A new long‑term study suggests that children who consume higher levels of ultra‑processed foods may face a significantly greater risk of developing asthma. The results, which are detailed in the paper, “Ultra-Processed Food Consumption and Childhood Allergic Diseases: Increased Risk of Asthma Onset in the SENDO Project,” are raising concerns among public health experts.
Researchers analyzed data from the SENDO project — a multi‑year, cohort study following Spanish children — and found that dietary patterns, particularly the consumption of ultra‑processed foods (UPFs), could play a much larger role in childhood respiratory health than previously understood. Their findings were published in the European journal, Allergy.
The study tracked more than 1,500 children recruited between 2015 and 2024, focusing on those aged four to five years at the start. After excluding participants with preexisting conditions, researchers analyzed a final group of 691 children with an average age of 3.4 years.
Participants were divided into three groups based on how much ultra‑processed food they consumed. The findings revealed a clear pattern:
- Children with the lowest intake had an asthma risk of 2.6%.
- Children with moderate intake showed a risk of 9.9%.
- Those with the highest intake had a risk of 7.6%.
Children consuming higher levels of ultra‑processed foods had nearly a fourfold increase in asthma risk compared to those with healthier diets.
The study’s authors noted that asthma rates have been rising globally, particularly in industrialized countries, and although genetics remain an important factor, research increasingly points to lifestyle influences — especially diet — as a critical contributor.
Ultra‑processed foods, which include items like packaged snacks, sugary drinks and fast food, are often high in saturated fats and low in fiber. According to the study, these foods may trigger low‑grade chronic inflammation, which can affect the airways and potentially lead to asthma.
Scientists who conducted the study said they believe this process involves biological pathways that activate inflammatory responses in the body, including the release of cytokines that increase airway sensitivity and damage respiratory tissue over time.
Although the link between ultra‑processed foods and asthma was strong, researchers did not find similar connections with other allergic conditions, such as food allergies, atopic dermatitis (eczema) or allergic rhinitis. This suggests that diet‑related inflammation may influence asthma through different biological mechanisms than those driving traditional allergic diseases, they said.
The study also found that children who consumed more processed foods tended to have other lifestyle factors that could contribute to health risks, including:
- Higher screen time
- Lower physical activit
- Higher body mass index (BMI)
- Lower rates of breastfeeding
- Less parental awareness of nutritional recommendations
These findings reinforce the idea that diet is part of a broader pattern of behaviors that influence long‑term health, authors noted.
Although researchers emphasized the study does not prove causation, they said the longitudinal design strengthens confidence in the findings because it shows diet patterns preceded asthma development.
Importantly, they added, the study identified a dose‑response relationship, meaning that as consumption of ultra‑processed foods increased, so did asthma risk — an indicator often associated with real biological effects.
Still, researchers cautioned that asthma is a complex condition influenced by multiple factors, including
- Genetics
- Air pollution
- Tobacco exposure
- Infections
With ultra‑processed foods becoming increasingly common in children’s diets worldwide, researchers said their findings raise urgent questions for policymakers and parents alike, suggesting that limiting processed foods could be a modifiable risk factor, offering an opportunity for prevention.
The study’s authors noted that more work is needed to confirm the findings across different populations and to better understand the biological mechanisms involved. They recommended future studies to explore the role of the gut microbiome and inflammatory markers in linking diet to respiratory conditions.
