Association between dietary anthocyanin intake and chronic obstructive pulmonary disease in US adults: A public database survey

Background: Anthocyanins have anti-inflammatory and antioxidant properties. Several studies have demonstrated that anthocyanins are associated with many chronic diseases, but few studies have focused on the relationship between anthocyanins and chronic obstructive pulmonary disease (COPD). Objectives: This survey aimed to explore the relationship between dietary anthocyanin intake and COPD in US adults over the age of 40. Methods: A cross-sectional study from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 was conducted. We used univariate and multivariate logistic regression and restricted cubic spline (RCS) to analyze the relationship between dietary anthocyanins and COPD. Subgroup and interaction analyses were adopted to assess whether there were differences in the relationship between dietary anthocyanin intake and COPD in different groups. Results: A total of 2862 participants aged >= 40 years were analyzed, of whom 213 were diagnosed with COPD. The highest tertile of dietary anthocyanin intake was negatively correlated with COPD compared to the lowest after adjusting potential confounders (Model 1, OR = 0.414; 95% CI: (0.245, 0.699), P-trend = 0.002; Model 2, OR = 0.363; 95% CI: (0.210, 0.627), P-trend = 0.002; Model 3, OR = 0.614; 95% CI: (0.383, 0.985), P-trend = 0.040). The RCS curve showed a significant inverse linear relationship between dietary anthocyanin intake and COPD (P non-linear = 0.734). In subgroup analyses, the negative correlation between dietary anthocyanin intake and COPD existed across different subgroups. Conclusion: Our study indicated that higher dietary anthocyanins are a protective factor against the presence of COPD in the US aged over 40.