correlational

Taking 3 grams of glycine before bed might help people who have trouble sleeping feel like they slept better, according to their own reports.

Scientific Claim

Ingestion of 3 grams of glycine before bedtime is associated with improved subjective sleep quality in individuals with chronic sleep dissatisfaction, as measured by the St. Mary's Hospital Sleep Questionnaire.

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 uses 'improved' which implies causation, but the study design (individual cohort study with unclear randomization and blinding) only supports associative language.

Evidence from Studies

No evidence studies found yet.