A large population study published in PLOS One, covering 25,381 adults aged 50 to 64 from the Swedish Cardiopulmonary Bioimage Study (SCAPIS), found that habitual coffee drinking has a surprisingly weak link to sleep quality or daytime sleepiness — contrary to popular belief.
Researchers found that higher coffee intake was even associated with slightly better self-reported sleep quality, less difficulty falling asleep, and fewer early awakenings, though also with more frequent loud snoring. One possible explanation relates to participants' age: prolonged caffeine exposure may lead to a "normalization" of the brain's adenosine system, which governs feelings of sleepiness.
The findings suggest that, at least among middle-aged and older adults who drink coffee regularly, it may not be the sleep villain it's often made out to be.
Source: Daily Coffee News