Glucosamine and Osteoarthritis
Glucosamine has been widely publicized as an effective treatment for improving joint function, decreasing pain due to osteoarthritis, and slowing down the degeneration of joints due to aging and the wear and tear on joints from their use.
The body produces small amounts of glucosamine from glucose and glutamic acid, but production of endogenous glucosamine may decrease as a person ages (Jackson, 2007). Because glucosamine isn't found in commonly ingested foods, a supplement may be needed to keep levels as high as when you were younger.
How Does Glucosamine Alleviate Joint Pain?
Glucosamine is a substantial component of cartilage. As some people age they develop osteoarthritis. This condition is caused by the breakdown and loss of cartilage in the joints. One or more joints may be affected. The purpose of cartilage is to provide a cushion between the bones of joints so that they don't rub together when you move.
Risk factors for the development of osteoarthritis are getting older, being female, and obesity (Jackson, 2007). The reason that obese people are at greater risk for developing osteoarthritis is because of the increased amount of stress placed on the joints of the body due to increased bodyweight.
Glucosamine supplements are thought to work by slowing the deterioration and even by rebuilding cartilage between the joints. Glucosamine also works by stimulating the production of proteoglycans, which are important building blocks of cartilage, by inhibiting interleukin-1, and by enhancing components of synovial fluid, such as hyaluronic acid (Olsen, 2004). Interleukin-1 is a cytokine released in response to stress and has been shown to cause proteoglycan loss from cartilage in rats (Seed et al. 1993) and the same may occur in humans.
Glucosamine sulfate has been shown to be relatively safe, with few or no side effects. The only reported side effects so far have been gastrointestinal, such as heartburn, nausea, or diarrhea.
Some studies with animals given glucosamine have shown that it may cause a decreased sensitivity to insulin and so glucosamine use by individuals with diabetes may be contraindicated (Jackson, 2007).
Most glucosamine supplements are sold as glucosamine sulfate and the recommended dosage is 1500 mg per day (Jackson, 2007).
There have been numerous research studies conducted to test the effectiveness of glucosamine to alleviate joint pain. In fact, a search on a university library website for glucosamine sulfate returned over 1500 peer reviewed articles. The results of these studies have been mixed, with some studies showing an improvement in joint pain after taking glucosamine sulfate and some studies showing that glucosamine works no better than a placebo. However, all of the studies have shown glucosamine to be relatively safe and numerous studies have also shown that glucosamine may be effective in reducing the symptoms of osteoarthritis. In addition, several studies have even shown that glucosamine supplementation may help to reverse the damage of osteoarthritis by increasing cartilage production. The only real drawback is that glucosamine sulfate supplements do cost money.
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Sports Nutrition: Fats and Proteins, pp. 143-163, Boca Raton, FL: Taylor and Francis Group.
Olson, K.A. (2004). Effects of glucosamine in the treatment of osteoarthritis. Journal of
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Seed, M.P., Ismaiel, S., Cheung, C.Y., Thomson, T.A., Gardner, C.R., Atkins, R.M., and
Elson, C.J. (1993). Inhibition of interleukin 1 beta induced rat and human cartilage
degradation in vitro by the metalloproteinase inhibitor U27391. Annals of the Rheumatic
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