Mediterranean diet linked to lower asthma and rhinitis risk

Mediterranean diet adherence was associated with a 16% lower odds of asthma (11 studies; log OR: -0.18), a 25% lower odds of wheezing (6 studies; log OR: -0.29), and a 42% lower odds of rhinitis (log OR: -0.54); all confidence intervals excluded zero, indicating statistical significance. In contrast, eczema showed no meaningful association (log OR: 0.09, confidence interval included zero). Protective effects were stronger in Mediterranean populations than in non-Mediterranean regions. The studies included were observational and interventional designs with moderate heterogeneity. Food allergy could not be analyzed quantitatively due to insufficient data across studies. The authors emphasize that while these findings suggest a population-level benefit of Mediterranean diet adherence for respiratory allergic conditions, further longitudinal studies with standardized methods are needed to establish whether the diet causally prevents allergies or merely correlates with healthier lifestyles.

The protective effect was most pronounced for rhinitis (42% lower odds), followed by wheezing (25%) and asthma (16%), suggesting the diet's anti-inflammatory properties may particularly benefit upper and lower airway conditions. Heterogeneity was moderate, meaning individual studies varied in design, population, and outcome measurement—a reminder that effect sizes are average estimates, not universal. Mediterranean regions (Greece, Spain, Italy) showed stronger protective associations than non-Mediterranean populations, which could reflect either diet quality differences, genetic ancestry, environmental allergen exposure, or confounding lifestyle factors like physical activity. The null result for eczema is notable and suggests the diet's benefit may be specific to respiratory allergies rather than a broad anti-allergic effect. Publication bias was assessed but the authors note causality remains unproven; it is unknown whether the diet prevents allergies, or whether people with allergies and other health-conscious behaviors simply happen to adopt Mediterranean eating patterns.