Coffee’s boost of energy, wakefulness could be Placebo

Lausanne: The act of drinking a cup of coffee might wake people up more than just plain caffeine, scientists said in a new study, but it isn't fully clear as to why.

The study, published in Frontiers in Behavioral Neuroscience, looked at whether coffee drinkers' alertness came from the caffeine itself or the experience of drinking the beverage.

Scientists in Portugal recruited people who had at least one cup of coffee a day, asking them not to eat or drink anything caffeinated at least three hours before the study.

They interviewed them, before carrying out two MRI scans: one before and one 30 minutes after drinking a cup of coffee.

Researchers told participants to let their minds wander.

The MRIs, as expected, showed higher brain function in terms of executive memory, introspection and self-reflection processes. However, they also highlighted faster responses when it came to working memory, cognitive control and goal-directed behaviour.

For those in the study just taking caffeine, this didn't happen.

“Taking into account that some of the effects that we found were reproduced by caffeine, we could expect other caffeinated drinks to share some of the effects,” Dr. Maria Picó-Perez of Jaume I University, first author.

He added, “However, others were specific for coffee drinking, driven by factors such as the particular smell and taste of the drink, or the psychological expectation associated with consuming that drink.”

There are still more questions to answer, as scientists didn't look at non-coffee drinkers or test withdrawal effects.

"Another limitation of the current study relates to the fact that we have only studied resting-state brain connectivity," the paper said. "And further studies should also address the impact of coffee/caffeine in task-related events, which are certainly more insightful in the establishment of psycho-cognitive effects of coffee intake and in the discrimination of differences in the patterns of responses to caffeine by habitual consumers and habitual non-consumers."