Every parent knows how difficult it can be when a baby cries for hours without an obvious reason. Feeding, changing diapers and comforting them sometimes seem to make little difference, leaving exhausted parents wondering what could be wrong.
For some families, the situation becomes even more challenging when the baby also develops eczema, causing dry, irritated and itchy skin.
Now, researchers have discovered that what a mother eats during pregnancy may be associated with whether her baby develops both conditions.
According to a new study published in JAMA Network Open on October 12, 2026, women who followed a Mediterranean-style diet during pregnancy were less likely to have babies who experienced both colic and eczema.
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The research, conducted by scientists from Harvard T.H. Chan School of Public Health, Boston Children's Hospital and Harvard Pilgrim Health Care Institute, involved more than 1,300 mothers and their children.
One particular food appeared especially interesting: seafood.
Researchers followed more than 1,300 mothers and babies
The researchers examined information from 1,324 mother-child pairs who participated in Project Viva, a long-running American study investigating how health and lifestyle during pregnancy may affect children.
The women were originally recruited from prenatal clinics in Massachusetts between 1999 and 2002. They completed questionnaires about their eating habits during pregnancy, allowing researchers to examine how frequently they consumed different foods.
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When the babies were approximately six months old, the researchers collected information about whether they had experienced colic, eczema or both conditions.
Colic generally refers to frequent, prolonged crying in an otherwise healthy baby, often without an obvious explanation. It can be extremely stressful for parents, particularly when the crying continues despite repeated attempts to comfort the child.
Eczema, meanwhile, is an inflammatory skin condition that can cause dry, itchy and irritated patches. According to the American Academy of Pediatrics, the condition is associated with problems in the skin's protective barrier and can be influenced by both genetics and environmental factors.
In the Harvard-led study, approximately 26 percent of babies experienced colic, while around 5 percent developed both colic and eczema.
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When researchers compared these outcomes with their mothers' diets, a clear pattern emerged.
A Mediterranean diet was linked to 15% lower odds
Women whose diets more closely resembled the Mediterranean eating pattern were less likely to have babies who developed both conditions.
The Mediterranean diet emphasizes vegetables, fruits, whole grains, beans, nuts, olive oil and other healthy fats. Fish and seafood also play an important role, while processed foods, sugary drinks and large amounts of red meat are generally limited.
Researchers used a scoring system to measure how closely each mother's diet followed this pattern.
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For every one-point increase in the Mediterranean Diet Score, the odds of a baby developing both colic and eczema were approximately 15 percent lower.
Interestingly, the opposite pattern appeared among mothers whose diets scored higher on a measure of dietary inflammatory potential.
Each one-point increase on that scale was associated with 34 percent higher odds of the baby experiencing both conditions.
The score reflected eating patterns involving greater consumption of foods such as refined grains, processed meat and sugary drinks. It did not directly measure inflammation in the mothers or their babies.
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However, the researchers discovered something important: the association was specifically linked to babies who experienced both colic and eczema.
They did not find a clear association between the overall dietary scores and either condition when examined separately.
That distinction matters because the research does not establish that a Mediterranean diet prevents colic or eczema in general.
One food showed a particularly interesting connection
When researchers examined individual foods, seafood stood out.
According to an announcement from Harvard T.H. Chan School of Public Health, each additional weekly serving of seafood during pregnancy was associated with approximately 25 percent lower odds of a baby developing both colic and eczema.
This finding was based on the mothers' reported average seafood consumption during pregnancy.
Seafood contains several nutrients important for fetal development, including protein, iodine and omega-3 fatty acids. Some of these nutrients support normal brain development and other essential biological processes.
Researchers are interested in whether prenatal nutrition may also influence the development of a baby's immune system and the communication between the digestive system and brain.
However, the study did not establish which nutrients, if any, explained the seafood association.
It also did not prove that eating another portion of fish each week would directly reduce a particular baby's risk by 25 percent. The figure describes a statistical association, not a guaranteed protective effect.
Nevertheless, the finding adds to existing evidence supporting the importance of a balanced diet during pregnancy.
Why colic and eczema together caught the researchers' attention
Although colic and eczema are different conditions, scientists believe there may sometimes be connections between them.
Colic is primarily associated with excessive crying during early infancy, while eczema affects the skin. However, both have been studied in relation to immune-system development and allergic conditions.
Previous research has suggested that babies who experience colic may have higher rates of certain allergic conditions later in childhood.
Dr. Jenifer Lightdale, a pediatric gastroenterologist at Boston Children's Hospital and the study's corresponding author, explained that the researchers were particularly interested in babies experiencing both conditions.
