Background information
Grape seed extract is a potent source of proanthocyanidins, a naturally occurring powerful antioxidant. Proanthocyanidins, or PCO (a highly specialized group of bioflavonoids), have been extensively studied since the late 1960s for their powerful vascular wall strengthening properties and free radical scavenging activity. Proanthocyanidins are also present in red wine, and the bark of the maritime pine.

History and folk use
In 1834, French explorer Cartier was trapped by ice during an expedition to the Saint Lawrence river. Forced to survive on limited food, he began to develop scurvy, a severe deficiency in vitamin C. Fortunately, he managed to survive by taking tea made from the bark and needles of pine tree, as told by a native American. The methods of extracting PCO from pine bark and grape seed were patented in 1951 and 1970 respectively, by Masquelier (Murray, 1995). 
 
Parts used and Key uses
Seed is used. Key uses:

• Antioxidant supplementation
• Circulatory problems
• Atherosclerosis prevention
• Capillary fragility and easy bruising
• Varicose veins
• Poor vision and eye problem
• Degenerative disease (e.g. Cancer)
• Wound healing 

Popularity
Grape seed extract has been preferred over the extract from pine bark based on the research done between 1951 and 1971, as well as intensive research from 1972 to 1978 (Murray, 1995). For instance, Dr Masquelier discovered that the strongest antioxidant component contained in grape seed PCO-gallic esters is missing from the PCO of pine bark (Masquelier, 1993). In France, the sale of grape seed extract is roughly 400 times greater than that of pine bark (Murray, 1995).
 
Active constituents
Procyanidolic oligomers (pcos) (also called oligomeric procyanidins, or OPC) 
 
Recommended use
According to PDR for Herbal Medicines (2000), grape seed extract has been used for preventive therapy with 50mg daily. For the purpose of treatment, 150-600 mg can be taken in divided doses daily. 
 
How it works
There are three major properties of grape seed extract that contribute to its beneficial role in a variety of health conditions, including:

(1) Antioxidant: Free radicals are unstable molecules that destroy tissues by oxidising the lipids (that compose cell membranes) and damaging DNA (the body's genetic material) (mccaleb, 2000). Free radicals have been linked to many health problems, including premature ageing, heart disease, arthritis, gastrointestinal disease, and even cancer. Research has shown that pcos are very effective antioxidants - 50 times more potent than vitamin E and up to 20 times more powerful than vitamin C. Pcos can neutralize free radicals before they can cause damage to the body. It was also found that pcos can chelate to free iron molecules, thereby preventing iron-induced lipid oxidation (Murray, 1995). From a cellular perspective, one of pcos' most advantageous features is that they are incorporated within the cell membrane. Coupled with such physical characteristics, the ability to protect against both water and fat-soluble free radicals provide incredible protection to the cells against free radicals.

(2) Supporting collagen structures and preventing collagen destruction: Collagen, the most abundant protein in the body, is responsible for maintaining the structural integrity of the skin, blood vessels, tendons, ligaments, cartilage, and connective tissue. Pcos reinforce collagen by binding and cross-linking to collagen fibers. They also inhibit the damaging effects of enzymes (e.g. Hyaluronidase, elastase and collagenase, which are commonly released during inflammation) that can degrade connective tissues structures.

(3) Prevention of inflammation and allergies: Masquelier (1993) showed that pcos can prevent the release and synthesis of compounds that promote inflammation and allergies, such as histamine, serine proteases, prostaglandins, and leukotrienes.

Health applications of Grape Seed Extract
With the powerful functional properties described above, the beneficial effects of grape seed extract encompass a wide range of health applications, especially in the areas of protection against serious diseases, oxidative damage and ageing. For instance:

(1) Cardiovascular disease: Studies show that oxidation of LDL cholesterol by free radical is a key factor leading to hardening of arteries and heart disease (Gruenwald et al, 2000). Pcos protect the body against such undesirable effects with their potent antioxidant properties. Meanwhile, it was shown that grape seed extract is able to prevent the stickiness of blood platelets that can lead to blood clots and strokes. In addition, pcos have been shown, in animal studies, to lower blood cholesterol and shrink the size of the cholesterol deposit in arteries (Wegrowski et al, 1984).

(2) Cancer prevention: Chemoprotective properties of PCO include activity against free radicals and oxidative stress. The anti-tumour-promoting activity due to strong antioxidant effects of pcos has been demonstrated in animal models (Gruenwald et al, 2000). Although not a cure for cancer, using pcos is certainly helpful in cancer prevention.

(3) Eyes: In studies on vision-related problems, grape seed extract demonstrated an ability to fortify the collagen that makes up the capillaries. It also increased microcirculation to the retina of the eye (Lagrue, 1981).

(4) Nervous system: pcos have the ability to cross the blood-brain barrier, where it may protect the brain from oxidation.

(5) Skin care: Since pcos can stabilize collagen and elastin, they help improve the elasticity and youthfulness of the skin.

(6) Teeth and gum health: Through their anti-inflammatory effects, free radical deactivation, and connective tissue protection, pcos provide healing and preventive benefits to teeth and gums.

Safety
Grape seed extract is considered non-toxic and has been extremely well tolerated in clinical trials (mccaleb, 2000). According to Natural Medicine Comprehensive Database (2000), no interactions are known to occur, and there is no known reason to expect a clinically significant interaction with grape seed, in terms of drug interaction and contraindications. For safety concerns over the period of pregnancy and lactation, there is insufficient reliable information available and it is best to avoid amounts greater than those found in food.

Note: Information provided is based on thorough research done on scientific and reliable sources. However, it is not meant to substitute for the advice provided by your own physician or other medical professional.

 
REFERENCES
1. Gruenwald, J. Et al. (2000). PDR for Herbal Medicines. Medical Economics Company. USA. 2. Lagrue, G., Oliver-Martin F, Grillot A. A study of the effects of procyanidol oligomers on capilary resistance in hypertension and in certain nephropathies. Semaine des Hoitaux de Paris 1981; 57 (33-36): 1399-1401. 3. Masquelier, J. And Schwitters B.: OPC in Practice: Biflavanols and Their application. Alfa Omega, Rome, 1993. 4. Mccaleb, R.S., Leigh, E., & Morien, K. (2000). The Encylopedia of Popular Herbs. Prima Health. USA. 5. Murray, M.T. (1995). The Healing Power of Herb. Prima Health. USA. 6. Natural Medicines Comprehensive Database. (2000). Therapeutic Research Faculty. USA. 7. Wegrowski J, Robert AM, and Moczar M: The effect of procyanidolic oligomers on the composition of normal and hypercholesterollemic rabbit aortas. Biochem Pharmacol 33, 3491-3497, 1984.