• Posted December 15, 2025

Mothers' Milk Might Be Key To Avoiding Childhood Food Allergies

Farm kids tend to have far fewer allergies than urban children, and a new study offers one possible explanation: The milk provided by breastfeeding moms.

Children who grow up in farming communities have immune systems that mature faster, with higher levels of protective antibodies during their first year of life, researchers reported Dec. 10 in Science Translational Medicine.

They’re getting these antibodies — and the immune cells that produce them — from their mothers’ milk, researchers say.

Researchers came to this conclusion studying infants from Old Order Mennonite farming families in New York’s Finger Lakes region.

“We’ve known that Old Order Mennonite children are remarkably protected from allergies,” said senior researcher Dr. Kirsi Järvinen-Seppo, chief of pediatric allergy and immunology at the University of Rochester Medicine’s Golisano Children’s Hospital.

“What this study shows is that their B cell and antibody responses are essentially ahead of schedule compared to urban infants,” she continued in a news release. “Their immune systems seem better equipped, earlier in life, to handle foods and other exposures without overreacting.”

For the new study, researchers compared 78 mother/child pairs from the Old Order Mennonite community with 79 moms and kids from urban and suburban Rochester. They followed the mothers and children through the first year of life, collecting blood, stool, saliva and human milk samples.

Results showed that farm-exposed babies had higher levels of immune cells, suggesting that their immune systems were more mature than those of city kids.

The researchers also found higher levels of antibodies in the human milk samples provided by their moms.

The research team then took a closer look at egg allergies, one of the most common food allergies in young children.

Farm children had higher levels of egg-specific antibodies in their blood, and mothers had higher levels of egg-specific antibodies in their breast milk, the study found.

Meanwhile, Rochester babies had varying levels of egg-specific antibodies in their blood, and this was linked to their risk for egg allergy. The more antibodies, the lower their risk of egg allergy.

“We saw a continuum: the more egg-specific antibodies in breast milk, the less likely babies were to develop egg allergy,” Järvinen-Seppo said. “We cannot prove causality from this study, but the association is compelling.”

Why did Mennonite moms have more of these egg-specific antibodies? Probably diet, researchers said.

Old Order Mennonite families typically raise their own chickens and eat a lot of eggs. That repeated exposure seems to boost mothers’ antibody levels against egg proteins, and they pass that protection on to their children through breast milk.

“Just as an infection or a vaccine can boost your antibody levels, regularly eating certain foods could do the same,” Järvinen-Seppo said. “Mennonite mothers eat more eggs, and that may help them pass more egg-specific antibodies to their babies through breast milk.”

Mennonite infants were also born with higher cord blood levels of antibodies to dust mites and horses, reflecting the environmental allergens to which their moms are regularly exposed, researchers said.

But Rochester babies had higher levels of antibodies to peanuts and cats, reflecting the more common allergen exposures of suburban and urban moms.

These results show why breastfeeding has not been consistently linked to a lower risk of food allergies, Järvinen-Seppo said, because it all depends on what a mom has been eating.

“Our data suggest there may be particular benefit when mothers have high levels of food-specific antibodies in their milk,” she said. “Not every mother does, and that could help explain why results have been mixed on the association between breast feeding and food allergy.”

However, mothers’ milk likely isn’t the only reason why farm kids have fewer allergies, Järvinen-Seppo said.

Daily exposure to farm animals and germs, drinking well water, less use of antibiotics and distinctly different patterns of gut bacteria all have been previously shown to also help shape the allergy resistance of rural children, researchers said.

They’re now conducting a clinical trial involving expecting mothers who will be assigned to either eat or avoid egg and peanut during late pregnancy and early breastfeeding. The team then will compare mothers’ antibody levels and their kids’ development of food allergies.

“We already know that introducing peanut and egg directly to babies early in life can lower allergy risk,” Järvinen-Seppo said. “Now we’re asking whether mothers’ diets during pregnancy and breastfeeding can add another layer of protection through the antibodies they pass to their babies. Ultimately, our goal is to translate what we learn from these communities into safe, practical strategies for all families.”

More information

The American College of Allergy, Asthma & Immunology has more on food allergies.

SOURCES: University of Rochester, news release, Dec. 9, 2025; Science Translational Medicine, Dec. 10, 2025