New Research Suggests Heavy Caffeine Intake May Deepen Non-REM Sleep Despite Reducing Total Sleep Time
Recently published research in the Journal of Psychopharmacology indicates that heavy caffeine consumption, defined as four or more caffeinated drinks daily, is associated with a shorter total sleep duration. However, the study also found a surprising correlation: individuals with high caffeine intake experienced a deeper non-rapid-eye-movement (NREM) sleep depth compared to those who consumed less caffeine. NREM sleep depth refers to how profoundly a person sleeps during the transition from light to deep sleep. The study analyzed data from over 485,000 participants in the UK Biobank and 1,700 individuals from the HypnoLaus cohort, a Swiss study that includes data on genetics, caffeine intake, and sleep. Despite the finding of increased NREM depth, sleep medicine physicians, including Dr. Beth Malow of Vanderbilt Health and Dr. W. Christopher Winter of Charlottesville Neurology and Sleep Medicine, caution against interpreting these results as a benefit of caffeine for sleep. They suggest that the increased...