What role does LCT play in Müdigkeit?

The LCT gene encodes lactase, the enzyme that breaks down lactose in dairy. Genetic variants (e.g., rs4988235) determine lactase persistence or non-persistence (lactose intolerance). There is no direct, well-established link between LCT variants and fatigue in the scientific literature. However, in individuals with lactose intolerance, consuming dairy can cause gastrointestinal symptoms such as bloating, cramping, or diarrhea. These symptoms may indirectly affect sleep quality or nutrient absorption, potentially contributing to feelings of tiredness. This connection is mechanistic and speculative; robust human studies specifically linking LCT genotype to fatigue are lacking. Fatigue is multifactorial – common causes include iron deficiency, thyroid disorders, sleep apnea, stress, and poor diet. A consumer DNA test for LCT cannot diagnose or explain fatigue. If you experience persistent tiredness, consult a healthcare professional for a comprehensive evaluation. The provided context does not include direct evidence on LCT and fatigue.