BASEL, Switzerland — There are those who believe drinking caffeine too late will keep them awake all night. Others, however, feel their brain just can’t function unless they have a hot cup of coffee in them. A new study may be unraveling both of those beliefs. Researchers from the University of Basel say regular caffeine consumption does not disrupt sleep quality, but it can alter the structure of the brain connected to memory.
Whether it’s coffee, cola, or energy drinks, study authors say caffeine is the world’s most consumed psychoactive substance. Their findings reveal that even consuming it for a short period of time can change the volume of gray matter in the brain.
The good and bad of caffeine
Being a stimulant, caffeine helps most people who drink it to feel more alert and awake. However, consuming too much before bed has been linked to symptoms of insomnia. No matter how it happens, lack of sleep is never good for the brain or the body.
Previous studies reveal that sleep deprivation can impact the amount of gray matter in the brain as well. Gray matter is part of the central nervous system, consisting mostly of the cell bodies of nerve cells. The brain’s white matter, on the other hand, mainly makes up the mind’s neural pathways. These are the long extensions of the nerve cells.
So does caffeine really play a role in causing the damage done by sleep deprivation? Researchers led by Dr. Carolin Reichert and Professor Christian Cajochen examined 20 healthy individuals who all drink coffee on a regular basis.
Is caffeine’s impact on sleep just a myth?
The group of young adults replaced their daily coffee habit with tablets during two 10-day trials. One of the experiments involved actual caffeine tablets, but the other gave participants placebos with no caffeine in them at all.
At the end of each 10-day trial, researchers analyzed the volume of gray matter in each person using brain scans. Each participant also had their sleep quality measured in a sleep laboratory which recorded their brain’s electrical activity at night.
The surprising results reveal caffeine use does not result in poorer sleep. However, researchers find there are significant changes in the volume of gray matter just in the 10 days with or without caffeine in a person’s system.
After 10 days of no caffeine, participants had a much higher volume of gray matter in the brain than they did while consuming caffeine. The differences are especially noticeable in the brain’s right medial temporal lobe. This area includes the hippocampus, which is essential for memory consolidation.
“Our results do not necessarily mean that caffeine consumption has a negative impact on the brain,” Dr. Reichert says in a university release. “But daily caffeine consumption evidently affects our cognitive hardware, which in itself should give rise to further studies.”
Brain changes from caffeine are only temporary
While caffeine may shrink the amount of gray matter in the brain, the study finds these changes don’t last for long if a person stops consuming the stimulant. Researchers say gray matter regenerated in the subjects during their 10 days on the placebo pills.
Until now, the health impact of caffeine has mostly been studied in people with medical issues. Study authors say there is less information available on caffeine’s impact on healthy bodies.
“The changes in brain morphology seem to be temporary, but systematic comparisons between coffee drinkers and those who usually consume little or no caffeine have so far been lacking,” Reichert concludes.
The study appears in the journal Cerebral Cortex.