You are not what your mother eats: Maternal diet during lactation

Are you what your mother eats?
The first 1,000 days of life—from conception to age two—are critical for a child’s health. Nutrition during this time shapes growth, immunity, and gut health. While much attention has been given to diet during pregnancy, less is known about whether maternal diet while breastfeeding influences baby’s risk of developing allergies.
This research explored whether a mother’s diet during lactation influences her baby’s risk of developing eczema or food allergies. Using data from the PRIMA birth cohort, which followed over 1000 mother-infant pairs in the Utrecht region, we studied up to 272 mothers’ diets and their babies’ health during the first year of life.
Based on previously published studies, we generated a systematic summary and observed that the consumption of complex fatty acids like omega-3 fatty acids relates to the level of those fatty acids in breast milk. Our own analysis showed mothers’ diet is relatively stable during the first months postpartum, with the exception for some product groups, despite mother’s breastfeeding or work status. We did not observe that adherence to dietary guidelines, intake of allergenic foods (specifically eggs, milk(products), (pea)nuts), or omega-3 fatty acids associated with their babies’ risk of eczema and possible food allergies. The strongest predictor of infant eczema and food allergy symptoms in our analysis was family history, in line with findings of others.
We also examined complex fiber-like sugars in breast milk, human milk oligosaccharides (HMOs), known to support immunity. The level of a specific type of glycated HMOs in breast milk did not depend on maternal dietary fiber consumption, but mostly on maternal genetics (specifically Secretor status). Nevertheless, lab experiments with different profiles of these sugars dependent on mother’s Secretor status suggest that both mother’s and baby’s genetics may influence immune responses in the presence of these oligosaccharides, and should receive intention in further research.
In short, in our study population, we did not find an association between maternal diet during breastfeeding and eczema and food allergy symptoms during the first year of life. Supporting breastfeeding and healthy eating remains important for other health benefits. Additional research is needed to understand the impact of this for infant’s risk of allergic diseases.