Unhealthy Diet Linked to T17-High Asthma in Puerto Rican Youth

Dietary Influences on Asthma Subtypes in Youth

Asthma is increasingly understood not as a single disease, but as a heterogeneous syndrome composed of distinct biological subtypes, or endotypes, each driven by unique inflammatory pathways [1, 2]. This clinical variability may be influenced by modern lifestyle factors, including dietary patterns, which are known to shape immune system development and function [3, 4, 5, 6]. Differentiating asthma by its underlying mechanism, such as the T helper 2 (T2)-high or T helper 17 (T17)-high endotypes, offers a more precise framework for understanding disease and developing targeted interventions [7]. However, the specific relationship between diet and these asthma endotypes in pediatric populations has remained unclear. A recent study in Puerto Rican youth, a population with a high asthma burden, sought to clarify how dietary choices might associate with specific inflammatory pathways of the disease.

Investigating Diet and Asthma Endotypes

To explore the link between diet and asthma subtypes, researchers utilized a robust study design involving Puerto Rican children and adolescents. The investigation included both a cross-sectional analysis of 465 participants and a prospective, longitudinal analysis of 358 of those individuals. This dual approach allowed for a snapshot of associations at a single point in time as well as an examination of how dietary habits influenced asthma endotypes over a mean interval of 5.3 years. Participants entered the study between ages 6 and 14 and were followed up at ages 9 to 20. Diet was assessed via a food frequency questionnaire, which was used to generate a dietary score from -2 (unhealthiest) to +2 (healthiest); an unhealthy diet was defined as any nonpositive score (-2 to 0). At the second visit, asthma endotypes were determined not by symptoms, but by analyzing the expression of eight signature genes in nasal epithelial cells, a method that provides a biological fingerprint of the underlying immune response. This classified participants with asthma into three groups: T2-high, T17-high, and T2-low/T17-low. The statistical relationship between diet and these distinct outcomes was then analyzed using multinomial regression, a technique suited for assessing risk factors when there are more than two categorical results.

Cross-Sectional Associations with T17-High Asthma

The initial cross-sectional analysis of 465 participants revealed a significant association between diet quality and the T17-high asthma endotype. This subtype of asthma is often characterized by neutrophilic inflammation, which can be less responsive to standard corticosteroid therapies. The study found that healthier eating habits appeared protective. Specifically, each one-point increment toward a healthier dietary score was associated with a 28% reduction in the odds of having T17-high asthma (odds ratio [OR]=0.72, 95% confidence interval [CI]=0.55-0.95, P=0.02). This suggests a potential dose-response relationship, where incremental dietary improvements may lower risk. Conversely, consuming an unhealthy diet was linked to a pronounced increase in risk. An unhealthy diet, defined by a score of zero or less, was associated with more than double the odds of T17-high asthma compared to controls (OR=2.31, 95% CI=1.31-4.08, P<0.01). For clinicians, these findings highlight diet as a potentially modifiable factor directly correlated with the prevalence of a specific, often hard-to-treat, asthma subtype.

Longitudinal Findings: Persistent Unhealthy Diet and Asthma Endotypes

Moving beyond a single snapshot, the prospective analysis of 356 youths provided insight into the long-term effects of sustained dietary patterns. The results demonstrated that a persistently unhealthy diet, documented at both the baseline and follow-up visits, was strongly associated with the development or maintenance of specific asthma endotypes over time. The most striking finding was that an unhealthy diet at both visits was associated with a more than four-fold increase in the odds of T17-high asthma (OR=4.30, 95% CI=1.77-10.47, P<0.01). This robust association suggests that chronic dietary habits, rather than short-term food choices, may play a significant role in driving this particular inflammatory pathway. Furthermore, the analysis identified a potential link between a persistently unhealthy diet and the T2-low/T17-low endotype, which often lacks clear biomarkers of allergic inflammation. This association approached statistical significance (OR=2.48, 95% CI=0.99-6.20, P=0.05), indicating another area for future investigation. These longitudinal data reinforce to clinicians that dietary counseling is not just about immediate symptom management but may be a critical tool for modifying the long-term biological trajectory of asthma in children and adolescents.

Clinical Implications and Future Directions

This study provides compelling evidence that dietary patterns are not just generically linked to asthma, but are specifically associated with the T17-high endotype in Puerto Rican youth. The findings bridge a critical knowledge gap, suggesting that T17-mediated inflammatory pathways may be a key mechanism through which diet influences asthma pathogenesis. The cross-sectional analysis showed that an unhealthy diet was associated with increased odds of T17-high asthma (OR=2.31, 95% CI=1.31-4.08, P<0.01), an association that grew substantially stronger in the prospective analysis. In that cohort, a persistently unhealthy diet was linked to markedly higher odds of T17-high asthma (OR=4.30, 95% CI=1.77-10.47, P<0.01). For practicing physicians, these data elevate the clinical importance of dietary assessment and counseling. The results suggest that nutritional interventions could be a valuable, non-pharmacologic strategy to help manage or potentially prevent T17-driven asthma, a subtype that can be challenging to control. By identifying a modifiable risk factor for a specific biological subtype, this research supports a move toward more personalized asthma care, where nutritional guidance may become an integral component of treatment, especially for high-risk pediatric populations.

References

1. Wang J, Zhou Y, Zhang H, et al. Pathogenesis of allergic diseases and implications for therapeutic interventions. Signal Transduction and Targeted Therapy. 2023. doi:10.1038/s41392-023-01344-4

2. Fainardi V, Passadore L, Labate M, Pisi G, Esposito S. An Overview of the Obese-Asthma Phenotype in Children. International Journal of Environmental Research and Public Health. 2022. doi:10.3390/ijerph19020636

3. Li R, Li J, Zhou X. Lung microbiome: new insights into the pathogenesis of respiratory diseases. Signal Transduction and Targeted Therapy. 2024. doi:10.1038/s41392-023-01722-y

4. Özdemir C, Küçüksezer UC, Öğülür İ, et al. Lifestyle Changes and Industrialization in the Development of Allergic Diseases. Current Allergy and Asthma Reports. 2024. doi:10.1007/s11882-024-01149-7

5. Song X, Liang J, Lin S, et al. Gut‐lung axis and asthma: A historical review on mechanism and future perspective. Clinical and Translational Allergy. 2024. doi:10.1002/clt2.12356

6. Liu L, Zhao W, Zhang H, Shang Y, Huang W, Cheng Q. Relationship between pediatric asthma and respiratory microbiota, intestinal microbiota: a narrative review. Frontiers in Microbiology. 2025. doi:10.3389/fmicb.2025.1550783

7. Öğülür İ, Mitamura Y, Yazıcı D, et al. Type 2 immunity in allergic diseases. Cellular and Molecular Immunology. 2025. doi:10.1038/s41423-025-01261-2