Caffeine only makes you alert, coffee makes you 'ready to go', say scientists

New Delhi: If you want to feel not just alert but ready to go, caffeine alone won't do - you need to experience that cup of coffee, say scientists after studying the effects of coffee vs caffeine in coffee-drinkers.

The scientists wanted to understand if the wakefulness effect came from caffeine or from the experience of drinking coffee.

"There is a common expectation that coffee increases alertness and psychomotor functioning," said Nuno Sousa of the University of Minho, Portugal, and corresponding author of the study published in the journal Frontiers in Behavioral Neuroscience.

"When you get to understand better the mechanisms underlying a biological phenomenon, you open pathways for exploring the factors that may modulate it and even the potential benefits of that mechanism," said Sousa.

The scientists recruited people who drank a minimum of one cup of coffee per day and asked them to refrain from eating or drinking caffeinated beverages for at least three hours before the study.

The participants' sociodemographic data was collected through interviews and their brains were scanned using functional MRI (fMRI), once before and once 30 minutes after taking caffeine or drinking a standardised cup of coffee.

While being scanned, the participants were asked to relax and let their minds wander.

Being aware of the neurochemical effects of drinking coffee, the scientists expected the brain scans to show an increased integration of the prefrontal cortical networks associated with executive memory and of the default mode network involved in introspective and self-reflective processes.

However, in both coffee-drinkers and caffeine-takers, they found that the introspection network's connectivity had decreased, suggesting that both coffee and caffeine consumption made people more active and more prepared for working on tasks.

Also, only in coffee-drinkers, the scientists established an enhanced connectivity in brain regions accessed for working memory, cognitive control and goal-directed behaviour - the higher visual network and the right executive control network.

That this didn't take place in caffeine-takers suggested, scientists said, that if you want to feel not just alert but ready to go, caffeine alone won't do - you need to experience that cup of coffee.

"In simple words, the subjects were more ready for action and alert to external stimuli after having coffee," said Maria Pico-Perez of Jaume I University, Spain, and the study's first author.

"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," added Pico-Perez.

"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," said Pico-Perez.