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

Glycine ingestion (3 g) 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 definitive language ('improved') but is an observational cohort study without confirmed randomization or control group, so causation cannot be established. The verb should reflect association rather than improvement.

More Accurate Statement

Glycine ingestion (3 g) before bedtime is associated with self-reported improvements in sleep quality among individuals with chronic sleep dissatisfaction, as measured by the St. Mary's Hospital Sleep Questionnaire

Evidence from Studies

No evidence studies found yet.