Myths vs facts: Homocystein and Allergie

Homocysteine is primarily known as a cardiovascular risk marker, but its role in allergies is often misunderstood. Myth: Elevated homocysteine directly causes allergies, or MTHFR variants predict allergic reactions. Fact: Observational studies suggest a modest association between higher homocysteine levels and allergic conditions such as asthma, atopic dermatitis, and allergic rhinitis. The mechanism may involve oxidative stress, inflammation, and impaired methylation affecting immune regulation. However, evidence is moderate and not causal; lowering homocysteine with B vitamins has not been proven to prevent or treat allergies. DNA tests for MTHFR C677T indicate a genetic tendency toward elevated homocysteine but do not diagnose allergies. For allergy evaluation, specific IgE testing or skin prick tests remain the gold standard. Homocysteine measurement can be useful in a clinical context, especially when combined with B vitamin status assessment. Caveat: Direct-to-consumer tests may overstate the link; always consult an allergist or physician for proper diagnosis and management.