Flavonoids, a diverse group of polyphenolic compounds found in many fruits and vegetables, have been studied for their potential role in supporting or treating diabetic retinopathy (DR). Several preclinical and clinical studies suggest that flavonoids possess antioxidant, anti-inflammatory, and vasoprotective properties, which are relevant to the pathogenesis of DR—a complication of diabetes characterized by retinal blood vessel damage due to chronic hyperglycemia.

Scientific evidence indicates that flavonoids such as quercetin, rutin, and epigallocatechin gallate (EGCG) can help reduce oxidative stress and inflammation in retinal tissues. Animal models have demonstrated a reduction in retinal vascular leakage, inhibition of neovascularization, and protection of retinal cells after flavonoid administration. Some small-scale clinical trials and observational studies have reported improvements in retinal blood flow and a reduction in the progression of early DR with flavonoid supplementation.

However, large, well-controlled randomized clinical trials in humans are lacking. The current evidence base is promising but not definitive, and most recommendations for flavonoid use in DR are based on mechanistic plausibility and preliminary clinical data. As such, flavonoids are considered as adjunctive or supportive agents rather than primary therapies for diabetic retinopathy. Further research is needed to clarify their efficacy and optimal usage.