If you’re concerned about getting a good night’s sleep, you’re better off having an espresso than a night cap.
That’s according to a surprising new study that found drinking alcohol within four hours of sleep is far more likely to disrupt your sleep than caffeine.
Nicotine – whether from smoking cigarettes or vaping – was even more strongly associated with insomnia, particularly if vaped or smoked in the evening.
As for coffee, the researchers at Florida Atlantic University, Harvard, Emory, and Mississippi Medical Center found no significant link to sleeplessness.
Even after controlling for other factors that could influence their sleep – such as their age, gender, whether they are obese, if they have work or school the next day, if they are depressed, anxious, stressed – caffeine really had little impact on sleep
The study, which followed 785 African Americans for 14 years, is particularly enlightening for African Americans, who disproportionately suffer from insomnia, sleep apnea and other sleep-related disorders compared to others.
The research is one of the largest longitudinal studies on how alcohol, caffeine and smoking at night affects sleep.
None of the people in the study suffered from clinical sleep disorders.
Each person was given a wrist-band sensor to monitor their sleep, as well as a journal to jot down how they slept, how they felt, and what they ate, smoked or drank nightly.
Self reports are subject to error, but the researchers were confident in the consistency of their findings, published today in the journal Sleep.
Even after controlling for other factors that could influence their sleep – such as their age, gender, whether they are obese, if they have work or school the next day, if they are depressed, anxious, stressed – caffeine really had little impact on sleep.
Sleepless nights were routinely reported after drinking – often after happy hour drinks, but most commonly if the person drank closer to their bedtime.
Nothing compared to nicotine, though.
Those who vaped or smoked tended to sleep, on average, 43 minutes less than their non-smoking counterparts.