Dietary antioxidant and inflammatory potential in asthmatic patients and its association with all-cause mortality.

Background: The occurrence and progression of asthma can be influenced by the components in food. Our study aims to determine whether dietary antioxidant and inflammatory potential are associated with the risk of mortality in asthma patients.

Methods: Participants from the 2001-2018 National Health and Nutrition Examination Survey (NHANES) aged 20 years and older with a diagnosis of asthma were included. Mortality status was obtained according to death certificate records from the National Death Index. The antioxidant and inflammatory potential of the diet was assessed using two widely used and dependable indices, Composite Dietary Antioxidant Index (CDAI) and Dietary Inflammatory Index (DII). Restricted cubic spline (RCS) regression was used to analyze the non-linear relationship between the two indexes and mortality. Multivariable Cox proportional risk models were used to estimate hazard ratio and 95% confidence intervals for mortality. Finally, the relationship between CDAI and DII was analyzed.

Results: A total of 4698 NHANES participants represented 23.2 million non-institutionalized residents of the US were enrolled in our study. Patients with higher CDAI or lower DII exhibited longer survival times. RCS regression showed a linear relationship of CDAI or DII with mortality. In the Cox regression, both crude and adjusted models demonstrated that higher CDAI or lower DII was linked to a reduced risk of all-cause mortality. Similar associations were found in subgroup analysis. Finally, a negative relationship was found between CDAI and DII.

Conclusion: Reducing pro-inflammatory or increasing antioxidant diets could reduce all-cause mortality among adult asthma patients.