Grape polyphenols, particularly flavonoids, have a wide variety of effects including antioxidant, vessel widening, and anti-clotting properties that promote circulation and enhance vein health. Preliminary evidence also suggests grape seed OPCs may provide greater protection against reactive oxygen species, free radical-induced lipid degradation, and DNA damage as compared to using a combination of vitamin E, vitamin C, and beta-carotene. Overall, OPCs work to promote a healthy immune response to normal oxidative and metabolic stress.