Evidence check: ADH1B in the context of fatigue

ADH1B encodes alcohol dehydrogenase, which metabolizes ethanol to acetaldehyde. Certain variants (e.g., rs1229984) accelerate this step, leading to higher acetaldehyde levels – known for flushing, nausea, and headache after alcohol intake. A direct link to fatigue independent of alcohol is not scientifically established. Fatigue is multifactorial (sleep, diet, stress, hormones, inflammation). The provided context contains no specific studies on ADH1B and fatigue. Therefore, evidence is rated as 'unclear'. Even in drinkers, the effect on fatigue is indirect and highly individual. No specific recommendations outside a medical consultation. Caveat: consumer DNA tests often overstate single-gene effects.