Wine and (my) Sleep

Published: 2/4/2022

Based on the results of a Twitter poll, I've been drinking a glass of wine an hour or two before bed every night. I've heard from 'big sleep' expert Matthew Walker [1] that alcohol is bad for your sleep. Even just one glass of wine. I figured I'd look into my personal sleep data and see what I could learn.

A note on studies before looking into my data. I could not find many studies which indicate one drink is harmful for sleep. I found many that say three drinks or more is bad. Here's one observational study which finds a very small effect size for one drink negatively effecting the first three hours of sleep. I'd be interested in seeing more definitive studies.

Experimental Limitations

Just to get ahead of the obvious critiques, keep in mind:


You can see my data here. Note I cut it off the day we took our daughter home from the NICU because things got a little wonky then. And I started in October sort of arbitrarily, I've been wearing the fitbit since August. I also track my daily habits with daylio and deleted a couple days from after December 24th when I started my new habit when for whatever reason I didn't have a drink. The day by day is too noisy to look at and see anything but the 7 day average shows a very noticeable increase in REM around December 24th when I started drinking wine.

The data showed an increase in my REM sleep of 2.9% which a t-test indicates is significant at the 0.0002 level. My deep sleep was virtually unchanged with a truncated average of 15.5% for both time periods. My time awake decreased by 1% but only at the 0.08 significance level.

Note I didn't use Fitbit's sleep score because it's bullshit. They're in the pocket of 'big sleep'. They always give you higher scores for sleeping longer but I'd rather have 6.5 hours with no major wakes and 25% rem and 16% deep than 9 hours with multiple major wakes and 18% and 12% for instance. But Fitbit prefers the later.


These results are definitely good enough for me to keep up my habit. It's harder to quantify but I also feel I fall asleep faster and wake up feeling subjectively better rested now. I was surprised by the increase in REM because most studies I've seen say that's among the more negatively impacted parts of sleep. I'd encourage readers to try it out for themselves. Though definitely monitor how you're feeling for yourself and stop if you're getting different results than me.


[1] And notorious hack. This is now an anti-science blog.