There is a growing body of scientific evidence suggesting that anthocyanins, the flavonoid pigments responsible for the red, purple, and blue colors in many fruits and vegetables, may support the management of diabetic retinopathy. Diabetic retinopathy is characterized by microvascular damage in the retina due to chronic high blood glucose levels, leading to oxidative stress, inflammation, and vascular permeability.

Several preclinical studies have demonstrated that anthocyanins possess strong antioxidant and anti-inflammatory properties. These properties help to reduce oxidative stress in retinal tissues, inhibit the expression of inflammatory cytokines, and protect against endothelial dysfunction. For example, studies using anthocyanin-rich extracts from bilberries and blackcurrants have shown protective effects against retinal damage in animal models of diabetes. Some clinical studies, though limited in number and scale, have also suggested that supplementation with anthocyanin-rich extracts may help improve visual function and decrease retinal vascular leakage in people with diabetic retinopathy.

However, high-quality, large-scale randomized controlled trials in humans are still lacking, and the current clinical evidence is not yet strong enough to recommend anthocyanins as a primary therapeutic intervention for diabetic retinopathy. Nevertheless, the mechanistic rationale and preclinical data provide moderate support for their adjunctive use, justifying a mid-level evidence rating.