What to watch with Homocystein and Langlebigkeit?

Homocysteine is a sulfur-containing amino acid derived from methionine metabolism. Elevated levels are considered an independent risk factor for cardiovascular disease, stroke, and cognitive decline – all factors that impact longevity. However, the evidence is nuanced: observational studies show clear associations, but randomized controlled trials (RCTs) with B vitamins (folate, B6, B12) to lower homocysteine have not demonstrated significant lifespan extension or reduction in cardiovascular events. This suggests homocysteine is more a marker than a causal driver. Genetic variants like MTHFR C677T influence homocysteine levels but have very small effects on life expectancy in large GWAS. Consumer DNA tests that analyze homocysteine or MTHFR often overstate clinical relevance. Practically: an elevated homocysteine level should be medically evaluated, especially for vitamin B12 and folate deficiency. Supplementation without deficiency is not evidence-based and may carry risks (e.g., masking B12 deficiency with folate). For longevity, established factors like diet, exercise, and not smoking are far more important. Evidence: human-moderate (observational studies, mixed RCTs).