The concept and practice of a nightcap—having a small alcoholic drink before bed in order to get a good night's sleep—has been around since the 1700s. But recently, its validity as a sleep aid has been questioned.
A new review of published studies, involving the sleeping habits of over 500 people who had a nightcap before a snooze in the sleep lab, reveals that a quick drink before bed won’t actually help you get a better night’s sleep. Those who drank, no matter the amount, did in fact fall asleep faster and spent more time in a deep sleep for the first half of the night. However, as the night progressed, they woke up more frequently, experiencing increased sleep disruption—presumably as the alcohol’s effects wore off.
The alcohol also led to an overall drop in rapid eye movement (REM) sleep throughout the night. REM sleep is a natural stage in the sleep cycle in which dreams occur, and is thought to be important to the organization of memories and retention of learning.
So if you like dreaming, memories and learning, not to mention sleeping through the night, that nightcap isn’t the way to go. It might help you fall asleep faster, but it won’t keep you asleep, so you won’t wake up feeling as refreshed and well-rested as you’d like.