Sleep interrupted: What's keeping us up at night?

One of the largest longitudinal studies to date examined evening consumption of alcohol, caffeine and nicotine among an African-American cohort and objectively measured sleep outcomes in their natural environments instead of laboratory or observatory settings. The study involved 785 participants and totaled 5,164 days of concurrent actigraphy and daily sleep diaries that recorded how much alcohol, caffeine or nicotine they consumed within four hours of bedtime. Results may be good news for coffe...