Washington Post

Babies Fed a Diverse Diet Had Fewer Food Allergies, Study Reports

REUTERS/Kim Kyung-Hoon/ File Photo
A woman holding a baby stands in front of a shelf displaying milk powder products at a supermarket in Beijing May 20, 2013.

The Washington Post

11:55 JST, March 6, 2025

A diverse diet that introduced 13 or 14 foods to 9-month-old babies was associated with a 45 percent lower risk of food allergy compared with the introduction of fewer foods at that age, according to a study in the journal Pediatric Allergy and Immunology.

Researchers used data from 2,060 infants and their families – recruited between May 2016 and December 2022 – in the NorthPop Birth Cohort Study, a population-based study in Northern Sweden that seeks to identify factors influencing allergies and asthma.

The new research also said infants with the most diverse diet had a 61 percent lower risk of having a food allergy by 18 months than those with the least diverse diet. A diverse diet was particularly effective in preventing a food allergy for those without a family history of food allergies or history of eczema. But earlier introduction of a diverse diet, at 6 months, did not show the same reduction in food allergy risk.

Parents filled out food consumption questionnaires when their children reached about 9 months of age. Diet diversity was measured by the frequency of the infants’ consumption of 14 foods at 6 and 9 months, as well as how often the infants consumed six allergenic foods (wheat, egg, fish, dairy, nuts and peanuts, and soy).

At 18 months, 100 children participating in the study were diagnosed with a food allergy. The most commonly occurring were cow’s milk allergy (69 cases) and egg allergy (35 cases). Additionally, 30 of the 100 had allergies to multiple foods.

Food allergies are generally inherited, the researchers said, but infant diet can have an impact on the adaptive immune system and allergic disease development.

“Repeated exposure to foods in infancy is important both for tolerance development and maintenance,” the authors write. “One could assume that frequent consumption of plant-based foods including fruit, vegetables, and legumes which are rich in fiber and vitamins are especially important for reducing food allergy risk, in line with existing guidelines.”