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Caffeine can change the brain’s gray matter

The most commonly used psychoactive substance in the world is caffeine. It is mainly consumed in the form of coffee, tea, cola, energy drink or soda. According to a new study conducted at the University of Basel, when taken regularly, caffeine can induce short-term changes in the gray matter of the brain.

Caffeine not only boosts energy levels but also improves mental performance. However, when consumed in excess, it can cause adverse symptoms such as jitteriness in some people. Therefore, consuming caffeine in the evening can disrupt our sleep. And according to a previous study, lack of sleep can affect the brain’s gray matter, which is the cluster of nerve cells that together with the white matter make up the central nervous system of humans.

The gray matter is made up of many nerve cells that, because they are very numerous, take on a dark color. This is the origin of the common name of these clusters, namely gray cells.

The results of the study obtained by scientists from the University of Basel turned out to be quite surprising. Caffeine did not cause any deterioration of sleep quality in people participating in the experiment. However, changes were observed in the gray matter of their brain.

The study was conducted on 20 healthy, young people who regularly consumed coffee with caffeine. However, for the duration of the experiment, these individuals were not allowed to take caffeine in any form. Their task was to take special pills for a period of 20 days. The subjects took caffeine tablets for the first 10 days and tablets without caffeine, known as placebos, for the next 10 days. At the end of each 10-day period, the researchers measured the study participants’ gray matter volume using brain scans. They also monitored the participants’ sleep quality by recording brain activity with a non-invasive EEG method.

The results showed that regardless of whether the participants in the experiment took caffeine pills or a placebo, the depth of their sleep was the same. However, a significant difference was observed in the gray matter volume of the participants’ brains. After 10 days of taking the tablets without caffeine (placebo), the volume of gray matter was larger than after 10 days of taking the increased amount of caffeine. A particularly large difference was noticed in the right temporal lobe of the participants’ brains, the part of the brain responsible for memory. The researchers concluded that daily caffeine consumption clearly affects the human mind, but not necessarily negatively.

Although studies indicate that caffeine reduces gray matter volume, the changes in brain morphology appear to be temporary as the brain regenerates. There is still a need for studies comparing people who regularly consume coffee with those who typically consume little or no caffeine.

These findings are described in the article entitled „Daily Caffeine Intake Induces Concentration-Dependent Medial Temporal Plasticity in Humans: A Multimodal Double-Blind Randomized Controlled Trial” published in the journal Cerebral Cortex  21.02.2021(Authors: Lin Y., Weibel J., Landolt H.P., Santini F., Meyer M., Brunmair J., Meier-Menches S.M., Gerner Ch., Borgwardt S., Cajochen Ch., Reichert C.) DOI:
Translation was done with the assistance of DeepL translator.