The Beneficial Effects of Glucosamine and Chondroitin Sulfate
By Lee A. Mancini, MD, CSCS, CSN
As the average age and average weight of Americans increases, more and more people will experience knee pain and osteoarthritis. Vioxx, a Cox-2 inhibitor, was pulled by the FDA from the market due to life-threatening side effects. Many other prescription pain medications meant to alleviate osteoarthritis pain have also come under closer scrutiny, like Celebrex, Bextra, and Naprosyn. Now people are looking for alternative methods for to control their chronic joint pain. In this article we will take a closer look at glucosamine and chondroitin sulfate, two supplements that may help improve chronic knee pain and osteoarthritis.
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Glucosamine is an aminomonosaccharid found in human tissues, including cartilage. The word aminomonosaccharid simply means that one amino acid (aminomono-) is attached to a sugar (saccharid). In this case Glucosamine is formed by adding an amino group to glucose. It is the primary building block of proteoglycans and causes increased production of hyaluronic acid. Chondroitin sulfate is a mixed group of glycosaminoglycans found in articular cartilage. They are two major compounds found in healthy articular cartilage (1). Many people wonder how eating two proteins would affect the cartilage inside your knee joint. Carbon-14 tagging of ingested glucosamine revealed that four hours after ingestion there is increased proteoglycan synthesis and increased human chondrocyte gene expression in vitro (2).
Proven Performance Effects
There have been more studies examining the effects of glucosamine supplementation alone or in combination with chondroitin sulfate, than examining chondroitin sulfate by itself. There have been nearly 37 double-blinded trials showing that glucosamine and chondroitin sulfate supplementation produces symptomatic relief from osteoarthritis (3). Supplementing with 1500 mg of glucosamine per day over a three-year period showed statistically significant relief of the symptoms of osteoarthritis and a significant decrease in the progression of knee osteoarthritis (4). Another study showed that 1500mg of glucosamine per day over three years improved symptoms of osteoarthritis and also had no joint space narrowing; whereas, the placebo group experienced a worsening of symptoms and 0.31 mm of mean joint space narrowing (3). None of the placebo groups in the studies improved over time. The glucosamine and chondroitin sulfate groups showed improvement even at two weeks, having an increase in function and a decrease in articular stiffness (5). In examining the progression of osteoarthritis, supplementation of 400 mg of chondroitin sulfate three times a day (a total of 1200 mg daily) had only an 8.8% increase of new erosive osteoarthritis compared with a 29.4% increase of new lesions in the placebo group over a three-year period (6).
Adverse Effects
The safety of glucosamine and chondroitin sulfate is excellent. In all of the studies done on glucosamine and chondroitin sulfate, there were no serious side effects, and the placebo groups had the same incidence of side effects as the treatment groups. To date there have been no reports of glucosamine and chondroitin sulfate interfering with any prescription medications as well.
Summary
There is clear evidence that glucosamine alone, glucosamine in combination with chondroitin sulfate, and chondroitin sulfate alone provide symptomatic relief of osteoarthritis. Some evidence also exists showing that chondroitin sulfate and glucosamine slow the progression of osteoarthritis and improve joint function. Glucosamine and chondroitin sulfate are safe, effective supplements. Both are deemed legal by all of the governing bodies in sports. If you are going to try both of these supplements you need to take them for at least three months to truly determine if they are making a difference for you. You should take a supplement that contains 1500 mg glucosamine and 1200 mg chondroitin sulfate.
For more information on other supplements and sports performance enhancers check out the Doctor of Fitness Guide To Supplements.
Send any questions or ideas for topics of future interest to questions@DoctorOfFitness.com.
Note: Lee A. Mancini graduated from Harvard as a two-sport athlete with honors in biology. Board certified in sports medicine and family practice, he works at the Family Health Center and UMass Sports Medicine Center in Worcester . He trains select clients as a certified strength and conditioning specialist and sports nutritionist. If you are interested in hiring him to design an individualized program, click here for our paid consultation services.
References
1. Schwenk, T.L., & Costley, C.D. (2002). When food becomes a drug: Nonanabolic nutritional supplement use in athletes. The American Journal of Sports Medicine, 30, pp. 907-916.
2. Antonio, J. & Stout, J.R. (2001). Sports supplements. Philadelphia: Lippincott Williams & Wilkins.
3. Walker-Bone, K. (2003). “Natural remedies” in the treatment of osteoarthritis. Drugs and Aging, 20(7), pp. 517-526.
4. Reginster, J.Y., Deroisy, R., Paul, I. (1999). Glucosamine sulfate significantly reduces progression of knee osteoarthritis over 3 years: A large, randomised, placebo-controlled, double-blind, prospective trial. Arthritis Rheumatology, 42(9S), S400.
5. Richy, F., Bruyere, O., Ethgen, O., Cucherat, M., Henrotin, Y., & Reginster, J. (2003, July). Structural and symptomatic efficacy of glucosamine and chondroitin in knee osteoarthritis. Archives of Internal Medicine, 163(13), pp. 1514-1522.
. Verbruggen, G., Goemaere, S., Veys, E.M. (1998). Chondroitin sulftate: Structure/disease modifying anti-arthritis drug in the treatment of finger joint osteoarthritis. Osteoarthritis Cartilage, 6(A), pp. S37-S38.
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