correlational

Taking 3 grams of glycine before bed might help people spend more time actually sleeping compared to time spent in bed.

Scientific Claim

Glycine ingestion at 3 grams before bedtime is associated with increased sleep efficacy (sleep time/in-bed time) in individuals with chronic sleep dissatisfaction, as measured by polysomnography.

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.