Grape Seed Extract

Vitis viniferea, V.  coignetiae    Vitaceae.  The common name of grape seed extract.

Attention was drawn to grape extracts by the so called “French Paradox.”  There is nearly a 40% lower risk of coronary heart disease among wine drinking French, than for other drinkers around the world who do not drink wine.  The reasons, it was discovered, have to do with antioxidant oligomeric proanthocyanidins (OPC) present in wine from the grapes.  The seeds, a byproduct of the wine industry, have become an important source of  OPCs.  Other sources of OPCs are the skins of peanuts and pine bark.^[i]

The seed extract is commonly available in capsule form.  It is sometimes bound with phosphatidylcholine, referred to as the “phytosome process, “ which is considered to be more effective^[ii].  A similar product is

Pycnogenol,  pine bark extract.

Methyl extract of grape contains epsilon-viniferin, oligostilbenes, ampelopsins A, C, F and the mixture of vitisin A and cis-vitisin A. The polyphenolic compounds of 5-neucleotidase inhibitors designated as NPF-88BU-1A and NPF-88BU-1B have also been isolated from the seeds and skins.^[iii]  There are also tannins and proanthocyanidins.  The polyphenolic bioflavonoids, proanthocyanidins, which are present in many fruits, vegetables, nuts, barks, seeds and flowers, are considered to be the most chemically active.

Proanthocyanidins are shown to have a wide variety of effects, including antibacterial, antiviral, anti-inflammatory, antiallergic and vasodilatory action.  They inhibit lipid peroxidation, platelet aggregation, capillary permeability and fragility as well as modulate activity of certain enzyme systems.^[iv]  They also inhibit the destruction of collagen.  They have potent antioxidant and free radical scavenging effects.

They have been show to be effective for some microvascular injuries and circulatory disorders which include pain, limb heaviness and feelings of swelling.

Grape seed extract and pine bark extract, based on their antioxidant activity, have been subject to exaggerated and even false claims of their ability to cure almost anything.  They are, however, used as popular nutritional supplements and antioxidants by the public.  The primary uses are in the treatment of venous and capillary disorders, including venous insufficiency, varicose veins, capillary fragility and retina disorders like diabetic retinopathy and macular degeneration.^[v]

As a daily nutritional support, 50 mg. daily is recommended.  Therapeutic dosage should be increased to 150 to 300 mg.  For the proanthocyanidins bound to phosphatidylcholine, the dosage for nutritional support is 50 mg., for therapeutic use, 150 mg.^[vi]

No adverse reactions in humans have been reported, there has been hepatotoxicity in mice.^[vii]