Gardiner · Sleep medicine reviews 2025 · systematic review and meta-analysis · n=27 studies

The effect of alcohol on subsequent sleep in healthy adults: A systematic review and meta-analysis.

Cited 49 times in the scientific literature.

Level 1 - systematic review of randomized trials

Systematic review and meta-analysis of 27 studies

PubMed 39631226 · doi:10.1016/j.smrv.2024.102030 · record verified 2026-08-29

What was done

A systematic review and meta-analysis of 27 studies was conducted to evaluate the effects of pre-bedtime alcohol dose and timing on night-time sleep characteristics and sleep architecture in healthy adults.

What was found

Alcohol caused a delay in rapid eye movement (REM) sleep onset and reduced REM sleep duration in a dose-dependent manner. Disruptions to REM sleep appeared at low doses (≤0.50 g/kg, or approximately two standard drinks) and progressively worsened with higher doses. Decreased sleep onset latency and decreased latency to stage 3 (N3) deep sleep were observed only at high alcohol doses (≥0.85 g/kg, or approximately five standard drinks). The abstract reported no specific numerical effect sizes or confidence intervals, and noted that effects on total sleep time, sleep efficiency, and wake after sleep onset could not be determined due to large uncertainty.

Why it matters

This review clarifies that even low doses of alcohol impair REM sleep architecture, showing that the perceived sleep-promoting effect of alcohol (faster sleep onset) only occurs at high doses alongside worsened sleep disruption.

Limits

The abstract did not report the total participant sample size, precise effect sizes, or confidence intervals. The effects of alcohol on total sleep duration, sleep efficiency, and wake after sleep onset remained uncertain, and individual metabolic factors or sex-specific differences were not determined.

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