Folic acid is known to be associated with inflammatory diseases, but the relationship between folic acid and allergic diseases is unclear.
Folic acid (folate). Image source: Wikipedia, public domain.
Data were obtained from the 2005-2006 National Health and Nutrition Examination Survey in which serum folate and total IgE levels were measured in 8083 subjects 2 years of age and older.
A high total IgE level was defined as greater than 100 kU/L. Allergen-specific IgE levels were measured for a panel of 5 common aeroallergens. Atopy was defined as at least 1 positive allergen-specific IgE level.
Serum folate levels were inversely associated with total IgE levels. The odds of a high total IgE level, atopy, and wheeze decreased across quintiles of serum folate levels, indicating a dose-response relationship between serum folate levels and these outcomes.
The authors concluded that serum folate levels are inversely associated with high total IgE levels, atopy, and wheeze.
Higher serum folate levels are associated with a lower risk of atopy and wheeze. Matsui EC, Matsui W. J Allergy Clin Immunol. 2009 Apr 29.