A recent study has uncovered how coffee can impact your brain even when you're in bed. According to a study published in Neuron (May 2025), caffeine, which is present in coffee, can interrupt your brain's internal sleep cycles in ways you may not anticipate.
Researchers at the University of Basel in Switzerland examined how caffeine impacts the brain's electrical activity while you're sleeping. They discovered that even when you sleep after having a cup of coffee, your brain fails to receive the restful sleep it requires. Brain scans indicated that caffeine inhibits adenosine, a chemical that induces sleepiness. Without adenosine functioning, the brain remains more alert, even when you're sleeping.
One of the shocking surprises? The impact isn't only temporary. Habitual coffee consumers can gradually alter their brain's sleep pattern. This can result in lighter sleep and poorer sleep quality in the long term. Even consuming coffee six hours before going to bed can decrease deep sleep by over 20%, according to the American Academy of Sleep Medicine.
The scientists also discovered that caffeine influences the hippocampus, which is an area of the brain responsible for memory and learning. This could be the reason why coffee drinkers in the evening often report feeling confused or disoriented when they wake up the next morning.
So, if you're a fan of your nighttime coffee, it may be time to go decaf. Your brain will thank you come morning!
