A large-scale study in Sweden has challenged the conventional wisdom that coffee consumption is inherently detrimental to sleep. Research involving over 25,000 middle-aged adults found that habitual coffee drinking had a minimal and often negligible relationship with self-reported sleep quality and daytime sleepiness.
Published in the journal PLOS One, the cross-sectional study analyzed data from 25,381 participants aged 50 to 64, sourced from the Swedish Cardiopulmonary Bioimage Study. Researchers examined coffee consumption habits against a range of sleep metrics, including duration, quality, and issues like difficulty falling asleep or waking during the night. The authors concluded that the link between regular coffee intake and sleep habits was minimal, describing the overall correlation with perceived sleepiness as “negligible.”
While the study largely decouples coffee from poor sleep, it did reveal some complex associations. Higher coffee intake was paradoxically linked to slightly better self-reported sleep quality, less difficulty falling asleep, and fewer early awakenings. Conversely, it was also associated with a higher frequency of loud snoring. However, the researchers emphasized that these effects were minor in practical terms, with the statistical differences between heavy and light coffee drinkers rarely exceeding a few percentage points.