Grape Seed Extract

Botanical Name(s):

Vitis vinifera

Other Name(s):

oligomeric proanthocyanidins, OPC, pycnogenol

General Description:

The grape has a long history of medicinal uses. Ancient Egyptians treated asthma with grapes. More recently, sap from grape branches was used to treat skin irritations and scrapes.

Modern medicine may have discovered measurable benefits from compounds in both grape seeds and red wines. Studies of the "French paradox" explain these benefits. The typical French diet contains high levels of saturated fat, yet French people have less heart disease than their American counterparts. The difference appears to be the red wine that the French drink. Further research suggests that the protective ingredients in wine are resveratrol and certain tannins. Proanthocyanidin, a tannin-like phenolic compound found in the seed of grapes, appears to have a protective activity similar to red wine.

Grape seed extract is a material made from the crushed seeds of grape plants. It contains primarily proanthocyanidin, a phenolic chemical belonging in the larger group of plant phytochemicals called flavonoids, and the more closely related subgroup of tannins. Proanthocyanidin is thought to produce a protective effect on blood vessels and the cardiovascular system by inhibiting the breakdown of collagen , thus reducing the likelihood of a heart attack and stroke. In addition, it may have an antioxidant effect that is thought to decrease the risk for developing certain cancers.

Medically Valid Uses:

Currently, there are no documented valid medical uses for grape seed extract.

Unsubstantiated Claims:

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Grape seed extract is claimed to reduce the risk for heart attack.

The tannins, which in grape seed extract include proanthocyanidins and oligomeric proanthocyanidins, have been shown to be active antioxidants and antimutagenics. Because of these properties, the constituents of grape seed extract are thought to protect the lining of blood vessels and other tissues from damage from free radicals, oxidized LDLs, and other harmful components of metabolism.

Grape seed extract is claimed to reduce the production of histamine, and thus possibly decreasing the severity of nasal allergies, to reduce the premature destruction of vitamin C and to act as a smooth muscle relaxant in blood vessels.

Dosing Format:

Grape seed extract is generally available in capsule form. Follow packaging instructions for the correct dose.

Grape seed oil, an aromatic oil used for salad dressings, contains little proanthocyanidin.

Side Effects, Toxicity and Interactions:

There are no known side effects or significant food or drug interactions associated with grape seed extract.

Additional Information:

Click here for a list of reputable Web sites with general information on nutrition.

References:

1. King A, Young G. Characteristics and occurrence of phenolic phytochemicals. J Am Diet Assoc. 1999;99(2):213-8.

2. Feldman KS, Sahasrabudhe K, Smith RS, Scheuchenzuber WJ. Immunostimulation by plant polyphenols: a relationship between tumor necrosis factor-alpha production and tannin structure. Bioorg Med Chem Lett. 1999;9(7):985-90.

3. Sakagami H, Oi T, Satoh K. Prevention of oral diseases by polyphenols (review). In Vivo. 1999;13(2):155-71.

4. Hatano T, Yasuhara T, Yoshihara R, Agata I, Noro T, Okuda T. Effects of interaction of tannins with co-existing substances. VII. Inhibitory effects of tannins and related polyphenols on xanthine oxidase. Chem Pharm Bull. 1990;38(5):1224-9.

5. Dauer A, Metzner P, Schimmer O. Proanthocyanidins from the bark of Hamamelis virginiana exhibit antimutagenic properties against nitroaromatic compounds. Planta Med. 1998;64(4):324-7.

6. Plumb GW, De Pascual-Teresa S, Santos-Buelga C, Cheynier V, Williamson G. Antioxidant properties of catechins and proanthocyanidins: effect of polymerisation, galloylation and glycosylation. Free Radic Res. 1998;29(4):351-8.

7. Fremont L, Belguendouz L, Delpal S. Antioxidant activity of resveratrol and alcohol-free wine polyphenols related to LDL oxidation and polyunsaturated fatty acids. Life Sci. 1999;64(26):2511-21.