Oligomeric proanthocyanidins or OPCs are a class of flavonoid complexes found in grape seeds and skin, that act as antioxidants (free radical scavengers) in the human body.

Thus, OPCs may help protect against the effects of internal and environmental stresses (that is, cigarette smoking, pollution, and supporting normal body metabolic processes). The effects are; depressing blood fat, emolliating blood vessels, lowering blood pressure, preventing blood vessel scleroses, dropping blood viscidity and preventing thrombus formation (a type of platelet clot).

Additionally, studies have shown that OPCs may prevent cardiovascular disease by counteracting the negative effects of high cholesterol on the heart and blood vessels.

A number of grape seed oil vendors have claimed that grape seed oil is high in OPCs. However independent studies have indicated that grape seed oil is actually the grape product with the lowest concentration of OPCs. This is because OPCs are polar molecules which have very low solubility in nonpolar solvents such as oils. However OPCs are available from fresh grapes, grape juice, and red wine.

External links

• "Analysis of Proanthocyanidins in Grape Seed Extracts, Health Foods and Grape Seed Oils", J.Health Sci., 49(1), 45-54, 2003
• Example of an Oligomeric proanthocyanidin in an Isotonic form [1]