correlational

Taking 3 grams of glycine before bed might help people fall asleep faster and reach deep sleep quicker, based on sleep monitoring equipment.

Scientific Claim

Ingestion of 3 grams of glycine before bedtime is associated with reduced sleep onset latency and slow wave sleep latency in polysomnographic measurements among individuals with chronic sleep dissatisfaction.

Original Statement

Glycine improved subjective sleep quality and sleep efficacy (sleep time/in-bed time), and shortened PSG latency both to sleep onset and to slow wave sleep without changes in the sleep architecture.

Evidence Quality Assessment

Claim Status

overstated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The study design (cohort study) cannot establish causation, but the abstract uses 'shortened' which implies causation. The correct verb strength should be 'associated with reduced' or 'linked to shorter'.

Evidence from Studies

No evidence studies found yet.