NICOTINE AND LIQUOR ARE WORSE THAN CAFFEINE FOR SLEEP

If you’ve ever struggled to fall or stay asleep, you’ve heard all the standard sleep-hygiene advice: Stick to the same sleep and wake times, establish a bedtime routine, create a relaxing sleep environment, and avoid caffeine in the afternoon.

Turns out that last bit might not be as much of a problem as other evening habits. In a study of 785 African American adults with no history of sleep issues, 45 percent reported drinking coffee, tea, or soda within four hours of bedtime at least once in the course of a week. (African Americans have been underrepresented in sleep studies but are more likely to experience sleep problems and associated health issues.) Data from wristwatch sensors showed that the caffeine had no significant effect on how well or how long they slept.

However, drinking alcohol or using nicotine before bed reduced participants’ sleep efficiency, meaning that the percentage of time they spent in bed actually sleeping was lower. With nicotine use, people also woke up more often in the middle of the night, perhaps because they were experiencing withdrawal symptoms.

Subjects who reported symptoms of insomnia during the study were more likely to have used nicotine before bed, which made their insomnia worse, robbing them of more than 40 minutes of sleep. Nicotine use before bed was also associated with symptoms of depression and anxiety, while alcohol and caffeine use were linked to chronic stress.