A U-shaped association between composite dietary antioxidant index and migraine in US adults: a nationwide cross-sectional study.

Background: The field of dietary therapies for migraine has grown in popularity. Less research has been conducted to establish the relationship between migraine and the composite dietary antioxidant index (CDAI), a crucial indicator for evaluating the overall combined effects of multiple dietary antioxidants. Therefore, this study addressed this gap based on the National Health and Nutrition Examination Survey (NHANES) database.

Methods: Multivariate logistic regression equations were used to investigate the relationship between CDAI and migraine, and smoothed-fitted curves were plotted. After a nonlinear relationship was discovered, the recursive algorithm and a two-stage linear regression model were employed to calculate the turning point. Additional stratified analyses were performed to explore differences between populations.

Results: This study included a total of 9,190 participants aged 20 years old or older. A U-shaped association was observed between the CDAI and migraine, with an inflection point of 0.2. They were negatively correlated before the inflection point with OR of 0.93 (95% CI = 0.88-0.97) and positively correlated after the inflection point with OR of 1.04 (95% CI = 1.01-1.07). This U-shaped relationship persisted among people aged <60 and ≥60 years, women, and people with BMI <30 and ≥30.

Conclusions: We identified a U-shaped association between CDAI and migraine in the U.S. adult population. Further case-control studies and experimental research are needed to explore the underlying mechanisms of action.