Infants with broader diets in first year less likely to develop atopic dermatitis, study finds

A large South Korean study suggests that infants who eat a wider range of foods in their first year may have a slightly lower risk of developing atopic dermatitis later in childhood, highlighting the potential importance of early dietary variety.

Researchers in South Korea say that infants who eat a narrower range of foods in their first year of life may face a slightly higher risk of developing atopic dermatitis later in childhood, adding to a growing body of evidence that early dietary variety could matter for allergic disease.

In a nationwide study published in Pediatric Allergy and Immunology, Ju Hee Kim and colleagues at Kyung Hee University College of Medicine in Seoul analysed health data from 267,935 children born in 2009 and 2010. The team drew on the Korean National Health Insurance Service database and classified food diversity at 12 months as low, moderate or high, while excluding infants who had already been diagnosed with atopic dermatitis in order to reduce the chance that early symptoms altered feeding patterns.

Most of the children were in the higher-diversity group, with 56.8% classed as high, 35.5% as moderate and 7.6% as low. According to the study, the lower-diversity groups were more likely to develop atopic dermatitis than children who had a broader diet at 12 months. After adjustment, the hazard ratio was 1.08 for the low-diversity group and 1.11 for the moderate-diversity group, compared with the high-diversity group. The researchers reported no meaningful difference by sex or by maternal history of asthma or atopic dermatitis.

The findings fit with earlier work suggesting that broader early feeding may be linked to fewer allergic conditions later on. Research published previously in journals including Pediatrics, the Journal of Allergy and Clinical Immunology and the European Respiratory Journal has associated greater food diversity in infancy or the second year of life with lower rates of asthma, food allergy, allergic rhinitis and atopic dermatitis by school age. At the same time, a systematic review from the US Nutrition Evidence Systematic Review programme said evidence remains limited on whether dietary diversity itself changes the risk of eczema and related disorders.

The new study does not prove that a more varied infant diet prevents eczema, but it strengthens the case for further testing. The authors said the results support an association between diverse complementary feeding and lower risk of atopic dermatitis, while emphasising that randomised controlled trials are still needed before public health advice can be based on cause and effect.