Grape seed extract and rheumatoid arthritis
Grape seed, known as Vitis vinifera and Vitis coignetiae, has become the source of a popular dietary supplement. Grapes were first cultivated near the Caspian Sea, and their use as food and drink had spread throughout the Mediterranean world before the Bible was written. The ancient Greeks believed that wine had wonderful health benefits, and modern science has confirmed that wine has many useful properties. While the benefits of wine may be tarnished by the devastation associated with alcohol abuse, the positive aspects of grape seeds have no such liability. French scientists have published much of the research on grape seed extract, but ironically grape seeds were a distant "second choice." Manufacturers turned to using grape seeds only when peanut skins became unavailable. Most of the high-quality grape seed extract sold in the United States is manufactured by an Italian company called Indena. The oil pressed from grape seeds contains a number of essential fatty acids and is rich in vitamin E compounds. The most interesting constituents of grape seeds are the polyphenols (catechins). These tannin compounds, also called procyanidins, leucoanthocyanins, pycnogenols, or oligomeric proanthocyanidins (OPC), are powerful antioxidants. Commercial extracts are generally standardized for OPC content. Grape leaves and presumably seeds also contain flavonoids, and the skin and seeds are the source of several recently identified compounds known as 5-nucleotidase inhibitors. Grape seed oil can be used for cooking. It has an mild flavor and a high smoking point and is rich in omega-6 fatty acids. Grape seed extract is used in Europe to improve circulation. It prevents oxidation of blood fats and inhibits enzymes that break down the proteins that make up blood vessels. Grape seed is believed to benefit cardiac and cerebral circulation. In animals it reduces capillary permeability and presumably has similar activity in humans. Capillaries may be fragile due to diabetes or other disorders. In four small studies, grape seed extract was better than placebo at improving peripheral circulation as well, resulting in less pain and swelling, fewer nighttime cramps, and less numbness and tingling. Studies have shown that grape seed extract may slow macular degeneration, improve vision stressed by computer screens or glare, and reduce myopia. Although further research is needed, the results have been promising. In test tube research grape seed polyphenols stop the growth of Streptococcus mutans, a bacteria that causes tooth decay. They also slow the conversion of sucrose (table sugar) into glucan, and as a consequence of both these actions, grape seed may have a role in maintaining dental health. Another potential benefit of grape seed extract is anti-inflammatory activity. Grape seeds have tremendous antioxidant activity. Antioxidants soak up and destroy free radicals. Free radicals are what cause much of the damage in inflammatory and degenerative diseases.
Proanthocyanidins (flavonoids) ( grape seed and pine bark extract ) are powerful antioxidants and collagen protectors. In theory, grape seed may increase the risk of bleeding when used with anticoagulants (blood thinners) or antiplatelet drugs. Examples include warfarin (Coumadin), heparin and clopidogrel (Plavix). Some pain relievers may also increase the risk of bleeding if used with grape seed. Examples include aspirin, ibuprofen (Motrin, Advil) and naproxen (Naprosyn, Aleve, Anaprox). Grape seed may interact with prescription drugs, such as angiotensin-converting enzyme inhibitors, methotrexate, allopurinol and cholesterol-lowering drugs. There is evidence that grape seed may interfere with the way the liver breaks down certain drugs. As a result, grape seed may cause the levels of drugs in the body to be too high, leading to serious side effects. If you are taking prescription drugs, ask your health care provider for advice before you take grape seed.
Grape seed extract (GSE) contains Oligomeric proanthocyanidins - also known as OPCs - which are antioxidants that help neutralize unstable oxygen molecules called free radicals. Although the majority of the studies conducted on GSE (and OPCs) have been done in cell culture (test tube) and animals, their ability to reduce free radical damage and oxidative stress suggest that they may be particularly effective in reducing the risk of cancer, cardiovascular disease and a number of the chronic diseases associated with aging. Free oxygen radicals, which are by-products of the normal activity of cells, have been found in excess in RA joints and are believed to contribute to joint damage. As antioxidants like Grape Seed Extract help protect cells against damage from free radicals, a diet that is high in antioxidant rich foods, as well as antioxidant supplements, may be sensible. In theory, grape seed may increase the risk of bleeding when also taken with other products that are believed to increase the risk of bleeding. Examples include Ginkgo biloba and garlic (Allium sativum). In theory, grape seed may excessively lower cholesterol levels in the blood if also taken with herbs and supplements that lower cholesterol levels, such as red yeast. Grape seed may also increase the blood levels of herbs processed by the liver, such as chasteberry (Vitex agnus-castus). There is some evidence that grape seed may enhance the effectiveness of vitamin C and vitamin E.
Usual dose for general health maintenance ranges from 50 to 100 mg daily. To treat illness, doses from 150 to 300 mg per day are recommended. No special precautions have been noted. Animal studies indicate that some of the polyphenols are toxic to the liver; other constituents appear to be hepatoprotective, preventing liver damage due to carbon tetrachloride in mice. There are no data that permit evaluation of these effects in humans. Grape seed extract is fairly high in tannin. It might be prudent not to take this herb at the same time as iron supplements, although no interactions have been documented.
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