Pregnant women who follow a Mediterranean-style diet and regularly eat seafood face a lower risk of having infants with colic and eczema, according to a Harvard-led study published on October 12, 2026, in JAMA Network Open.
A large observational study of mothers and babies in Eastern Massachusetts has identified a strong link between what a woman eats during pregnancy and the likelihood that her newborn will develop the distressing combination of infant colic and eczema. Researchers at the Harvard T.H. Chan School of Public Health, Boston Children’s Hospital, and the Harvard Pilgrim Health Care Institute found that while neither condition on its own showed a clear tie to maternal diet, infants whose mothers consumed a pro-inflammatory diet faced significantly higher odds of a double diagnosis. The research, titled Maternal Prenatal Diet and Colic and Eczema Among Infants,
was authored by Emily Oken, MD, MPH; Sheryl L. Rifas-Shiman, MPH; Karen M. Switkowski, PhD, MPH; Kari Nadeau, MD, PhD; and Jenifer R. Lightdale, MD, MPH, who served as the corresponding author. Published in volume 9, issue 10, article e2638472 of JAMA Network Open, the work received support from the National Institutes of Health under grant R01HD034568 as well as from a gift provided by an anonymous donor to the Harvard T.H. Chan School of Public Health.
Project Viva Data Reveals Diet Score Patterns
The findings draw on Project Viva, a long-running prebirth cohort study that recruited more than 1,300 pregnant women from prenatal clinics between April 1999 and November 2002. Participants completed detailed food questionnaires at about 10 weeks and again around 28 weeks of pregnancy. The research team evaluated these diets using two established instruments: the Mediterranean Diet Score and the Dietary Inflammation Index. Among the mothers enrolled in the study, participants averaged about 33 years of age, and roughly half were expecting their first child.
A high Mediterranean Diet Score reflected a diet rich in fruits, vegetables, whole grains, legumes, and healthy fats, alongside moderate intake of dairy and lean proteins. Conversely, a high Dietary Inflammation Index indicated heavy consumption of red or processed meats, sugar-sweetened beverages, sodium, and refined grains.
Out of 2,128 liveborn infants, researchers analyzed 1,324 mother-infant pairs with complete dietary and health records. The study revealed that 26 percent of the infants experienced colic, 152 had eczema alone, 273 had colic alone, and roughly 5 percent had both conditions.
Mediterranean Diet Lowers Risk of Infant Health Conditions
The two dietary measures pointed in opposite directions regarding infant health. Each additional point on the Mediterranean Diet Score correlated with a 15 percent lower probability of giving birth to an infant suffering from both conditions simultaneously. By contrast, a 34 percent rise in that same risk accompanied every single-unit increase on the Dietary Inflammation Index.
The researchers also investigated commonly allergenic foods, including peanuts, tree nuts, eggs, dairy, and seafood.
Seafood told a distinct story. Mothers averaged about 1.6 servings of fish and shellfish per week.
Seafood Fats May Protect Children Against Allergic Conditions
The authors noted that omega-3 fats found in seafood possess anti-inflammatory properties that may help protect children against allergic conditions. The investigations into maternal prenatal intake build on broader historical context regarding dietary guidance during pregnancy, following expert reviews from the American Academy of Pediatrics in 2019 and The Lancet in 2023 that examined food avoidance practices during pregnancy.
Our new study is the first to investigate how prenatal diet can influence colic, and in particular, the combination of colic and eczema,
corresponding author Jenifer Lightdale pointed out, while also highlighting her professional capacities as associate chief of the Division of Gastroenterology, Hepatology, and Nutrition at Boston Children’s Hospital and professor of Pediatrics at Harvard Medical School.
While U.S. dietary guidelines already encourage regular seafood consumption during pregnancy, adherence remains very poor.
we hope our study will prove useful not only for individuals and families, but also for programs and services that support women’s health and nutrition, including federal programs like WIC and SNAP and those administered by health plans and systems, as well as initiatives based on the principle that ‘food is medicine.’
Emily Oken, Harvard T.H. Chan School of Public Health
Because the investigation was observational, researchers recorded what women already ate rather than assigning specific diets, meaning the findings demonstrate an association rather than direct causation. Future research will explore how postnatal diet, including infant feeding choices and maternal intake during breastfeeding, relates to colic symptoms. Readers should consult qualified medical professionals for personal guidance rather than treating observational research findings as direct clinical advice.