Glucosamine is a naturally occurring substance that is so well-known as a supplement, many people may not be aware it is actually made by the body. It’s thought that as people age, the ability to produce glucosamine in the body declines. This is a problem because glucosamine forms the building blocks for cartilage, tendons and the cushioning fluid in joints. If glucosamine production in the body doesn’t keep up with daily wear and tear, joints can begin to suffer.
Glucosamine is required to produce proteoglycans, the building blocks for healthy joint tissue. Amazingly, glucosamine also stimulates the production and reduces the breakdown of these important molecules. Further, it’s thought that glucosamine plays a role in stimulating the production of hyaluronic acid, which lubricates joints and increases their shock-absorbing capabilities. All these functions make glucosamine a highly important nutrient for healthy joints.
Studies have also indicated that glucosamine can reduce inflammation. As ongoing inflammation can be responsible for progressive joint damage, this anti-inflammatory action of glucosamine is another contributor to its joint-protective capabilities.
With all these joint-protective actions, osteoarthritis is an area where glucosamine appears to excel. There’s very strong scientific evidence supporting the use and safety of glucosamine in osteoarthritis and many studies have demonstrated that glucosamine supplementation reduces pain and increases joint function in sufferers of this condition.
One three-year study also managed to show that glucosamine slowed disease progression, which would suggest that starting on it sooner rather than later is a very good idea. Interestingly, several studies have found glucosamine to be as effective as non-steroidal anti-inflammatory drugs (NSAIDs) in giving symptomatic relief without the side-effects often associated with these drugs.
Glucosamine is not typically used for rheumatoid arthritis because the cause and progression of this disease are entirely different from osteoarthritis. Yet a study published in 2006 indicated a marked improvement in symptoms of patients with rheumatoid arthritis after taking glucosamine, even though blood tests tracking the disease progression remaining unchanged.
Beyond the joint benefits of glucosamine, research indicates glucosamine may have anti-HIV activity with one study suggesting a “significant” anti-HIV effect. Animal studies have indicated glucosamine may also improve graft survival as well as reduce central nervous system inflammation and nerve damage associated with multiple sclerosis. More research needs to be done in all these areas.
Glucose debate
Studies in rats in the early 1990s suggested glucosamine supplementation may have a negative effect on glucose metabolism and insulin secretion. This began an ongoing debate about the possible translation of this effect to humans. Matters were not clarified by conflicting human studies.
This lack of clarity is a problem compounded by the fact that people with obesity and diabetes are more likely to suffer from osteoarthritis. What should we do while the jury appears to be out? For those people who enjoy the benefits glucosamine brings their joints, regular testing of blood sugar, fasting insulin and cholesterol levels should be maintained.
How to take it
Glucosamine is available in a confusing array of varieties over the counter. Commercially prepared glucosamine comes in three forms: glucosamine sulfate, glucosamine hydrochloride and N-acetyl-glucosamine (NAG). These forms all work slightly differently in the body and there are differing opinions about which is better. Not all clinical studies of glucosamine have produced positive results, but it’s generally thought that glucosamine sulfate has the most evidence behind it.
While glucosamine may be comparable to NSAID therapy, it is slower in its onset and may take 2–3 weeks before the benefits are felt. Individuals should try glucosamine therapy for 2–3 months to determine their own response, with a recommended daily dose of about 1500mg a day.
Side-effects from glucosamine are very rare and many studies, including one lasting three years, indicate it is a very gentle and safe therapy. People with a shellfish allergy need to be careful as most forms are derived from shellfish. There are vegetarian alternatives on the market, but they’re a little harder to come by.
If you currently take any medication, you should speak to your doctor before starting glucosamine and, due to a lack of safety data, glucosamine should not be taken during pregnancy.
Kate Mirow is a naturopath practising at Your Health in Manly, NSW, an integrative medical centre. Kate uses herbs, homoeopathy and nutritional supplements as well as dietary and lifestyle advice to assist her patients back to health. E: kmirow@yourhealth.com.au, T: 02 9977 7888.
