There exists in nature an amazing bioflavonoid complex, known as Procyanidolic Oligomers (PCO), which possesses incredible antioxidant abilities. There are many sources of PCO bioflavonoids, including grapes, blueberries, cherries, and other fruits. Barks of the lemon tree and Landis pine tree are other known sources. Of all these sources, grape seed extract (GSE) provides the most concentrated form of PCO bioflavonoids. Other terms for these compounds include proanthocyanidin, procyanidin, leucoanthocyanidin, anthocyanidin, Oligomeric Procyanidolic Complexes (OPC), and Pycnogenol®. Pycnogenol® was a term coined by Jaques Masquelier, who patented the extraction process of this bioflavonoid. These patent rights were later licensed to Horphag Research Ltd, a Swiss pharmaceutical company.
Grape Seed Extract Versus Vitamin C and Vitamin E
The antioxidant abilities (i.e., free radical quenching abilities) of grape seed PCOs are twenty times greater than those of vitamin C and fifty times greater than those of vitamin E . Although water soluble, grape seed PCOs can still cross the blood-brain barrier and protect the brain from free radical damage. One of the key factors leading to atherosclerosis (hardening of the arteries) is the oxidation of LDL-cholesterol. Thus, if we can block the oxidation of LDL-cholesterol, we, theoretically, can prevent hardening of the arteries. Vitamin E is a potent inhibitor of the oxidation of LDL-cholesterol . Yet, PCOs found in GSE are fifty times more potent than vitamin E as an antioxidant . PCOs reduce the aggregation of platelets, thereby having a protective role in the prevention of blood clots and strokes .
PCOs and Stoke
PCOs also help in stroke prevention by increasing red blood cell pliability, decreasing blood viscosity and increasing fibrinolytic activity . These properties result in improved blood flow, improved oxygenation to ischemic (low blood flow) areas, and prevention of thromboembolic events. PCOs improve blood vessel wall elasticity and lower blood pressure [3,4]. PCOs help to stabilize the blood-brain barrier . By combating atherosclerosis and hypertension, PCOs provide additional protection against stroke. Grape seed proanthocyanidins confer more protection against lipid peroxidation that do vitamin C, vitamin E or beta-carotene [6,7].
Grape Juice or Wine?
Wine consumption confers a protective effect against heart disease . In February 1995, a study published in the medical journal, Circulation, revealed that six glasses of grape juice were as effective as two glasses of wine in the prevention of heart disease. The PCO concentration in wine is substantially greater than that in grape juice. This is convincing evidence that the cardiovascular protective effects of wine are provided by grape seed PCOs.
Other Benefits of Proanthocyanidins
For the last fifty years, proanthocyanidins have been used in France for the treatment of blood vessel disorders. PCOs are effective in the treatment of bruises, varicose veins and spider veins . Proanthocyanidins are not only potent anti-histaminic, anti-allergic, and anti-ulcer actions but are also potent anti-inflammatory agents. The process of inflammation is intimately linked to both atherosclerosis and stroke. .
See the discussion of curcumin for a more detailed explanation of this relationship.
Proanthocyanidins potentiate the activities of other antioxidants, such as vitamins C and E. Antioxidants reduce the incidence of
all types of cancer. By ingesting PCOs, Russian cosmonauts make use of PCOs as a prophylactic treatment for radiation exposure. Radiation exposure from the sun can cause free radical damage to the lens and retina of the eye. Cataracts are formed from thickened, oxidized proteins in the lens. Vitamins C and E can significantly minimize the development of cataracts [10,11]. As mentioned earlier, PCOs have antioxidant abilities that are 20 times greater than those of vitamin C and 50 times greater than those of vitamin E . PCOs have been highly effective against tooth decay and gum disease due to their high affinities for connective tissue . Both of these disease processes are initiated by inflammation caused by free radicals in food. Periodontitis has also been determined to be an independent risk factor for stroke and heart disease. The antioxidant abilities of PCOs protect the skin from ultraviolet radiation damage . They have also been effective in reducing the allergic reaction in bronchial tubes in asthma patients and effective in reducing inflammation of the alveoli in emphysema sufferers .
