How a Glass (or Two) of Wine Before Bed Impacts your Sleep

By Kyle Jaeger

I love wine. No, like, I really love wine—especially around the time that I’m decompressing at the end of a long day. And, sometimes, I pour a glass just before bed to ensure a swift and sound sleep. There’s a term for that, of course: a nightcap.

But how does drinking wine right before bed really affect your sleep? I (reluctantly) asked an expert, Dr. Timothy Roehrs, director of research at the Sleep Disorders and Research Center of Detroit’s Henry Ford Hospital.

Roehrs, who recently studied the impact of alcohol consumption before bed among individuals who suffer from sleep disorders in a forthcoming paper to be published in the journal Sleep, gave me a lot of complicated numbers to mull over. He hasn’t specifically investigated the impact of vino consumption on sleep, but he was kind enough to contextualize his research on alcohol and sleep to deliver answers to questions I’ve personally been curious about—and maybe you’ve been, too.

LET’S DIG IN

First, a warning. Roehrs was quick to point out that using any type of alcohol as an explicit means of falling asleep can represent a “dangerous pattern.” You build a tolerance to booze, like any drug, and so if you consistently use wine as a nightcap, you’re going to find yourself needing higher and higher doses to achieve the desired effect: sleep. If you’ve found that a glass of wine before bed helps you sleep—which, of course, given its sedating effects, it probably does—you may eventually run the risk of needing an additional pour (and then another) to get you to that drowsy, sedated state. It’s no secret that too much booze is bad for your liver and other vital organs, so keep intent in mind.

“I would advise against [drinking wine before bed] if, in fact, the purpose is to facilitate sleep,” Roehrs told me. “If it's being consumed in a social setting, I don't see a problem—given those doses and timeframes that we have discussed.”

(I’ll get into those doses and timeframes shortly. Standby.)

OK, NOW FOR SOME PRACTICAL ADVICE.

Here’s generally what happens when you drink wine (or any alcohol, for that matter) before bed. Keep in mind that it takes several hours—for example, 5 hours if you’ve raised your blood alcohol concentration (BAC) to .05 percent—to fully metabolize the alcohol, so it’s likely that your sleep will be disrupted if you’re drinking wine just before bed. There are multiple stages of sleep, however, so allow me explain how that plays out.

Let’s say you drink a glass of wine just before bed, OK? Depending on your definition of a “glass” of wine (i.e. the concentration of alcohol you consume), your body is going to need some time to process that in order to ensure undisrupted sleep. Let me just offer this hypothetical scenario: You drink a standard glass of wine (14 grams of pure alcohol) just before bed. Well, just because you fell asleep, that doesn’t mean that your body stopped metabolizing the alcohol. For the purposes of this article, think about sleep stages in two stages—assuming you’re getting the recommended eight hours of sleep per night.

“[Drinking wine before bed] will actually increase deep, slow-wave sleep and suppress REM sleep during the first four hours of the night,” Roehrs said. “And then, during the second four hours of the night, there's increased wakefulness and disruption of sleep.”

Nobody likes to be jerked awake in the midst of a deep sleep, so it should go without saying that increased wakefulness during the night is an agreeably frustrating, and avoidable, issue.

While the jury is out on the exact functions of REM (rapid eye movement) sleep, there are some hypotheses about why it’s important. It may, according to the existing, scientific literature, play a role in memory function and mood. So let’s be clear, having REM sleep suppressed during the first half of your sleep cycle probably isn’t great for you. But no matter what you put in your body to suppress REM sleep, it eventually rebounds—and when it comes to moderate alcohol consumption, it typically rebounds during the second sleep stage (i.e. the final four hours).

FINALLY, THE ANSWER YOU’VE ALL BEEN WAITING FOR.

You want a healthy, undisrupted sleep cycle. So when do you stop drinking?

“We typically, usually, caution people and say two-to-three hours before for you go to bed,” Roehrs said. “Now, if you've been drinking heavily, it'll be more than that.”

OK, THERE IT IS:

Drinking wine before bed isn’t the worst thing in the world. In some cases—for instance, if you suffer from sleep disorders like insomnia—it can actually be helpful by enabling you to enter into deep sleep faster. But the impact of wine consumption on REM sleep is something to keep in mind, so timing is critical. Take the doctor’s advice and avoid using wine as an explicit means of falling asleep. And if you are drinking before bed, give yourself a few hours in advance just to make sure your sleep cycle is healthy.