Myths vs facts: Homocystein and Schlaf

The claim that homocysteine directly affects sleep is weakly supported by science. Homocysteine is a sulfur-containing amino acid; elevated levels (hyperhomocysteinemia) are linked to cardiovascular risk and neurodegeneration. Some small studies suggest an association between high homocysteine and sleep disorders like insomnia or sleep apnea, but effects are small and causality unclear. Elevations are usually due to B-vitamin deficiencies (B6, B12, folate) or genetic variants (MTHFR). Consumer DNA tests that claim a direct impact on sleep overstate the evidence. Sleep quality is determined by many factors – light, stress, hormones, circadian rhythm – and homocysteine plays at most a minor role. Evidence: unclear. Caveat: No clinical relevance for sleep optimization can be derived from current evidence.