Maternal nutrition during pregnancy and lactation is raising the risk of food allergies (FA). FA is a rapidly growing public health issue, and several preventive methods have been well-established to reduce its impact. The most common type of FA is IgE-mediated, primarily affecting newborns and young children, with an incidence of 8% to 10% in Western countries. Environmental factors appear to play a greater role than genetics in the development of FA, while about half of children with atopy reported a family history.
Exposure to passive or active tobacco smoke has been repeatedly associated with a higher incidence of childhood allergy disorders. The Mediterranean Diet (MedDiet) promotes the development of a healthy gut flora and immunological tolerance, including fruits, vegetables, legumes, and monounsaturated fats. Breast milk contains dietary proteins in very low amounts, up to 1000 times less than natural human milk proteins. This supports the concept of gradual low-dose exposure and may explain the rarity of allergic responses to breast milk proteins.
In Greece, the Mediterranean Allergy Prevention (MEDALLION) cohort study followed 2,306 women from six separate locations. This study aimed to examine the relationship between the risk of developing FA during infancy, maternal diet, and early life exposures. Mothers with pre-existing chronic conditions related to breastfeeding were not considered in this research.
The MEDALLION trial included 1,515 mothers of healthy controls and 791 mothers of infants with a physician-diagnosed FA. For continuous variables, means and standard deviations were reported, while interquartile ranges (IQR) were used for categorical variables. The relationship between the MedDiet adherence and FA was evaluated using multivariate analysis that accounted for known confounders.
A MEDALLION sub-cohort included 336 mothers of infants with FA and 94 mothers of healthy infants. In terms of feeding, 24 babies received amino acid-based formula, and 81 infants received partially hydrolysed formula. A total of 61 infants received completely hydrolysed formula, and 97 infants received formula based on cow’s milk. Among the mothers, 66 reported smoking during lactation, while 68 reported removing certain foods from their diet. Participants in this sub-cohort showed strong adherence to the MedDiet during both pregnancy (32.4 ± 4.4) and lactation (33.0 ± 4.3). Higher adherence to the MedDiet by women throughout pregnancy [odds ratio (OR) 0.94, 95% confidence interval (CI) 0.89-0.99] and lactation (OR 0.93, 95% CI 0.87-0.98) was reported by univariate logistic regression analysis. Mothers with FA tend to eat more chicken and red meat, whereas mothers in good health consume more vegetables. The increased risks of FA were linked to large consumption of fish during pregnancy, as well as chicken and red meat across both periods.
The study suggested that greater weekly intake of fruits and vegetables during lactation and whole-fat dairy products during pregnancy may help lower the risk of FA. Possible explanations for differences between these findings and those of previous prospective cohort studies may reflect the variations in research design. Overall, the results highlighted the importance of further studies on dietary interventions to define better the role of traditional dietary patterns in preventing FA early in life.
References: Vassilopoulou E, Karastogiannidou C, Comotti A, et al. Adherence to Mediterranean diet during pregnancy, breastfeeding, and development of food allergy in the offspring: results from the MEDALLION cohort study. Allergy. 2025:1-10. doi:10.1111/all.70054
