Total dietary flavonoid intake and risk of cardiometabolic diseases: A dose-response meta-analysis of prospective cohort studies

Abstract

Several epidemiological studies have suggested that flavonoid intake is associated with a decreased risk of cardiometabolic disease. However, the results remained inconsistent and there is no dose-response meta-analysis for specific outcomes. We conducted a meta-analysis to synthesize the knowledge about their associations and to explore their dose-response relationships. We comprehensively searched the PubMed, Embase, and Web of Science databases for prospective cohort studies published up to December 1, 2021. Summary relative risks (RR) and 95% confidence intervals (CI) were pooled for the association between flavonoid intake and cardiometabolic disease. Evaluations of linear or nonlinear dose-response were presented by restricted cubic splines. We identified 47 articles, including 1,346 676 participants and 127,507 cases in this meta-analysis. The summary of RR per 500 mg/d increase in flavonoid intake was 0.93 (95% CI 0.88–0.98) for cardiovascular disease, 0.89 (95% CI 0.84–0.94) for diabetes, and 0.97 (95% CI 0.94–0.99) for hypertension, respectively. We also found a linearity dose-response association between total flavonoid intake and cardiovascular disease (p nonlinearity = 0.541), and diabetes (p nonlinearity = 0.077). Our finding based on quantitative data suggested that a higher level of flavonoid intake is beneficial for the prevention of cardiometabolic diseases.

Keywords:

• Flavonoids
• cardiometabolic diseases
• prospective cohort studies
• meta-analysis

Acknowledgments

We acknowledge all the authors and Prof. JL for methodological advice and help in modifying the meta-analysis.

Authors’ contributions

TL and JL conceived, designed, and performed the work; TL analyzed the data; TL, JL, YZ, YF, HH, LY, DH revised the manuscript.

Disclosure statement

TL, YZ, YF, HH, LY, DH, JL declare that they have no conflicts of interest relevant to the content of this review.

Additional information

Funding

The National Natural Science Foundation of China (Grant nos. 81402752 and 81673260), the Natural Science Foundation of Guangdong Province (Grant no. 2019A1515011183), the Science and Technology Development Foundation of Shenzhen (Grant no. JCYJ20190808145805515), and the SZU medical young scientists’ program (Grant no. 71201-000001) supported the study. The investigators are grateful to the dedicated participants and all research staff involved in the study.