Evidence check: LCT in the context of Schlaf

The link between LCT (lactase persistence) and sleep is poorly supported by evidence. LCT variants determine adult lactose digestion. An indirect effect on sleep is plausible if lactose intolerance causes bloating, abdominal pain, or nighttime discomfort, potentially impairing sleep quality. However, no direct studies connect LCT genotypes to sleep parameters like latency, duration, or architecture. Evidence is limited to mechanistic reasoning and general knowledge about digestive distress. Consumer DNA tests for LCT reliably indicate lactose tolerance, but extrapolating to sleep recommendations is speculative. For sleep issues, more evidence-based factors include stress, sleep hygiene, or MTNR1B variants (melatonin receptor). Overall, evidence for LCT and sleep is rated 'unclear'.