Recent data have shown that the prevalence of asthma and allergic disease continuously increase. Some diet can prevent asthma or allergic disease by epigenetic change, including DNA methylation. 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.
Children aged 7-13 years in a Korean elementary school were surveyed in 2006 as part of the first Children's Health and Environmental Research (CHEER) survey and 2,333 children were included in this study. Korean version of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and food frequency questionnaire (FFQ) were done by their parents. The skin prick test was performed using 18 common allergens in Korea. Genotyping for MTHFR (rs1801133) polymorphism was performed by TaqMan assay.
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). High intake of folate, vitamin B2 and vitamin B6 was a protective factor 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.
These results indicate that dietary methyl donors decrease the risk of asthma and atopy, which may be modified by MTHFR polymorphism.
This study was supported by a grant of the Environmental Health Center and Children’s Health and Environmental Research funded by the Ministry of Environment, Republic of Korea
Asthma, Sensitization, Folate, Methyl donors, MTHFR, Polymorphism