Westernized diet, characterized by high intakes of refined grains, red meat, processed food, and sugar is a risk factor for childhood asthma.

To investigate the effect of westernized diet during pregnancy and the interplay with social circumstances on development of childhood asthma, we investigated 586 mother?child pairs from the COPSAC2010 cohort with completed food frequency questionnaires (FFQ) from week 24 of pregnancy and longitudinal asthma outcomes until age 10yrs. Untargeted plasma metabolomics profiles were collected from week 24 of pregnancy, and child age 6mo, 18mo and 6yrs. The second principal component from the FFQ was representative of westernized diet and was used for selection of diet-related metabolites, using a sparse partial least squares regression model. Association with asthma outcomes was investigated using Cox and logistic regressions models.

In a confounder adjusted model, there was significant association between western diet FFQ score and child 18mo metabolome score and recurrent wheeze until age 6 (aOR=1.19 [1-1.4], p=0.04). For number of exacerbations until age 6 and asthma until age 10, there was significant interaction between western diet FFQ score and social circumstances (p-interaction=0.01) with increased risk related to low social circumstances. In stratified models, increasing western diet FFQ and child 18mo metabolome score was associated with higher risk of wheeze and exacerbations until age 6 and asthma until age 10, but only among children with low social circumstances (p <0.04). Significantly enriched pathways in the low social circumstances group were related to fatty acids, tryptophan, and vitamin A metabolism.