Adopting a Mediterranean diet—rich in fruits, vegetables, olive oil, and fish—may significantly lower the risk of developing asthma as an adult, according to a new study published in Respirology. Researchers followed over 17,000 adults in Spain for nearly 13 years and found those with the highest adherence to this dietary pattern had a 42% lower risk of asthma onset compared to those with the lowest adherence. This research adds to a growing body of evidence suggesting that what we eat can play a crucial role in preventing chronic respiratory diseases.
The study, conducted by researchers at the University of Navarra, focused on participants in the long-running SUN Project (Seguimiento Universidad de Navarra), a prospective cohort study examining the health of university graduates in Spain. The SUN Project, established in 1999, has been instrumental in investigating the relationship between diet and various health outcomes, including cardiovascular disease and cancer. As detailed in a 2025 cohort profile update published in the International Journal of Epidemiology, the project continues to provide valuable insights into the long-term effects of lifestyle factors on health. Researchers analyzed dietary habits using a validated food frequency questionnaire, assessing adherence to the Mediterranean diet using a Mediterranean Diet Score (MDS), ranging from 0 to 9.
Understanding the Mediterranean Diet and Asthma Risk
Whereas the link between diet and asthma has been explored before, particularly in children, the evidence for adults has been less conclusive. The Mediterranean diet, characterized by a high intake of plant-based foods, healthy fats, and fish, is known for its anti-inflammatory properties. Chronic inflammation is a key component of asthma, a condition affecting an estimated 262 million people worldwide, according to the World Health Organization. The diet’s potential benefits extend beyond inflammation, offering cardiometabolic advantages as well. This new study sought to clarify whether these benefits translate into a reduced risk of developing asthma in adulthood.
Participants in the SUN Project were initially free of airway disease. Over the 12.8-year follow-up period, 302 individuals (1.76%) reported a new diagnosis of asthma, based on self-reported physician diagnoses collected through biennial questionnaires. Researchers then used sophisticated statistical models—multivariable repeated-measurement Cox regression—to analyze the relationship between diet and asthma risk, carefully adjusting for factors that could influence the results, such as age, sex, smoking status, and physical activity levels.
Key Findings: A Significant Protective Effect
The analysis revealed a significant inverse association: the more closely participants followed a Mediterranean diet, the lower their risk of developing asthma. Specifically, individuals in the highest adherence group (MDS ≥7) experienced a 42% reduction in asthma risk compared to those in the lowest adherence group (MDS ≤2). This finding is statistically significant, with a hazard ratio of 0.58 (95% Confidence Interval: 0.36–0.95. p-trend=0.02). This suggests a strong and consistent protective effect of the Mediterranean diet against adult-onset asthma.
The researchers emphasize that this is the first prospective study in a Mediterranean population to demonstrate this protective association. Previous studies have often been cross-sectional, meaning they looked at diet and asthma at a single point in time, making it difficult to determine cause and effect. The prospective design of the SUN Project—following participants over time—provides stronger evidence for a causal link between diet and asthma risk.
What Does This Mean for Asthma Prevention?
The findings support the idea that dietary patterns are modifiable risk factors for chronic respiratory diseases. While genetic predisposition and environmental factors play a role in asthma development, lifestyle choices, including diet, can also have a significant impact. Promoting Mediterranean-style eating habits could be a valuable component of asthma prevention strategies, particularly for individuals at higher risk of developing the condition.
However, it’s vital to note that this study doesn’t prove that the Mediterranean diet *causes* a reduction in asthma risk. It demonstrates a strong association, but further research is needed to fully understand the underlying mechanisms. It’s also crucial to remember that asthma is a complex condition with multiple contributing factors, and diet is just one piece of the puzzle.
The research team plans to continue analyzing data from the SUN Project to explore the specific components of the Mediterranean diet that may be most protective against asthma. Future studies could also investigate whether dietary interventions can help manage asthma symptoms in individuals already diagnosed with the condition. The full study findings are available in Respirology, published online February 2026, DOI: 10.1002/resp.70200.
Disclaimer: This article provides information for general knowledge and informational purposes only, and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
The growing evidence linking diet to respiratory health underscores the importance of a holistic approach to wellness. As researchers continue to unravel the complexities of asthma, dietary interventions may offer a promising avenue for prevention and management. Share this information with others who may benefit from learning about the potential benefits of a Mediterranean diet.
