Why does coffee wake us up? Is it because it contains caffeine, or is it because we are used to it waking us up after drinking it? A study published on Heliyon on January 30, 2025 attempted to answer this question. Researchers found that habitual coffee drinkers may develop conditioned responses, where the mere act of consuming coffee triggers physiological changes regardless of whether caffeine is actually present. Also read | Fitness coach says ‘if you drink coffee every morning you are technically doing drugs on a daily basis’: But is it true?

Is it the caffeine or could it be the ritual itself?

Effects of caffeine on the human body are intensely researched, though pros and cons of caffeine are still debated. But the new study’s findings suggest that regular coffee consumers may react to the experience of drinking coffee in ways that are independent of its caffeine content.

“Caffeine is something we use everyday, yet is poorly understood, and thus makes an inviting study subject. We wanted to understand what actually triggers the physical and mental effects people associate with coffee, especially in regular drinkers,” said study author Mateja Lesar.

More about the study

For their study, the researchers designed a controlled experiment focused on separating the effects of caffeine from the psychological and physiological effects of the coffee-drinking ritual. They recruited 20 habitual coffee drinkers, who received either caffeinated or decaffeinated coffee (placebo) in a double-blind, randomised fashion. The two substances were identical except for the presence of caffeine.

The researchers measured cognitive performance, cardiovascular responses, and whole-head EEG during rest and during an auditory-oddball task. The same measurements were done before and after ingestion. 

The researchers said they expected to find significant differences between caffeine and placebo groups across the outcome measures. However, except for the resting-state alpha power, changes due to ingestion in physiological responses and cognitive functioning were not significantly different between the two groups.

Actually, only one of the three cognitive measures was found to be significantly altered by the ingestion, they said. These findings suggest that regular coffee consumers respond to coffee-like beverages independently of the presence of caffeine.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.