Many people use alcohol as a sleep-promoting sedative and find that consuming a moderate amount of beverage alcohol before bedtime helps them to fall asleep. Alcohol does have a sedating effect, and it is likely to reduce sleep latency in healthy adults (i.e, the time required to fall asleep.) However, studies have found that alcohol consumed near bedtime tends to disrupt the second half of the sleep period – causing awakenings followed by difficulty returning to sleep. The sleep disruption caused by alcohol consumption may lead to daytime fatigue and sleepiness the following day.
Consumption of alcohol as much as six hours prior to bedtime can increase wakefulness during the second half of sleep. A recent study published in Alcoholism: Clinical & Experimental Research also found that the sleep disruption caused by alcohol consumption has a greater effect on women.
In addition to sleep disruption, moderate to high doses of alcohol consumed late in the day may pose a risk for developing obstructive sleep apnea. Specifically, it may cause a narrowing of the air passage – provoking episodes of sleep apnea in those that do not normally suffer from the condition, or worsening symptoms in those who already have a sleep apnea diagnosis.
The occasional glass of wine or drink of whisky near bedtime may not cause any long-term negative impact on sleep. However, it is important to keep in mind the potential disruptive effects of alcohol, and remember the more alcohol consumed increases the risk of a restless, sleep-interrupted night. A wiser choice for a routine bedtime beverage would be a cup warm milk or caffeine-free herbal tea.