Study Shows Grape Seed Extract Prevents Beta Amyloid Accumulation
More recent research (The Journal of Neuroscience, 2008) has demonstrated grape seed extract prevents beta amyloid accumulation in the brain cells of a mouse model for Alzheimer’s disease, suggesting that it may block the formation of plaques. The accumulation of beta amyloid protein in Alzheimer’s disease form toxic plaques that disrupt normal brain function. In fact, grape seed extract not only reduced beta amyloid accumulation and plaque formation in brains of Alzheimer’s mice but also reduced cognitive decline. Gary Arendash, PhD, of The Byrd Alzheimer’s Institute, an expert not affiliated with the study stated “The potential of natural compounds to provide real health benefits to brain function is only now beginning to be realized by brain researchers. The lesson they may eventually learn is that sometimes you just can’t improve upon Mother nature.”
The major active components in this study’s grape seed extract product are catechin and epicatechin, which are also abundant in tea and cocoa.
See the discussion on Green Tea for more details
These components differ from resveratrol, a polyphenol that has also been decribed to reduce beta amyloid. However, resveratrol seems to be effective only at extremely high doses, which may limit its use in people. Unlike resveratrol, the catechins in grape seed extract appear to be effective at much lower doses.
In summary, Grape seed extract PCOs serve as neuroprotective agents in the prevention of stroke, not only because they protect blood vessels but also because they are among the few dietary antioxidants that readily cross the blood-brain barrier. Their hemodynamic, free radical scavenging, and cholesterol-lowering abilities help protect against stroke. They maintain blood vessel health, enhance blood supply to the brain, and reduce the viscosity of blood, which has been implicated as a causative factor for stroke. They further prevent vascular injury by strengthening blood vessel walls. This is of particular importance to diabetics since they are especially prone to vascular fragility. By readily traversing the blood-brain barrier, they are able to prevent injuries related to oxidative stress from free radicals and aid in recovery from free radical damage. By preventing beta amyloid accumulation in the brain cells, they may also prevent the formation of toxic plaques that disrupt normal brain function in Alzheimer’s disease.
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- Jialal I, Grundy SM. Effect of combined supplementation with Alpha-tocopherol Ascorbate and Beta-carotene on Low-density Lipoprotein Oxidation. Circulation 88: 2780-2786,1993.
- Passwater RA. The New Superantioxidant-Plus. New Cannan: Keats Publishing Inc., 1992.
- Frankel EN, et al. Inhibition of oxidation of human low-density lipoprotein by phenolic substances in red wine. Lancet 341:454-457, 1993.
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- Bagchi D, et al. Protective effects of grape seed proanthocyanidins and selected antioxidants against TPA-induced hepatic and brain lipid peroxidation and DNA fragmentation, and peritoneal macrophage activation in mice. Gen Pharmacol 30(5):771-6, 1998.
- Bagchi D, et al. Oxygen free radical scavenging abilities of vitamins C and E, and a grape seed extract proanthocyanidins in vitro. Res Commun Mol Path Pharmacol 95(2):179-89,1997.
- Dartenuc JY, et al. Capillary resistance in the geriatric. Study of a microangioprotector (Endotelon:95% PCO derived from grape seeds). Bordeaux Med 13:903,1980.
- Hansen C. Grape Seed Extract. New York: Healing Wisdom Publications, 1995.
- Atkinson, D. Malnutrition as an etiological factor in senile cataract. Eye, Ear Nose and Throat Monthly 31:79-83,1952.
- Bravetti G. Preventive medical treatment of senile cataract with vitamin E and anthocyanosides: Ann Opthalmol Clin Ocul 15:109,1989.
- Uchida S, et al. Condensed tannins scavenge active oxygen radicals. Med Sci Res 15:831-2,1980.