Myths vs facts: MTHFR and allergy

MTHFR variants (e.g., C677T) are often linked to allergies, but the scientific evidence is weak. While MTHFR affects folate and homocysteine metabolism, a direct causal relationship with allergic conditions like hay fever or eczema is not established. Population studies show small, inconsistent associations. Many commercial tests claim that 'methylation dysfunction' causes allergies – that is a myth. Fact: Allergies are multifactorial (genetics, environment, microbiome). Supplementation with methylfolate or B vitamins has not shown clear benefit against allergies in randomized trials. Beware of exaggerated promises: a single MTHFR SNP does not justify a special diet or therapy. Evidence-based allergy diagnostics (skin prick test, IgE) and possibly immunotherapy are more useful. Genetics can only explain a small fraction of allergy risk.