Scientists have discovered the surprising effect of constant caffeine consumption on sleep

Scientists from Switzerland and the UK have found that regular consumption of four or more caffeinated drinks a day reduces sleep duration, while increasing its depth. This was reported by the authors of the study, published in The results were published in the Journal of Psychopharmacology.

The researchers conducted a large-scale analysis to examine the effects of chronic caffeine consumption on sleep quality. Both objective polysomnography data and subjective sleep assessment questionnaires were used for the assessment.

The results showed that participants who consumed four or more caffeinated drinks a day slept an average of 11-13 minutes less than those who limited themselves to three drinks. At the same time, the depth of sleep according to electroencephalography (EEG) increased, which indicates a possible compensation of the body and the preservation of the basic mechanisms of sleep regulation.

The authors of the study noted that participants with high caffeine intake experienced a reduction in total sleep duration, while an increase in the depth of NREM sleep, in their opinion, could indicate an adaptation of the body. At the same time, the subjective assessment of sleep quality and activity preferences during the day did not differ between the groups.

For the analysis, the researchers used Mendelian randomization (MR) methods, including MR-Egger, inverse variance weighting, and median weighting. These approaches have made it possible to identify causal relationships between caffeine consumption habits and changes in sleep physiology, minimizing the impact of concomitant factors.

Experts emphasized that even a slight reduction in sleep with regular caffeine consumption can have health consequences, given the importance of a good night's rest for cognitive, immune, and cardiovascular functions.

On September 30, Maria Tolstova, a therapist at the SM Clinic, called less than 400 mg of caffeine per day an acceptable norm for health. According to the expert, excessive coffee consumption can worsen existing diseases of the cardiovascular or digestive system, lead to palpitations, and increase blood pressure.

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