In a recent study published in the World Allergy Organization Journal, researchers examined the relationship between asthma occurrence and intake of dietary zinc among children and adolescents overweight and obesity, utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2020.
The study suggests that higher dietary zinc intake is associated with a reduced risk of asthma in this population, highlighting the potential role of zinc in mitigating asthma risk among children and adolescents.
Study: Association between dietary zinc intake and asthma in overweight or obese children and adolescents: A cross-sectional analysis of NHANES. Image Credit: Danijela Maksimovic / Shutterstock
Background
Childhood asthma, a prevalent respiratory condition, poses a growing global concern, with increasing rates among children and adolescents. This trend is compounded by the rising prevalence of obesity in this demographic, which exacerbates asthma symptoms and reduces treatment effectiveness.
Recent research has focused on the role of nutrients, particularly zinc, in asthma management due to its involvement in inflammation and oxidative stress regulation. Prior studies yielded inconsistent results regarding the association between asthma and zinc intake.
To address this gap, a study utilizing NHANES data examined the relationship between dietary zinc intake and asthma among overweight or obese children and adolescents, hypothesizing that asthmatic individuals in this group would have lower zinc intake than their healthy counterparts.
About the study
The study utilized data from NHANES, covering four survey cycles from 2011 to 2020, to investigate the relationship between asthma and dietary zinc intake among overweight or obese adolescents and children in the United States.
Participants under 20 years old were included, with those having incomplete data or falling under the categories of underweight or normal weight being excluded.
Asthma status was determined based on participants' self-reported history of diagnosis and recent asthma attacks. Dietary zinc intake was assessed through 24-hour dietary recall interviews and categorized into quartiles.
In multivariate logistic regression models, various potential covariates, including demographic factors, family history of asthma, and dietary factors, were considered and adjusted for.
Restricted cubic splines were used to analyze the relationship between zinc intake and asthma while controlling for these covariates.
Additionally, multivariate logistic regression analysis was performed to evaluate potential interactions between dietary zinc and other factors such as sex, age, and family history of asthma.
Sensitivity analyses were conducted to validate the robustness of the findings.
Findings
The final sample included 4,597 individuals, 20, with 963 reporting asthma. Participants with incomplete asthma questionnaires, incomplete dietary zinc intake data, or normal weight were excluded.
The median age was 11 years, and 20.9% of the participants were diagnosed with asthma; 49.6% reported their gender as male. Higher zinc intake was correlated with male gender, non-Hispanic white ethnicity, lower household income, absence of familial asthma history, and no dietary supplement use.
After controlling for various factors, including demographics and dietary intake, a significant inverse relationship was found between dietary zinc intake and asthma.
The adjusted odds ratios for asthma in the second, third, and fourth quartiles were 0.78, 0.76, and 0.71, respectively, compared to the lowest zinc intake quartile.
Stratified analyses showed no significant interactions, and sensitivity analyses confirmed the robustness of the findings. Furthermore, dietary zinc intake was inversely associated with recent asthma attacks and remained so after adjusting for asthma treatment.
These results suggest a consistent negative linear trend between the intake of dietary zinc and the risk of developing asthma in children and adolescents who are overweight or obese.
Conclusions
Researchers found a significant inverse association between dietary zinc intake and asthma risk, even after controlling for various factors such as demographics and dietary intake. This association remained robust across stratified and sensitivity analyses, indicating its reliability.
Previous research has shown inconsistent conclusions regarding the relationship between zinc levels and asthma, with most focusing on body fluid zinc levels rather than dietary intake.
However, the current study, focusing on dietary zinc intake in a large population of overweight or obese children and adolescents, demonstrated a clear inverse correlation with asthma risk.
The study highlighted potential pathways through which zinc may influence asthma, including its antioxidant properties, immunomodulatory effects, and anti-inflammatory effects. These mechanisms suggest that zinc could be a potential therapeutic target for alleviating asthma symptoms among people with overweight or obesity.
The study's strengths include its large sample size, focus on overweight or obese children and adolescents, and use of diverse statistical methods. However, limitations such as potential residual confounding effects, reliance on self-reported asthma diagnosis, and the cross-sectional design prevent causal inferences.
These results emphasize the importance of considering nutritional factors in asthma management and warrant further research into the therapeutic potential of zinc supplementation.
Future studies using prospective cohort designs and randomized controlled trials may shed further light on the causal effect of dietary zinc intake on alleviating asthma in this population.
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