine are a good reason to go for decaf and for scientists to attempt to separate the beneficial effects from the side effects. This is a critical step in our research efforts."
Coffee, one of the world's largest traded commodities produced in more than 60 countries and generating more than $70bn in retail sales a year, continues to spawn research and interest, and has been linked to reduced risks of certain diseases, especially of the liver and diabetes.