Mediterranean diet during pregnancy cuts babies’ food allergy risk

A Greek study links Mediterranean-style eating during pregnancy and breastfeeding to a lower incidence of food allergies in children, highlighting the significant impact of maternal diet on shaping early immune health.

Study: Adherence to Mediterranean Diet During Pregnancy, Breastfeeding, and Development of Food Allergy in the Offspring: Results From the MEDALLION Cohort Study. T.Vyc / Shutterstock

In a recent study published in the journal Allergy, researchers assessed associations between maternal adherence to the Mediterranean diet (MedDiet) during pregnancy and lactation and the development of food allergy (FA) in the offspring, reporting borderline inverse associations for overall MedDiet adherence in both periods (pregnancy adjusted OR 0.94, 95% CI 0.89–1.00; breastfeeding adjusted OR 0.94, 95% CI 0.88–1.00).

FAs have increasingly become a public health concern over the past decades, with prevention regarded as a promising strategy to decrease the burden of FAs. Immunoglobulin E (IgE)-mediated FA is the most common, with a prevalence of 8%–10% in Western countries. By contrast, its prevalence in developing countries is highly variable.

Urbanized areas in China exhibit rates similar to those in the West, whereas rural regions in Africa and Asia have significantly lower prevalence rates. This suggests that factors such as diet, age, and environment influence the prevalence of FAs. Maternal diet during pregnancy and lactation has gained substantial attention in this context, given its influence on the fetal immune system.

About the Study

In the present study, researchers evaluated the effects of the MedDiet during pregnancy and lactation on FA development in early life. The Mediterranean Allergy Prevention (MEDALLION) study was a large, retrospective cohort study that followed mothers from six regions in Greece: Athens, Alexandroupoli, Crete, Ioannina, Peloponnese, and Thessaloniki. Mothers of infants with FA and those of healthy controls were enrolled.

An interview was conducted post-enrolment to gather information on demographics, parental history of allergies, siblings’ atopic history, birth weight, gestational age, mode of delivery, and maternal antibiotic use during pregnancy. In addition, information was collected on maternal diet during pregnancy and lactation, smoking habits, complementary feeding practices, antibiotic use, and family history of allergies.

A sub-cohort of mother-child dyads from Athens, Ioannina, and Thessaloniki was formed based on the following criteria: exclusive breastfeeding for at least two months and completion of the MedDiet score questionnaire at enrollment. Physician-diagnosed FA cases included both IgE- and non-IgE-mediated phenotypes (159 and 177, respectively). The present study analyzed data from the sub-cohort. A follow-up MedDiet score questionnaire was administered to infants at 24–36 months of age; data on allergic conditions, antibiotic exposure, parental smoking, and feeding practices were also collected.

The MedDiet score questionnaire assessed the weekly intake of 11 food groups: potatoes, unrefined cereals, vegetables, legumes, fruits, red meat products, fish, full-fat dairy products, olive oil, poultry, and alcoholic beverages. Univariate analyses were performed to examine the effect of the MedDiet score and individual food groups on FA development. In multivariate analyses, logistic regression models assessed the associations between the MedDiet and FA while adjusting for maternal and paternal atopy history and maternal food exclusion during pregnancy/breastfeeding.

Findings

A total of 430 mothers with complete data were included in the analyses. Of these, 336 were mothers of infants with FA and 94 were mothers of healthy controls. About 31% of infants had a history of atopic dermatitis, 4% had wheezing, and 19% were prescribed anaphylaxis emergency kits. During pregnancy, 21% of mothers used antibiotics, 14% were smokers, and 13% excluded certain foods (e.g., milk, coffee, and sugar) from their diet.

Around 30% of mothers had a history of atopy. The MedDiet adherence was high during pregnancy and lactation. Mothers of healthy controls had significantly higher MedDiet scores than mothers of infants with FA. In univariate analyses, higher adherence to the Mediterranean diet during pregnancy and lactation was associated with lower (though borderline) odds of FA development in infancy.

During pregnancy, mothers of healthy controls had higher intakes of fruits, olive oil, and vegetables and lower intakes of fish, poultry, and red meat. During lactation, mothers of healthy controls consumed more vegetables, whereas mothers of infants with FA consumed more poultry and red meat products.

In multivariate analyses, higher adherence to the MedDiet during pregnancy and breastfeeding was inversely associated with the odds of FA in infancy. During pregnancy, consuming more than eight weekly servings of fruit and more than 15 servings of full-fat dairy reduced the risk of FA, while consuming more than one serving of fish per week and more than three servings of poultry or red meat increased the risk. During lactation, consuming more than 12 weekly servings of vegetables was protective, while consuming more than three weekly servings of poultry or red meat increased the risk.

Conclusions

Maternal adherence to the MedDiet during pregnancy and lactation was associated with lower odds of FA in infancy, although confidence intervals bordered unity, and causality cannot be inferred. Certain food groups exhibited both risk-enhancing and protective associations. That is, high maternal consumption of fruits, vegetables, and full-fat dairy products reduced the odds of FA in infants, while high intakes of red meat, fish, and poultry may increase the risk.

The finding of an increased risk associated with fish intake contrasts with some previous studies that suggested a protective effect, and the authors note potential confounding factors from environmental pollutants in fish. Overall, the results support the potential of maternal nutrition to reduce childhood FA, warranting prospective intervention trials and replication in non-Mediterranean settings.

Limitations include retrospective design, reliance on maternal recall, case–control imbalance, and potential residual confounding, which may limit generalizability.