Association Between Dietary Tomato Intake and Blood Eosinophil Count in Middle-Aged and Older Japanese Individuals: A Population-Based Cross-Sectional Study †

Background/Objectives: Although tomato consumption has been associated with positive health outcomes, it remains unclear whether it can prevent or exacerbate allergic diseases by regulating eosinophils. We explored the association between dietary tomato intake and blood eosinophil counts in Japanese individuals. Methods: This population-based, cross-sectional study included 1013 participants aged ≥ 40 years. The dietary intake of tomatoes was assessed using a validated, self-administered diet history questionnaire. The peripheral blood eosinophil count was measured, and an elevated blood eosinophil count was defined as a value that exceeded the ≥75th percentile. Results: The mean age of the participants was 62.5 ± 11.2 years, with 474 (46.8%) being male. Overall, 252 participants exhibited elevated blood eosinophil counts (≥204/μL). In the multivariable logistic regression model with adjustment for potential confounders, an increase in tomato intake of 10 g was inversely associated with an elevated blood eosinophil count (odds ratio [OR], 0.895; 95% confidence interval [CI], 0.834–0.961). Except for chronic kidney disease, the baseline participant characteristics did not influence this association. Conclusions: Low dietary tomato intake was associated with an elevated blood eosinophil count in middle-aged and older Japanese individuals. These results may provide insight into the dietary management of eosinophil-related allergic and type 2 inflammatory diseases.