Anthocyanins, a class of flavonoid compounds found in deeply colored fruits and vegetables (such as blueberries, blackcurrants, and red grapes), have been investigated for their potential benefits in supporting vascular health, including the treatment and prevention of varicose veins. The rationale for their use is primarily based on their antioxidant, anti-inflammatory, and vasoprotective properties. Several clinical and preclinical studies suggest that anthocyanins may strengthen capillary walls, improve microcirculation, and reduce vascular permeability, which are relevant mechanisms in the management of chronic venous insufficiency and varicose veins.

A number of trials, particularly with anthocyanin-rich extracts like Vaccinium myrtillus (bilberry) and Vitis vinifera (grape seed), have demonstrated improvements in symptoms such as leg swelling, heaviness, and discomfort in patients with chronic venous disorders. However, most studies are of modest size and vary in methodological quality. Systematic reviews and meta-analyses have found that flavonoids, including anthocyanins, can provide moderate symptomatic relief for chronic venous insufficiency, though there is still a need for larger, high-quality randomized controlled trials to confirm these effects specifically for varicose veins.

In summary, while the scientific evidence is not definitive, it is suggestive enough to support the use of anthocyanins as an adjunct in the management of varicose veins, particularly for symptomatic relief, earning a moderate evidence rating.