correlational

Taking 3 grams of glycine before bed might help people who have trouble sleeping feel like they slept better.

Scientific Claim

Glycine ingestion at a dose of 3 grams before bedtime is associated with improved subjective sleep quality in individuals with chronic sleep dissatisfaction, as measured by self-reported sleep assessments.

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 abstract uses 'improved' which implies causation, but the study's RCT classification has unclear randomization and blinding details per GRADE analysis, so definitive causal language is inappropriate. Association is the correct verb strength.

Evidence from Studies

No evidence studies found yet.