Having a few glasses of wine or a few beers before bed might seem like an obvious way to relax and help you sleep better, but the reality is that alcohol will affect the quality of your sleep, not to mention create a habitual behaviour that will become increasingly harder to break.
1. Reduced Rem Sleep
The reason people like a drink before bed is because they often fall into a deep sleep very quickly. However, while alcohol increases non-REM sleep, it reduces REM sleep during the first portion of the night.
REM sleep (dream sleep) occurs about 90 minutes after falling asleep, and is thought to be a mentally restorative period of sleep. Alcohol makes you miss out on valuable REM sleep by sending you into a deep sleep too quickly, and then waking you up after just a couple of hours or so.
REM sleep is essential to our mental equilibrium and memory. Tests conducted in sleep labs prove that we become mentally exhausted when REM sleep duration is decreased.
2. Incomplete Sleep Cycles
Alcohol impairs sleep during the second half of the night and can lead to a reduction in overall sleep time. Typically you'll have between 5-7 full cycles of sleep per night, leaving you refreshed and energized. However, if you've been drinking before bed you may have as little as two complete cycles, which will leave you feeling very tired the next day.
3. Waking for the Toilet
Alcohol is a diuretic, which means it it encourages the body to lose extra fluid. This can cause you to be up and down to the toilet several times during the night, depending on how much alcohol you consumed.
Conversely, your toilet runs will leave you dehydrated, prompting your brain to wake you up for a drink of water.
Drinking before bed can make you snore, and very loudly if you're prone to snoring. The alcohol relaxes the muscles in the body, which means the tissue in your throat, mouth and nose can stop air flowing smoothly, causing vibration (snoring)
5. Hunger (Low Blood Sugar)
Alcohol raises blood sugar, and when consumed excessively does so rapidly. What follows is fast production of insulin to bring this level down. Subsequently, your blood sugar drops suddenly, leaving you with low blood sugar, which triggers hunger. This is why people find themselves waking up halfway through the night feeling very hungry.
It is true that one alcoholic drink can relax you into having a good night's sleep. But having two, three or more drinks before bedtime is far more likely to cause you to sleep badly than it is to leave you feeling restored and energized.
Moreover, drinking nightly before bed in a bid to aid sleep will quickly become a habit, much like taking sleeping pills. This dependency is likely to be more psychological than physical in the short term, but regardless will contribute to poor sleep, and further sleeping difficulties for those suffering insomnia.
If you have trouble sleeping, limit your alcohol consumption before bed, and if possible cut it out all together (have a drink on the weekend in the afternoon). If you must have a drink limit it to one drink, two at the maximum, and don't drink alcohol more than twice a week before bed.