Regular consumption of caffeine affects the structure of the brain

Coffee, cola or energy drink: caffeine is the most consumed psychoactive substance in the world. Researchers at Basel University have now shown in a study that regular caffeine intake can alter brain gray matter. However, the effect appears to be temporary.

Without a doubt, caffeine helps most of us to feel more alert. However, it can interrupt our sleep if consumed at night. Sleep deprivation can, in turn, affect the gray matter of the brain, as previous studies have shown. So, can regular caffeine consumption affect the structure of the brain due to lack of sleep? A research team led by Dr. Carolin Reichert and Professor Christian Cajochen at the University of Basel and UPK (Basel University Psychiatric Hospital) investigated this issue in one study.

The result was surprising: the caffeine consumed as part of the study did not result in poor sleep. However, the researchers observed changes in gray matter, as they report in the journal. Cerebral cortex. The gray matter refers to the parts of the central nervous system made up mainly of the nerve cell’s cellular bodies, while the white matter mainly comprises the neural pathways, the long extensions of the nerve cells.

A group of 20 healthy young people participated in the study, all of them consuming coffee regularly, daily. They were given pills to take more than two 10-day periods, and were told not to consume any other caffeine during that period. During a study period, they were given caffeinated pills; in the other, pills without active ingredient (placebo). At the end of each 10-day period, the researchers examined the individuals’ gray matter volume through brain scans. They also investigated the sleep quality of participants in the sleep laboratory, recording the brain’s electrical activity (EEG).

Sleep unaffected, but not gray matter

Comparing the data revealed that the participants’ sleep depth was the same, regardless of whether they took the caffeine or the placebo capsules. But they saw a significant difference in gray matter, depending on whether the subject had received caffeine or placebo. After 10 days of placebo – that is, ‘caffeine abstinence’ – the volume of gray matter was greater than after the same period of time with caffeine capsules.

The difference was particularly noticeable in the right medial temporal lobe, including the hippocampus, a region of the brain that is essential for memory consolidation. “Our results do not necessarily mean that caffeine consumption has a negative impact on the brain,” emphasizes Reichert. “But daily caffeine consumption evidently affects our cognitive hardware, which in itself should lead to further studies.” She adds that in the past, the health effects of caffeine have been investigated mainly in patients, but there is also a need for research in healthy individuals.

Although caffeine appears to reduce the volume of gray matter, after only 10 days of coffee withdrawal, it has significantly regenerated in the test subjects. “Changes in brain morphology seem temporary, but so far there has been a lack of systematic comparisons between coffee drinkers and those who normally consume little or no caffeine,” says Reichert.