To test the hypothesis that the Mediterranean diet can be a protective factor for current wheezing in preschoolers.

Questionnaires were completed by parents of 1784 preschoolers (mean age, 4.08 ± 0.8 years). Children were stratified according to whether they experienced wheezing (20.0%) or not in the previous year. A Mediterranean diet score was built according to the intake frequency of several foods.

Age, birth by cesarean section, low birth weight, exposure to livestock during pregnancy, antibiotic use in the first year of life, acetaminophen consumption in the previous 12 months, rhinoconjunctivitis, eczema, parental asthma and tobacco consumption, maternal educational level, maternal age, physical activity, cat at home, and Mediterranean diet were associated with current wheezing but not with obesity. In the multivariate analysis, eczema, rhinoconjunctivitis, paternal asthma, and acetaminophen consumption remained risk factors for current wheezing (adjusted odds ratio [aOR] = 2.35 [95% confidence interval (CI) = 1.2 to 4.8], 2.78 [95% CI =1.3 to 6.1], 3.89 [95% CI = 1.4 to 10.7], and 2.38 [95% CI = 1.2 to 4.6], respectively). Conversely, Mediterranean diet and older age remained protective factors (aOR = 0.54 [95% CI = 0.3 to 0.9] and 0.67 [95% CI = 0.5 to 0.9], respectively).

The Mediterranean diet is an independent protective factor for current wheezing in preschoolers, irrespective of obesity and physical activity.