Glucosamine - Valid Uses and Benefits: A Popular Food Supplement Used for Osteoarthritis and Other Ailments

Glucosamine is a naturally occurring substance in the body. It is found in cartilage, the substance that pads the joints. Glucosamine is also manufactured as a food supplement and can be found in most drug and health food stores. It is one of the most popular dietary supplements sold in the United States with sales estimated at over $810 million in 2005. It is often taken in combination with chondroitin, a substance also found in articular cartilage. It is not known whether taking the combination is better than glucosamine alone.

Osteoarthritis

Osteoarthritis occurs when joint cartilage starts to wear away, causing joint pain. Treatment of osteoarthritis often involves the use of non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin, ibuprofen, naproxen, and many others.

Research in humans such as a study by Reginster, J.Y., et al. published in Lancet in 2001 entitled "Long-Term Effects of Glucosamine Sulfate on Osteoarthritis Progression: A Randomized Placebo-Controlled Clinical Trial" indicates that the use of glucosamine sulfate for mild to moderate osteoarthritis of the knee is beneficial.

Glucosamine can be beneficial in the treatment of osteoarthritis in other joints of the body. Some of the benefits include pain relief and improved joint function. The reason for this may be from an anti-inflammatory effect.

Inflammatory Bowel Disease

In a study done by Salvatore, S., et al. entitled "A Pilot Study of N-acetyl Glucosamine, a Nutritional Substrate for Glucosaminoglycan Synthesis in Paediatric Chronic Inflammatory Bowel Disease" published in Alimentary Pharmacology & Therapeutics in 2000 showed that a form of glucosamine is helpful in the treatment in inflammatory bowel disease (Crohn's disease and ulcerative collitis). More research is needed to make any recommendations.

Rheumatoid Arthritis

A 2007 Japanese study of rheumatoid arthritis patients published in Rheumatology International by Nakamura, H., et al. showed that taking 1500 mg of glucosamine hydrochloride daily significantly improved symptoms according to patient self-evaluation and physician global evaluation. This treatment did not alter measures of inflammation as determined through blood tests.

Medical treatment of rheumatoid arthritis is complicated and requires early intervention and close medical supervision.

Mechanisms of Action

Exactly how glucosamine works is unknown, but the following are some possibilities:

Further Research

Studies such as one done by Thie, N.M., et al. entitled "Evaluation of Glucosamine Sulfate Compared to Ibuprofen for the Treatment of Temporomandibular Joint Osteoarthritis: A Randomized Double Blind Controlled 3 Month Clinical Trial" published in Journal of Rheumatology in 2001 found that glucosamine and ibuprofen (Motrin) are equally effective in reducing symptoms of joint pain.

It has been noted that most of the trials with positive outcomes were funded by manufacturers of glucosamine products while most trials performed by neutral researchers failed to find benefit (Vlad SC, et al. Glucosamine for pain in osteoarthritis: why do trial results differ? Arthritis Rheum. 2007, 56(7): 2267-2277).

A study by Tallarido, R.J., et al. in Journal of Pharmacology and Experimental Therapeutics in 2003 suggests that the addition of glucosamine to non-steroidal anti-inflammatory drugs (NSAIDs) could decrease NSAID use in those patients already taking them.

Adverse Effects

Negative effects of taking glucosamine are generally rare and of a minor nature. There have been no reported significant supplement-drug interactions. There have been no reactions in persons with shell fish allergies (glucosamine is made from the shells of lobster, crab and shrimp). However, persons with this type allergy should use caution while taking this supplement. Caution should also be used in patients with asthma, diabetes, and those on blood thinners.

Dosage

Glucosamine is most commonly supplied in tablets and capsules. The usual dosing is 500 mg three times daily. Most brands are reasonably well standardized, delivering at least 90 percent of the amount of glucosamine or chondroitin promised on the label. Taking this supplement for 60 days is considered a reasonable time frame to determine benefit.

The U. S. Food and Drug Administration does not strictly regulate herbs and supplements. Before taking any herb or supplement you should tell your health care provider to decide whether it is right for you.

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Sep 11, 2008 8:45 PM

Albert Burchsted :

Dennis,

Good balanced article.

My wife and I have been taking glucosamine and chondroitin sulfate for years because of arthritis. We find it is extremely helpful for both of us. The test is when we stop taking it. Within three or four days we begin to notice an increase in symptoms.

You mention that clinical studies are bipolar in their results: Most positive studies come from the glucosamine industry that has vested interest in positive results. You did not state (perhaps you do not know or didn't have the space) what affiliations the naysayers have. They may be affiliated with pharmaceutical houses that provide drugs like Celebrex, Etodolac, Naproxen, Vioxx and the like. If so, they would not want to show that a non-patented, over the counter supplement might provide relief as well as their expensive, heavily advertised drugs do.

This caveat applies to physicians' review groups that appear innocuous on the front, but are loaded with individuals with conflict of interest.

Although not a clinical study, my wife and I are addicted to the feeling we get with glucosamine and chondroitin and would are leery of taking NSAIDS because of the problems that can arise from them,