Mediterranean diet adherence and its association with inflammatory and oxidative stress biomarkers in asthma

The Mediterranean diet (MD) is known for its anti-inflammatory and antioxidant properties, yet its role in asthma pathophysiology remains underexplored. This study aimed to investigate the association between adherence to the MD and systemic markers of eosinophilic inflammation and oxidative stress in adult patients with bronchial asthma.

In this cross-sectional study, 86 adult asthma patients from a university outpatient clinic were assessed. Anthropometric measurements, Asthma Control Test (ACT) scores, and dietary habits (via the MedDiet score) were collected. Oxidative stress and antioxidant capacity were evaluated using the d-ROM (derivatives of reactive oxygen metabolites) test and PAT (plasma antioxidant test), respectively. Blood eosinophil percentage and absolute count were also measured.

The majority of patients (83.7%) exhibited moderate adherence to the MD, while only 8.1% demonstrated high adherence. Higher MedDiet scores were significantly associated with lower eosinophil percentages (r = -0.322, p < 0.01) and counts (r = -0.254, p < 0.05), and greater antioxidant capacity (PAT) in patients with severe asthma (r = 0.339, p = 0.047). Full-fat dairy intake was positively associated with oxidative stress (d-ROM), while fruit and olive oil consumption were linked to enhanced antioxidant levels. No significant differences in oxidative stress were observed between asthma severity groups.

Greater adherence to the MD is associated with lower systemic eosinophilic inflammation and enhanced antioxidant capacity in asthma patients. The data indicate that dietary interventions could serve as complementary strategies in asthma care, particularly for severe cases, and that oxidative-stress associations were present and strongest among patients with severe asthma.