Spanish researchers have found that ultra-processed foods may be a direct risk factor for asthma in children. Using the NOVA food classification system, the study’s authors found that the greater the share of ultra-processed foods in a child’s diet, the higher the likelihood of developing asthma.
According to a study published in the journal Allergy, children who consumed more than 30% of their daily calories from ultra-processed foods — including carbonated soft drinks, packaged snacks and sweetened breakfast cereals — had nearly four times the risk of developing asthma during the preschool years.
Notably, the researchers found that these foods were associated with asthma, but not with classic allergic conditions. Instead, they appear to trigger a specific type of inflammation in the lungs.
How the study was conducted
The study followed nearly 700 children ages 4 and 5 over a four-year period as part of the SENDO (Seguimiento del Niño para un Desarrollo Óptimo) project.
Parents completed detailed dietary questionnaires, and the research team classified the children’s food intake using the NOVA system, which categorizes foods according to their level of processing rather than their nutrient content.
Parents also reported annually whether their children had been diagnosed with asthma or allergic conditions.
To improve the reliability of the findings, the researchers adjusted for several potential confounding factors, including the children’s weight and the amount of time they spent in front of screens.
Key findings
The study found a strong association between higher consumption of ultra-processed foods and an increased risk of asthma.
Specifically, greater consumption of NOVA Group 4 ultra-processed foods was significantly associated with a higher risk of developing asthma over the five-year study period. However, the researchers found no significant association between ultra-processed food consumption and atopy, atopic dermatitis, neuroallergic sensitization or food allergies.
The authors said the findings underscore the need for public health strategies that encourage healthier diets in children as a way to help prevent respiratory diseases.
Why asthma but not allergies?
The researchers suggested that ultra-processed foods may contribute to lung inflammation through mechanisms that are independent of allergic reactions. That could explain why the study found a link with asthma but not with other allergic diseases.
