How are MTHFR and allergy related?

The relationship between MTHFR and allergies remains scientifically inconclusive. MTHFR encodes a key enzyme in folate metabolism, which influences methylation and thereby histamine breakdown. Some studies suggest that certain MTHFR variants (e.g., C677T) may be associated with increased risk of allergic conditions like asthma or hay fever, possibly through epigenetic changes or altered homocysteine levels. However, effect sizes are small, the evidence is heterogeneous, and findings are often not replicated. The provided knowledge context contains no direct information on MTHFR and allergies. Therefore, no evidence-based conclusion can be drawn from this data alone. Consumers should understand that a genetic test for MTHFR does not diagnose or predict allergies. Comprehensive allergy assessment, including environmental, dietary, and lifestyle factors, is essential. Evidence: unclear – mechanistic plausibility exists, but strong clinical evidence is lacking.