Methyl donor intake during first trimester affected childhood asthma risk

Women whose dietary intake included methyl donors during the first trimester of pregnancy possibly reduced the risk for their children developing asthma, according to research presented at the American Thoracic Society International Conference in San Diego.

“Evidence on the effects of dietary methyl donor intake on childhood asthma has been mixed,” researcher Michelle Trivedi, MD, clinical fellow in pediatric pulmonology, Massachusetts General Hospital for Children, Boston, said in a news release. “It has been suggested that folate enrichment of some foods may have contributed to increasing asthma and allergy prevalence in the US.

Michelle Trivedi

“We found that maternal intake of the six methyl donors we studied — folate, choline, betaine, and vitamins B2, B6 and B12 — had protective effects on the risk of developing childhood asthma, and that interactions between these nutrients affected the magnitude and the direction of this risk.”

Trivedi and colleagues used food frequency questionnaires in the first and second trimester to measure dietary and supplemental intake in 1,052 mother-child pairs. The six nutrients were assessed, with and without supplementation. Physician-diagnosed asthma at age 7 years was the primary outcome. Adjustments for age, BMI, asthma, education and household income of the mother, and birth weight, sex, race/ethnicity, breastfeeding duration, environmental tobacco smoke exposure and eczema of the child were determined through multivariable logistic regression.

There were 219 children (20.8%) diagnosed with asthma. Sixty-eight percent of children in the study were Caucasian; 13.6%, African-American; 3.6%, Hispanic; 3.2% Asian; and 11.6%, other race/ethnicity.

Lower asthma prevalence was associated with higher intake of folate, choline, vitamin B2 and betaine in univariate models. When adjusted, reduced prevalence was associated with dietary choline and vitamin B12 without supplementation in the first trimester.

“Considering that these nutrients are in the same one-carbon metabolism pathway, we created a single model combining all six nutrients together along with the other covariates of interest,” the researchers wrote.

Vitamin B6 (OR=1.52; 95% CI, 1.04-2.21) and dietary choline (OR=0.72; 95% CI, 0.56-0.93) displayed significant association with childhood asthma in the combined model.

“Our results suggest that dietary intake of folate and other methyl donors during pregnancy does not increase the risk of asthma and may, in fact, decrease the risk of offspring developing asthma,” Trivedi concluded. “Further study is warranted to dissect potential mechanisms.”

For more information:

Trivedi M. #54675. Presented at: 2014 American Thoracic Society International Conference; May 16-21; San Diego

Disclosure: Trivedi reports no relevant financial disclosures.