correlational
Taking 3 grams of glycine before bed might help people who have trouble sleeping feel like they slept better
Scientific Claim
Glycine ingestion (3 g) before bedtime is associated with improved subjective sleep quality in individuals with poor sleep, 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 design (individual cohort study) cannot establish causation. Only association can be claimed.
Evidence from Studies
No evidence studies found yet.