Exploratory Food-Frequency Scores and Self-Reported Asthma in Italian Adults: A Nationwide Cross-Sectional Study

Background: Associations between diet and asthma in adults remain uncertain. Objective: To examine associations between two exploratory food-frequency scores and self-reported asthma. Methods: We analysed public-use data from the 2023 Italian Aspects of Daily Life survey. The PRO and ANTI scores summarised selected food frequencies; neither was a validated measure of dietary inflammatory potential. Survey-weighted logistic models were adjusted for age group, sex, education, body mass index, smoking, and household economic resources. Continuous and tertile specifications were fitted separately; an additional model included both continuous scores. Results: Among 33,182 adults with asthma information, weighted prevalence was 4.62% (95% CI 4.37–4.89). The regression sample included 32,000 adults and 1460 asthma cases. In the mutually adjusted model, PRO was not associated with asthma (OR per 10 points 1.004, 95% CI 0.952–1.059), whereas ANTI was inversely associated (OR 0.947, 95% CI 0.907–0.989). ANTI tertile comparisons did not reach conventional statistical significance. Sex-specific and restricted-sample analyses were exploratory. Conclusions: A modest inverse association was observed for the continuous ANTI score, but evidence was sensitive to exposure parameterisation. These cross-sectional findings do not demonstrate reduced asthma risk, respiratory benefit, or an inflammatory mechanism. Replication with validated dietary assessment and clinically characterised asthma is needed.