They wanted to investigate whether maternal eating habits during pregnancy could be associated with this combination, rather than looking only at symptoms appearing after birth.
The researchers also found that the associations between diet quality and infant symptoms were generally stronger among mothers with a history of allergic conditions.
These included conditions such as asthma, hay fever and eczema.
This raises the possibility that maternal diet could interact with a child's inherited susceptibility to allergic or inflammatory conditions.
However, the researchers did not establish a biological mechanism, and more studies will be needed to understand why the association appeared stronger in certain families.
What about eggs, dairy and nuts during pregnancy?
The scientists also investigated several foods commonly associated with allergies.
These included milk and other dairy products, eggs, peanuts, tree nuts, fish and shellfish.
The findings were not the same for every food.
Dairy and egg consumption were not clearly associated with colic or eczema outcomes in the study. Nut consumption also showed no clear association with babies developing both conditions together.
The researchers did observe a small, borderline association between higher nut consumption and colic without eczema. However, that finding was less certain and does not establish that eating nuts during pregnancy causes colic.
Importantly, the study does not provide evidence that pregnant women should avoid common food allergens to prevent either condition.
Avoiding entire food groups unnecessarily can make it more difficult to obtain the nutrients needed during pregnancy.
Women with diagnosed food allergies or specific medical conditions should continue following advice from their healthcare professionals.
How much fish should pregnant women eat?
The findings are particularly relevant because health authorities already encourage pregnant women to consume appropriate amounts of fish.
The US Food and Drug Administration (FDA) recommends that pregnant and breastfeeding women eat approximately 8 to 12 ounces of lower-mercury fish each week.
That is equivalent to around 225 to 340 grams, or two to three adult servings.
The agency identifies several suitable options, including salmon, sardines, cod, shrimp, trout and canned light tuna.
For example, someone could include salmon with vegetables for dinner, a serving of cod later in the week and a meal containing shrimp.
However, choosing the right fish is important because some species contain high levels of mercury, which can affect the developing nervous system of an unborn baby.
The FDA advises pregnant women to avoid high-mercury species such as swordfish, shark, king mackerel, marlin and bigeye tuna.
Pregnant women should also avoid raw or undercooked seafood because of the risk of foodborne infections. The FDA's pregnancy food safety guidance recommends cooking fish thoroughly to reduce the risk from harmful bacteria and parasites.
The new research does not change these established recommendations. Instead, it offers another potential reason to consider seafood as part of a balanced pregnancy diet.
The study has an important limitation
Although the findings are encouraging, researchers emphasize that the study cannot establish cause and effect.
The mothers were not randomly assigned to follow different diets. Instead, scientists examined what the women reported eating and compared those habits with their babies' later symptoms.
This means other factors could partly explain the results.
For example, women who follow Mediterranean-style diets may also differ in their healthcare access, education, lifestyle or other characteristics that influence pregnancy and infant health.
The researchers accounted for several possible influences, including maternal age, education, smoking and history of allergic conditions, but that cannot eliminate every potential difference.
Another limitation is that only 61 babies in the study developed both colic and eczema. That relatively small number makes it particularly important to confirm the findings in larger populations.
The dietary information was also collected from pregnancies between 1999 and 2002, even though the analysis was published in 2026.
More recent studies involving different populations would help determine whether the same associations can be consistently reproduced.
Healthy eating matters, but perfection is not the goal
For pregnant women, the findings may be encouraging, but they should not become another source of pressure.
Eating a Mediterranean-style diet does not guarantee that a baby will avoid colic, eczema or other health problems. Both conditions can develop for reasons unrelated to what a mother eats.
The research also does not suggest that women need expensive ingredients or a completely different diet to support a healthy pregnancy.
Simple choices such as including more vegetables, choosing whole grains, eating beans and incorporating suitable fish can form part of a nutritious eating pattern.
Emily Oken, the study's first author and a professor at Harvard T.H. Chan School of Public Health, also emphasized that healthy eating is not equally accessible to everyone.
She noted that financial difficulties and other barriers can make nutritious food harder to obtain, even when families are motivated to make healthy choices.
The researchers hope the findings will support not only individuals but also programs designed to improve access to healthy food during pregnancy.
For now, the study offers a potentially important insight into how maternal nutrition may be connected to infant health.
It does not mean that a particular meal can prevent a baby's discomfort. But it suggests that dietary patterns during pregnancy may be worth investigating as part of the complicated relationship between nutrition, immune development and early childhood health.
And for women already following a balanced diet that includes vegetables, whole grains and appropriately prepared, lower-mercury seafood, the findings provide another encouraging reason to continue those habits.
This article is made and published by Aksel Kryhlmand, who may have used AI in the preparation.