One of Denmark’s largest studies to date shows that a mother’s diet during pregnancy can shape her child’s health well into adulthood. Fast food such as pizza and French fries appears to raise the risk of type 1 diabetes – most likely because such foods can disrupt the child’s developing immune system in the womb.
What a mother eats while pregnant does not just nourish her baby – it can shape the child’s health far into adult life.
A new study in Denmark clearly links a pro-inflammatory diet during pregnancy and the child’s later risk of developing type 1 diabetes.
The results suggest that eating large amounts of fast food and red meat acts like fuel on the fire – substantially increasing the risk.
Conversely, fruit and vegetables seem to protect: they dampen inflammation and lower the child’s long-term disease risk.
“When we talk about disease, we often focus on modifiable risk factors – and diet is one of them,” says Flemming Pociot, Professor and Chief Physician at Steno Diabetes Center Copenhagen in Denmark. “We cannot make recommendations based on a single study, but if the results are confirmed, they could help to guide dietary advice for pregnant women in families at increased risk of type 1 diabetes.”
The findings have been published in the Journal of Epidemiology and Community Health.
67,000 mothers reveal: an unhealthy diet raises the risk of type 1 diabetes
The research team conducted a large-scale prospective cohort study, following 67,701 mother–child pairs from the nationwide Better Health in Generations project for up to 18 years.
During pregnancy, the mothers filled in detailed dietary questionnaires, enabling the researchers to classify their intake into 38 food groups based on each food’s known potential to promote or reduce inflammation.
Each woman’s diet was then given an inflammation score. Foods such as fast food, red meat and sugary drinks raised the score – adding fuel to the inflammatory fire. In contrast, fruit, nuts, fish and berries lowered the score – extinguishing the flames.
The team used Denmark’s health registries to track the children’s health until age 18 years and could therefore explore how the mother’s diet during pregnancy related to the child’s later risk of developing type 1 diabetes.
They also assessed the possible influence of high gluten intake during pregnancy and of maternal smoking.
“For adults, a pro-inflammatory diet has been linked to higher risks of type 2 diabetes, cardiovascular disease and certain types of cancer. We aimed to determine whether the same pattern holds for type 1 diabetes among children,” says Rohina Noorzae, first author of the study, PhD student at Steno Diabetes Center Copenhagen in Denmark.
Fast food and red meat raise the risk – fruit and vegetables protect
Of the 67,701 children in the study, 281 developed type 1 diabetes before turning 18.
The researchers compared the children of mothers with the most pro-inflammatory diets to those whose mothers had more anti-inflammatory diets and found a 16% higher risk of type 1 diabetes. The effect remained even after adjusting for other factors such as maternal body-mass index and smoking.
Higher gluten intake during pregnancy was also linked to increased risk for the child, consistent with earlier research.
Surprisingly, the data showed that the children of mothers who smoked throughout pregnancy had a slightly lower risk of type 1 diabetes – a surprise also seen in previous studies. However, the researchers emphasise that smoking is still extremely harmful to both the mother and child, dramatically increasing the risk of many other diseases, so this should not lead to lighting a cigarette.
This pattern did not apply to mothers who quit smoking early in pregnancy – around week 12.
Only those who continued smoking throughout pregnancy had a lower risk.
“This finding is paradoxical,” says Rohina Noorzae, “but it certainly does not change the fact that smoking during pregnancy is a very bad idea. Smoking raises the risk of many other health problems for both mother and child – but apparently not type 1 diabetes.”
The immune system is programmed in the womb – and the mother’s diet plays a key role
According to Rohina Noorzae, the most plausible explanation is that a maternal pro-inflammatory diet creates a state of low-grade, chronic inflammation while the child’s immune system is still developing in the womb.
The researchers point to a biological mechanism: the child’s immune system is effectively programmed before birth. If it is constantly exposed to small alarm signals from the mother’s diet, it may learn to overreact – and later in life turn against the body’s own cells.
In particular, it may attack the insulin-producing cells of the pancreas – precisely what happens in type 1 diabetes.
“We do not yet know all the mechanisms behind the link between maternal diet and the child’s later risk of developing type 1 diabetes, but the connection is clear. An unhealthy, pro-inflammatory diet seems to increase the risk, whereas an anti-inflammatory diet appears protective. We cannot yet make official dietary recommendations based on this one study alone,” says Rohina Noorzae.
“But the message is clear: a mother’s diet during pregnancy does not just affect her own health – it can shape her child’s immune system and well-being for many years to come.”
