Berry Anthocyanins and Their Metabolites in Endothelial Dysfunction Associated with Diabetes and Cardiometabolic Risk

Diabetes-related endothelial dysfunction involves oxidative stress, impaired nitric oxide (NO) signaling, and inflammation. Because ingested berry anthocyanins undergo extensive metabolism, circulating conjugates and phenolic products may contribute to vascular responses. This critical narrative review searched MEDLINE/PubMed, Web of Science, and Scopus through 1 July 2026 and examined citation trails. Among 298 database records, 253 were unique. The screening log selected 29 reports for full-text assessment; 26 were included and three excluded after full-text analysis. Four reports entered through citation tracking. The 30 included reports comprised eight cell-based, twelve animal or mixed, and ten human reports; two human reports analyzed related participants. Experimental studies associated berry preparations or metabolites with lower measured reactive oxygen species, NADPH oxidase (NOX) expression, and inflammatory markers, sometimes alongside preserved NO signaling or vascular relaxation. Expression changes do not establish NOX inhibition or nuclear factor kappa B (NF-κB)-dependent mediation. Several small phenolic products lack anthocyanin-specific provenance. Human vascular findings in cardiometabolic risk populations were mixed, and no included berry intervention in established diabetes used a direct endothelial endpoint. Current evidence supports mechanistic plausibility but does not establish clinical efficacy in diabetes or attribute whole-berry effects to anthocyanins alone.