A systematic review of the mechanisms of cardiovascular disease reduction by dietary flavonoids: the impact of anthocyanins on flow-mediated dilation and blood rheology.

BACKGROUND: Epidemiological studies have suggested that anthocyanin, a dietary flavonoid found in a variety of foods, may protect against cardiovascular disease (CVD). The purpose of this review is to assess the effects of anthocyanin and anthocyanin-rich extracts on flow-mediated dilation (FMD), a vascular function marker, in healthy people and investigate their potential significance. METHOD: A thorough search of databases, including PubMed and Web of Science, was done to locate randomised controlled trials (RCTs) published before July 1st, 2024. The evaluation concentrated on English-language RCTs involving persons aged 20 to 65 years. Studies that did not examine anthocyanin or had insignificant results were eliminated. Data extraction comprised study characteristics, participant demographics, interventions, and results. The methodological quality of the included studies was assessed using the Cochrane Risk of Bias in Rob 2 tool. RESULTS: 15 studies out of 381 were found to meet the inclusion criteria. Anthocyanin-rich meals or extracts significantly improved flow-mediated dilation (FMD) (P < 0.05), with most studies reporting significant benefits within two hours of ingestion. However, some research found no significant differences, underscoring the diversity of the results. CONCLUSION: This comprehensive systematic review supports the idea that anthocyanin-rich foods or extracts can improve vascular function in healthy people, as evidenced by FMD. However, small sample sizes, varying anthocyanin doses, short intervention periods, and diversity in study methods limit the present body of evidence. Future studies should concentrate on well-powered, long-term randomised controlled trials using standardised anthocyanin formulations and dose regimens together with studies across varied demographics to improve generalisability in order to create unambiguous clinical guidelines.