Flavonoid intake, inflammation, and atherosclerotic cardiovascular disease risk in U.S. adults: a cross-sectional study.

Background: This study aimed to investigate the relationship between the dietary intake of total flavonoids and their six subclasses and the risk of atherosclerotic cardiovascular disease (ASCVD) in adults, and to evaluate the potential mediating effect of inflammation in this association.

Methods: Cross-sectional data from 3841 individuals participating in the National Health and Nutrition Examination Survey 2017-2018 were included in the analysis. Flavonoid intake was assessed using a 2-day dietary recall method, and ASCVD status was determined by extracting relevant information from the medical condition questionnaire. To determine the relationship between flavonoid intake and ASCVD risk, we employed logistic regression, subgroup, mediation, and restricted cubic spline analyses.

Results: Intake of flavan-3-ols, flavones, flavonols, and total flavonoids was negatively correlated with ASCVD risk. Subgroup analysis revealed that the association between flavonoid intake and ASCVD risk exhibits sex-specific differences, with the relationship being more pronounced among women. The significant associations between increased flavonoid intake and reduced ASCVD risk were observed in smokers, non-alcohol consumers, physically inactive individuals, those with hypertension. A nonlinear relationship was observed between the intake of total flavonoids, flavan-3-ols and flavonols and ASCVD risk. Additionally, high-sensitivity C-reactive protein (hs-CRP) and the neutrophil-to-lymphocyte ratio (NLR), inflammatory markers relevant to ASCVD, were found to mediate the association between flavonoid intake and ASCVD risk. Flavonoids demonstrated a dose‒response relationship with reductions in the levels of hs-CRP and the NLR.

Conclusions: This study indicates the inverse association between flavonoid intake, particularly flavan-3-ols, flavones, and flavonols, and the risk of ASCVD. It highlights the mediating role of CRP and NLR in this relationship. Furthermore, the study emphasizes the importance of considering lifestyle factors and sex when evaluating the cardiovascular benefits of flavonoids.