The Introduction of Pine bark extract |
发布时间:2012-05-25 信息来源:admin 发布人:admin 点击次数:2271 |
Pine bark extract Description Pine bark extract is made from the bark of the maritime pine tree (Pinus pinaster), which contains naturally occurring chemicals called proanthocyanidins. The maritime pine is native to the western Mediterranean, with a range extending over Portugal, Spain, France, Italy, and Morocco. Pine bark extract is commonly sold under the brand name Pycnogenol. Pycnogenol is also the name of a group of compounds that contain proanthocyanidins taken from a number of natural sources, such as grape seeds (see Grapes) and other plants. In addition to the Pycnogenol brand, there are several other pine bark extract supplements available, which may use different types of pine bark and have different formulations. Pine bark extract is used for its antioxidant properties. OverviewAlthough interest in pine bark extract is growing among medical researchers, only limited data from clinical trials supports the claims made about its benefits for health. A few small early studies in humans have shown possible benefits in reducing swelling from a circulation disorder called chronic venous insufficiency. Some early studies have suggested it may help lower blood sugar in some diabetic patients. Laboratory studies have indicated pine bark extract may have some antioxidant properties. How is it promoted for use?Proponents claim that pine bark extract is a powerful antioxidant. Antioxidants are compounds that block the action of free radicals, activated oxygen molecules that can damage cells. Supporters believe pine bark extract protects against arthritis, complications from diabetes, cancer, heart disease, and problems with circulation such as swelling and varicose veins. Other reported benefits include improved memory, fewer effects from stress, better joint flexibility, and decreased inflammation. Some claim that pine bark extract supplements are much more effective in eliminating free radicals than vitamins C and E. What does it involve?Pine bark extract is available as a tablet and capsule in a range of strengths. Practitioners may recommend a dose ranging from 25to 300 milligrams per day for up to 3 weeks. After that, some suggest a maintenance dose of 50 to 100 milligrams per day, while others recommend continuing a "saturation dose" of 20 to 30 milligrams per 20 pounds of body weight. Others recommend doses of 600 milligrams or more per day, depending on the reason for taking it. What is the history behind it?In the winter of 1535, a French explorer named Jacques Cartier found his ship ice-bound in the St. Lawrence River, in what is now Quebec. Having no fruits or vegetables, the crew became ill with scurvy, a disease resulting from vitamin C deficiency. Several had already died when a Native American told them how to prepare a tea made from tree bark. Many crew members recovered and attributed miraculous qualities to the tea. It is thought now that the tea was prepared from the bark of the Eastern White Cedar tree and that it contained large amounts of vitamin C. In 1951, French researcher Dr. Jacques Masquelier reportedly read this account in Cartier’s writings and began a search for the active ingredients in the tea. He was able to extract proanthocyanidins from the bark of the European coastal pine tree. He patented the process and named the compound Pycnogenol. In 1970, proanthocyanidins were also extracted from grape seeds. The compound found in grape seeds and plants is referred to as either proanthocyanidins or pycnogenol. However, it differs somewhat from the pycnogenol extracted by Dr. Masquelier. What is the evidence?There are not enough data from clinical trials to support most of the health claims made for any form of pine bark extract, although interest in proanthocyanidins among medical researchers is growing. There are reports from small human studies that pine bark extract may be helpful in treating circulation disorders. One clinical trial began in August 2003 to find out whether pycnogenol helps reduce lymphedema (swelling from fluid buildup, which can occur after procedures in which lymph nodes are affected) after treatment for breast cancer. This study was still recruiting patients as of early 2007. A small human study found that a single high dose of pine bark extract in the form of a bioflavonoid mixture was effective in reducing platelet clumping in smokers for more than three days, which would be expected to reduce blood clotting. This may mean that pine bark extract could lower risk for stroke or heart attack, but clinical studies to find out whether this is true have not been done. Some small brief studies have been done to look at pine bark extract’s possible usefulness in treating asthma, menstrual pain, blood clots and leg swelling during long airplane flights, retinal disease in diabetics, high cholesterol, and other disorders. All of these studies need to be done on larger groups of people under carefully controlled conditions to find out whether pine bark extract actually helps any of these problems. Studies also suggest pine bark extract has antioxidant properties, which are sometimes helpful in reducing cancer risk. Further research is needed to find out whether pine bark extract may have any benefit for preventing or treating cancer. Are there any possible problems or complications?This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must provide the FDA with results of detailed testing showing their product is safe and effective before the drug is approved for sale), the companies that make supplements do not have to show evidence of safety or health benefits to the FDA before selling their products. Supplement products without any reliable scientific evidence of health benefits may still be sold as long as the companies selling them do not claim the supplements can prevent, treat, or cure any specific disease. Some such products may not contain the amount of the herb or substance that is written on the label, and some may include other substances (contaminants). Though the FDA has written new rules to improve the quality of manufacturing processes for dietary supplements and the accurate listing of supplement ingredients, these rules do not take full effect until 2010. And, the new rules do not address the safety of supplement ingredients or their effects on health when proper manufacturing techniques are used. Pine bark extract has been reported to be safe. Some people report mild problems such as headache, nausea, and upset stomach. Not much is known about possible interactions with other drugs and herbs. Always tell your doctor and pharmacist about any herbs or supplements you are taking. Allergic reactions to pine are possible, although reactions to pine bark extract have not been reported in the available medical literature. Pine bark extract has not been studied in pregnant or breast-feeding women. Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences. |