Editorial NexoScience
A bowl of fruit at breakfast. A side of steamed vegetables with dinner. That small, unremarkable habit was linked to significantly lower odds of wheezing among more than 7,600 children and adolescents surveyed in central Iran, according to a new study published in the Journal of Health, Population and Nutrition.
The relationship between produce and asthma has puzzled researchers for years. Previous studies, conducted mostly in wealthier countries, have produced conflicting results: some found that eating more fruit protected children from wheezing, others found no effect once confounding factors were accounted for. The new research, part of the Global Asthma Network, set out to test whether the same pattern would hold in a population whose diet looks very different from the ones typically studied.
Kids who ate produce daily wheezed noticeably less. Researchers surveyed 7,667 children aged 6 to 7 and adolescents aged 13 to 14 in Yazd, a city in central Iran, using validated food-frequency questionnaires and the same asthma screening tools used in international studies (ISAAC/GAN). After adjusting for age, sex, body mass index, and screen time, children who ate fruit on most or all days were 37% less likely to have experienced wheezing in the past 12 months than those who rarely or never ate fruit (OR = 0.63, 95% CI 0.42-0.94). Regular vegetable eaters fared similarly, with 38% lower odds of wheezing (OR = 0.62, 95% CI 0.48-0.80). Children who ate both fruit and vegetables regularly saw the strongest effect: a 50% reduction in the odds of wheezing (OR = 0.50, 95% CI 0.31-0.82).
But the full picture is more complicated than a single headline number. Despite that drop in wheezing, the same children showed no significant difference in doctor-diagnosed asthma or in how often they used asthma medication. In other words, produce seemed to ease one specific respiratory symptom without changing the broader clinical picture of the disease. The authors point to antioxidants like vitamins C and E, flavonoids, and carotenoids as the most likely biological explanation: compounds that help calm airway inflammation and oxidative stress, two processes closely tied to asthma symptoms, without necessarily altering the underlying diagnosis.
Correlation, not proof, and the researchers say so themselves. The study is cross-sectional, meaning it captured a single snapshot in time rather than following children for years. That design cannot establish that eating more produce actually causes less wheezing, only that the two go together statistically. Diet was also self-reported through questionnaires, a method prone to recall bias, and the researchers could not control for factors like air pollution or household smoke exposure that are known to affect asthma risk. The authors themselves call for randomized trials to confirm the link.
Still, the finding lines up with a broader body of evidence. A related meta-analysis cited in the paper, pooling data from more than 40 studies, found that high fruit and vegetable intake was tied to a modest but consistent 9 to 10% reduction in asthma risk among children overall. Combined with mechanistic research pointing to fiber, antioxidants, and gut microbiome effects, the new data adds weight to public health guidance that already recommends more produce for children, even if wheezing specifically isn’t the reason parents usually hear.
The study, “The association between fruit and vegetable intake and the odds of asthma among children and adolescents,” was conducted by Kimia Rostampour and colleagues and published in the Journal of Health, Population and Nutrition (DOI: 10.1186/s41043-025-00820-7).
