This study explored the relationship between diet-derived antioxidants and asthma using data from the 2003-2018 National Health and Nutrition Examination Survey (NHANES) and a two-sample Mendelian randomization (MR) study. The results showed a negative correlation between the dietary intake of vitamin C, zinc, selenium, and CDAI (a combined antioxidant index) and asthma risk. Specifically, higher intakes of these antioxidants were associated with a reduced likelihood of having asthma, with significant nonlinear relationships observed for vitamin C, zinc, and selenium. Participants with asthma were typically young-to-middle-aged females, smokers, of non-Hispanic Black ethnicity, with a lower income, and a BMI over 30.
However, while the observational analysis indicated a negative association between diet-derived antioxidants and asthma, the MR study found no causal link between lifelong circulating antioxidant levels and asthma risk. The sensitivity analyses confirmed the robustness of the observational findings but did not support a direct causal relationship. Overall, while dietary antioxidants may be inversely related to asthma risk, further research is needed to clarify whether they play a causal role in asthma development.
Reference: Chen L, Chen C, Lin M, et al. Association between diet-derived antioxidants and asthma: Insights from the NHANES survey 2003-2018 and Mendelian randomization analysis. Heart Lung. 2025 Jan-Feb;69:71-77. doi: 10.1016/j.hrtlng.2024.09.014. Epub 2024 Oct 1. PMID: 39357290.
