Glucosamine
Glucosamine (pronounced glue-KOSE-uh-mean) is made in the body from sugar and is a component of substances called proteoglycans and glycosaminoglycans. These substances are major components or “building blocks” of cartilage. As such, glucosamine is found naturally in the body’s joints and connective tissues, where it’s used for cartilage repair and maintenance. It’s also believed that glucosamine stimulates cartilage cell growth.
Initial research with animals suggested that glucosamine supplements might be useful for people with osteoarthritis, the most common form of arthritis, which results in stiff joints, joint pain, and deformity.
In the early 1980s a small number of studies conducted in Europe and Asia found that some osteoarthritis patients received short-term symptomatic pain relief from taking glucosamine supplements. More recently, a 1992 study of 252 people with osteoarthritis of the knee showed that taking 500 milligrams of glucosamine sulfate three times per day brought significant pain relief compared to a placebo.
Studies comparing the effectiveness of glucosamine to non-steroidal antiinflammatory drugs (NSAIDs) have also been performed. In a four-week study of 199 participants with osteoarthritis in at least one knee, improvements were noted in both those who took 400 milligrams of ibuprofen (an NSAID) three times per day and those who took 500 milligrams of glucosamine sulfate three time per day. Interestingly, the beneficial effects of ibuprofen seemed to level off after the first two weeks of use, while those of glucosamine did not. A similar study was conducted in China, and the results were comparable. What’s more, glucosamine was found to be better tolerated by the participants than ibuprofen, since it didn’t cause as many side effects.
Recent preliminary research also suggests that the supplement might slow down cartilage loss, helping to keep arthritis from getting worse. How? Apparently glucosamine stimulates collagen production and reduces the breakdown of healthy tissue. Additional research is needed to determine if glucosamine supplements actually can reverse the degenerative processes associated with arthritis. However, taking the supplements will not increase the amount of glucosamine in the joints.
Until recently, no long-term studies on glucosamine safety or benefits had been performed. Now, a detailed long-term study of glucosamine (and osteoarthritis of the knee) has been initiated by the National Institutes of Health, but results won’t be available for a couple of years.
Should You Supplement with Glucosamine?
Although glucosamine seems promising for osteoarthritis, not everyone who takes it will experience benefits, and any results at all take at least six to eight weeks to occur. The usual dosage for osteoarthritis is 1,500 milligrams (500 milligrams taken three times a day). If this amount relieves symptoms, the dosage can be gradually decreased.
Glucosamine is available as a “hydrochloride” (HC1) and as a “sulfate.” Both forms have performed equally well in studies. The glucosamine that’s present in supplements is righted from natural sources such as groundrup crab, lobster, or shrimp shells.
Although glucosamine is frequently sold in combination with chondroitin, some researchers suggest it if necessary- to take both, especially since much of the research on chondroitin used an injectable form and not \ form.
No studies have shown that the efficacy of glucosamine is enhanced by taking it with SAMe supplements.
Side effects from glucosamine supplementation include headache, gastrointestinal upset, swelling, and itching, which are reversible when the dosage is decreased or supplements are discontinued. Recently, a preliminary animal study showed that taking supplements are discontinued. Recently, a preliminary animal study showed that taking glucosamine sulfate caused insulin resistance, or decreased insulin action.
source: http://www.nlm.nih.gov/medlineplus/druginfo/natural/807.html
