What role does MTHFR play in skin aging?

MTHFR (methylenetetrahydrofolate reductase) is a key enzyme in folate and homocysteine metabolism. Variants such as C677T reduce enzyme activity, potentially raising homocysteine levels. Elevated homocysteine is linked to oxidative stress, reduced collagen synthesis, and accelerated skin aging via elastin degradation and inflammation. However, the evidence is largely mechanistic and observational; direct clinical proof that MTHFR variants cause skin aging is weak. Lifestyle factors (folate intake, B vitamins) modulate the effect. A direct-to-consumer DNA test (e.g., MyBody-X) can detect these variants, but predictive value for skin aging is low without accompanying biomarkers like plasma homocysteine. Supplementation based solely on genotype is not supported by robust trials. In summary, MTHFR plays a plausible but unproven role in skin aging; evidence is mechanistic/mixed.