The Dietary Effects of Methyl Donors on Asthma and Allergic Sensitization Is Influenced By the MTHFR C677T Polymorphism

Rationale: Some diet can prevent asthma or allergic disease. The aim of this study was to investigate the association between dietary methyl donors (folate, vitamin B2, vitamin B6) and the development of asthma and allergic sensitization in children.

Methods: Children aged 7-13 years in a primary school across Korea were surveyed in 2006 as part of the first CHEER survey and 2,333 children were included in the analysis. Semi-quantitative FFQ were completed and the data were analyzed using the Nutritional Assessment Program CAN-Pro 3.0.

Results: Dietary folate intake was a protective factor for wheezing symptoms in the past 12 months (aOR, 0.69; 95% CI, 0.53-0.91) and asthma diagnosis (aOR, 0.73; 95% CI, 0.53-0.99) and vitamin B6 was also related to reduced risk of allergen sensitization (aOR, 0.74; 95% CI, 0.56-0.99). In addition, high intake of folate, vitamin B2 and vitamin B6 were protective factors for allergen sensitization [(aOR, 0.48; 95% CI, 0.25-0.93), (aOR, 0.50; 95% CI, 0.26-0.95) and (aOR, 0.40; 95% CI, 0.21-0.76), respectively] and atopic wheezing symptoms in the past 12 months [(aOR, 0.17; 95% CI, 0,04-0.80), (aOR, 0.26; 95% CI, 0,07-1.01) and (aOR, 0.26; 95% CI, 0,07-0.99), respectively], especially in CT or TT genotype at nucleotide 677T MTHFR compared to those with low intake and CC at this position.

Conclusions: These results indicate that dietary methyl donors decrease the risk of asthma and allergic sensitization, which may be influenced by the MTHFR polymorphism.

Funding sources: This study was funded by the Ministry of Environment, Korea