During the holidays, my wife and I had a terrible night of sleep. We went to bed at 10 p.m. and fell asleep quickly. However, we both were unable to return to sleep after getting up from the bathroom at 2:30 a.m. This is unusual for us to both awake in the middle of the night at the same time!
I tried to think of a possible cause. The prior period of wakefulness determines how you sleep. I tried to think of what was unusual about our day. We exercised in the afternoon and walked outdoors during the daylight. Both of these activities promote a good night’s sleep.
Then, I remembered having a 100mL glass of wine at 5 p.m. (I know it was a 100 mL because I measured it out - this is the equivalent to a standard drink in Australia!) We usually buy a litre of wine for the holidays and enjoy it slowly. This is the only time we have alcohol.
I was unsure that if this was the cause. The alcohol technically should have been cleared from my system in five hours. So, unable to sleep at 2:40 a.m., I was looking for a scientific study on PubMed to confirm this hypothesis that alcohol could cause sleeplessness hours later. I found this article. Twenty-five years earlier, a researcher invited 10 research participants (my guess is his friends!) for a simulated “Happy Hour”.
Each participant drank the equivalent of 0.55 g/kg of alcohol. This is a meaningless unit for most people. A person weighing 80 kg - approximately 175 lbs, would have consumed 44 grams of alcohol. So, you are thinking, “What is 44 grams of alcohol?” A 5% beer that was 341 ml or 12 oz would contain 13.6 grams. This would equate to three bottles of beer. (Definitely, a Happy Hour!)
Six hours later the participants had a breathalyzer to determine that there was no alcohol in their system. While they slept, they were hooked up to machines to analyze their brain activity. The researchers found more wakefulness in the second half of sleep. This is the stage of sleep where REM or dreams occur. Thus, the participants had a light sleep, and their REM sleep was compromised.
Each sleep cycle lasts 90 minutes. The recommended amount of sleep for adults in 7 to 9 hours which works out to be 5 to 6 sleep cycles. My wife and I woke up 4.5 hours later. Three sleep cycles had passed. This would put us in the second half of our sleep. This study explains why we did not sleep well after having a glass of wine. Because we do not have the liver enzymes to metabolize alcohol efficiently (because we rarely drink), the alcohol had more of an effect.
Associations are interesting for me. However, I find that reasons and mechanisms are more enchanting. Please stay tuned to for the second part of this blog as I explore the chemistry behind a terrible night’s sleep! Thanks for reading!! #lifestylemedicine #seniors #insomnialife
