In the U.S., arthritis has become a prevalent chronic health concern and one of the most common causes of disability, claims the Arthritis Foundation. Osteoarthritis is the most common form, affecting about 27 million people in the U.S. The American Academy of Orthopaedic Surgeons notes there were about 800,000 hip and knee replacement surgeries in 2003 primarily because of arthritic destruction. Medications such as anti-inflammatories are often used for arthritic symptoms, but glucosamine and chondroitin are natural supplements used for osteoarthritis because of the positive physical effects they can cause.
Glusoamine Defined
Glucosamine is a natural substance found within the joint capsules of animals and the shells of shellfish. In humans, glucosamine is produced by chondrocyte cells within joints and used to synthesize glycosaminoglycans and proteoglycans. These by-products of glucosamine combine with collagen to form and maintain healthy cartilage. Glucosamine and its by-products also maintain joint fluid viscosity, which allows for normal lubrication and cushioning, especially in weight-bearing joints. Glucosamine sulfate is the most common supplemental form of glucosamineand is usually made from processing the exoskeletons of shellfish.
Chondroitin Defined
Chondroitin is a natural substance in cartilage, which acts as a shock absorber within synovial joint capsules. Chondroitin has the ability to absorb water, which allows cartilage to maintain its pliable and spongy properties. Chondroitin may also disable enzymes that break-down cartilage. The supplemental form of chondroitin is chondroitin sulfate, which is commonly made from processing the tracheas and other cartilagenous material from domestic animals, such as cattle. Chondroitin is often combined with glucosamine in a variety of products that include tablets, capsules and liquids.
Physical Effects on Knee Osteoarthritis
There are a number of quality clinical studies on humans that demonstrate glucosamine sulfate is effective as a treatment for mild to moderate knee osteoarthritis. PubMed cites a 2002 long-term study from the Czech Republic that concluded glucosamine sulfate retarded progression of knee osteoarthritis, reduced pain and increased flexibility.
Physical Effects on Arthritic Pain
Glucosamine sulfate with and without chondroitin sulfate has demonstrated the ability to relieve arthritic pain. A quality example is noted again by PubMed, which cites a 2007 study reported in "Arthritis Rheumatology" that concluded glucosamine sulfate is more effective than acetaminophen in treating the symptoms of knee osteoarthritis. This study, along with most that show positive physical effects, used 1,500mg of glucosamine sulfate daily.
Physical Effects of Chondroitin on Knee & Hip Pain
Although chondroitin is often combined with glucosamine in supplements and in clinical studies, it has shown beneficial physical effects by itself. The University of Maryland Medical Center has concluded that several scientific studies suggest that chondroitin sulfate may be effective for symptomatic relief of knee and hip osteoarthritis but not necessarily for cartilage repair or new growth. The typical dosage of chondroitin sulfate in clinical trials is 1,200 mg daily.
Glucosamine & Chondroitin Combined
A large, multi-center trial in the U.S. begun in 1998, called GAIT, tested whether glucosamine and chondroitin used separately or in combination reduced pain in participants with knee osteoarthritis. The results were that both glucosamine and chondroitin showed positive results separately, as did the glucosamine/chondroitin combo, but the combination did not show additional "synergistic" benefits. It was noted in this large trial that significant clinical changes from glucosamine and chondroitin can take up to three months to be noted.
Negative Effects of Glucosamine & Chondroitin
Glucosamine and chondroitin sulfates have not caused any serious side effects within any documented clinical studies. Mild side effects that have been reported include heartburn, abdominal pain, nausea and headache. Glucosamine sulfate can cause a potentially serious allergic reaction in those who are allergic to shellfish. Some glucosamine products are now derived from vegetable sources and don't carry this risk.
References
- Arthritis Foundation: Arthritis Statistics
- American Association of Hip and Knee Surgeons: American Academy of Orthopaedic Surgeons Statistics
- PubMed: "Glucosamine sulfate use and delay of progression of knee osteoarthritis: a 3-year, randomized, placebo-controlled, double-blind study"; Arch Intern Med; Oct, 2002
- PubMed: "Glucosamine sulfate in the treatment of knee osteoarthritis symptoms: a randomized, double-blind, placebo-controlled study using acetaminophen as a side comparator"; Arthritis Rheum; Feb, 2007
- University of Maryland Medical Center: Chondroitin Studies
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