A research perspective from Ian Hamilton, an addiction expert at the University of York in England, notes that alcohol disrupts the slow wave portion of sleep, which can leave people feeling tired and slow in the morning. This view is echoed by Daily Mail reports.
The expert points out that the REM sleep phase, marked by higher brain activity, plays a key role in memory, learning, and creativity. It helps the brain rest and recharge. While alcohol can have a sedative effect, consuming it during this phase tends to degrade sleep quality rather than improve it.
As alcohol moves from the stomach and small intestine into the bloodstream, it is metabolized gradually through the night. During the night, digestion and liver activity slow down, which can lead to more frequent awakenings during the rapid eye movement and other sleep stages. This fragmented sleep is associated with morning grogginess and greater daytime fatigue. In addition, alcohol can trigger sweating, which contributes to dehydration. That dehydration often aggravates headaches and worsens the overall health impact of poor sleep.
Historically, there were claims that alcoholic beverages could strengthen memory, yet current understanding shows that regular alcohol intake tends to impair memory formation and recall, particularly when it disrupts sleep patterns. Contemporary research emphasizes that sleep quality is a more reliable predictor of daylong performance than any short-term sedative effect from a nightcap. The takeaway is clear: for restorative sleep, limiting alcohol consumption is advisable, especially in the hours leading up to bedtime.