Mediterranean pregnancy: how mothers' varied diet reduced the risk of atopic dermatitis in children

If you eat a varied diet during pregnancy and are closer to the Mediterranean style, your child under two years of age is less likely to develop atopic dermatitis (AD). This is the conclusion reached by Swiss and German researchers who analyzed the diet of expectant mothers and the skin condition of their children as part of the CARE cohort. In their new work in Nutrients, they did not find any benefit from “hunting” for individual nutrients, but they did see the effect of dietary patterns and dietary diversity.

Background

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease in young children: it debuts in every fifth to third child, often in the first two years of life, often opening the "atopic march" (allergic rhinitis, asthma). The development of AD is influenced by both non-modifiable factors (genetics of the skin barrier, such as filaggrin mutations) and modifiable factors - the environment and nutrition during critical windows of fetal and infant development. The DOHaD concept ("Developmental Origins of Health and Disease") suggests that maternal diet during pregnancy can "reconfigure" the child's immune system and the maturation of the skin barrier through metabolites, microbiota and epigenetic mechanisms.

In recent years, the focus of research has shifted from individual nutrients (omega-3, vitamin D, probiotics) to dietary patterns. The reason is simple: food components do not act alone, but in combination - fiber and polyphenols feed the microbiota and increase the level of short-chain fatty acids; omega-3 and monounsaturated fats modulate inflammation; a variety of plant foods expands the spectrum of antigens and metabolites associated with the formation of immune tolerance. Against this background, the Mediterranean diet - rich in vegetables, fruits, legumes, whole grains, fish, nuts and olive oil with moderate consumption of red meat and highly processed foods - is considered a realistic, safe and nutritionally rich model for pregnancy.

At the same time, evidence has accumulated that the strategy of “avoiding allergenic foods during pregnancy” does not prevent allergies in the child and may even limit dietary diversity, depriving the mother and fetus of beneficial nutrients. Confounding factors are also important: antibiotics during pregnancy, family history of atopy, smoking, socioeconomic status - so studies need to be properly statistically adjusted. In this context, studies that evaluate the overall dietary pattern and dietary diversity in relation to early clinical outcomes in children (for example, the risk of AD at age two) are especially valuable in order to move from the “hunt for individual vitamins” to practical, applicable recommendations for expectant mothers.

Who and how was studied

• 116 mother-child pairs from the CARE birth cohort. Maternal diet during pregnancy was assessed with a validated 97-item food frequency questionnaire (FFQ) and several indices were calculated, including the Mediterranean Dietary Score and a dietary diversity index (how many different items from the questionnaire the woman actually ate).
• In children, AD diagnosis/symptoms were assessed at 4 months, 1 year, and 2 years, and models were adjusted for key factors: total caloric intake, child's gender, maternal antibiotics during pregnancy, and family history of atopy in both parents.

The result was remarkable: the closer the diet is to the Mediterranean pattern and the wider the palette of products, the lower the risk of AD in a child by the age of two. But the bet on the percentage of proteins/fats/carbohydrates or individual microelements did not justify itself - no associations were found.

What we found - in numbers

• Mediterranean diet: Women with a score above the median (>3) had a lower risk of having BP in their child (aOR 0.24; 95% CI 0.08-0.69; p=0.009) compared with the lower half.
• Dietary diversity: in the group with a higher number of different foods (above the median, >53 FFQ items), the risk was even lower (aOR 0.19; 95% CI 0.06-0.58; p=0.005).
• It didn’t work: the proportions of macro- and microelements, independent of the pattern, were not associated with blood pressure.
• An interesting signal: higher red meat consumption was associated with persistent AD phenotype in the first 2 years (aOR 5.04; 95% CI 1.47-31.36; p=0.034).

Why is that? The authors remind us: a dietary pattern is not a simple sum of nutrients. The Mediterranean diet brings vegetables, fruits, legumes, whole grains, fish, olive oil, i.e. fiber, polyphenols, omega-3 and monounsaturated fats in stable combinations. Diversity is also a broad "training" of the developing child's immune system through the mother's microbiome and metabolites that affect the formation of the skin barrier and innate immunity. A separate capsule with the "right" nutrient will not replace such synergy - and this is reflected in the results.

What does this mean in practice?

• Pregnant women (and those who are just planning a pregnancy) should focus not on the percentage of proteins, fats, and carbohydrates, but on a balanced, varied “Mediterranean” diet with an emphasis on plant sources, fish, and high-quality fats.
• Variety is the key: rotate vegetables/fruits/grains/legumes throughout the week, rather than repeating the same set.
• Red meat does not necessarily have to be eliminated entirely, but the results suggest that moderation and dietary context matter, especially if the goal is to support skin barrier maturation and immune tolerance in the unborn child.
• In real life, the frequency and composition of the diet should be discussed with a doctor/nutritionist, taking into account individual deficiencies, tolerance and medical indications.

Despite their optimism, the researchers are honest about their limitations. The sample size is small (n=116, Switzerland), maternal diet is self-reported (FFQ), and there is a risk of residual confounding (e.g., education level, physical activity, environmental factors). This is an observational study: it shows associations, not causation. But the signal is consistent with earlier data on the benefits of a Mediterranean pregnancy pattern for allergic outcomes in children. The next step is larger cohorts and randomized interventions to test causality and the “dose” of variation.

Context of the study

• The paper is part of a special issue of Nutrients on diet and allergy in early life, funded by CK-CARE (Davos). Deadlines: submitted 14 June, accepted 3 July, published 7 July 2025.
• In their models, the authors carefully took into account familial atopy and antibiotics during pregnancy - factors that often “shift the arrows” in allergology.
• Interestingly, the pictures of the distribution of BJU in mothers (inserts to the article) show that many met national recommendations for macronutrients - but it was the pattern and variety that turned out to be predictors of the child's outcome.

Conclusion

Rather than hunting for individual vitamins, building a rich and varied "Mediterranean plate" during pregnancy is exactly the approach that was linked in this study to a lower risk of atopic dermatitis in the child by age two.

Source: Heye KN et al. Diet Diversity and Adherence to a Mediterranean Diet Pattern in Pregnancy Is Protective Against the Development of Early-Childhood Atopic Dermatitis. Nutrients, 7 July 2025. https://doi.org/10.3390/nu17132243