Effectiveness of glucosamine and chondroitin sulfate for osteoarthritis

Osteoarthritis treatments
Conventional medicine does not yet have a proven treatment to stop or slow the progression of osteoarthritis. The nutritional supplements, glucosamine and chondroitin sulfate, have emerged as a treatment alternative for some patients suffering from osteoarthritis pain.

Perhaps the most important aspect of glucosamine and chondroitin sulfate supplements is that they are thought to help slow or prevent the degeneration of joint cartilage, the underlying cause of osteoarthritis pain. Glucosamine and chondroitin sulfate dietary supplements may also help alleviate existing joint pain. Presently, it is thought that unlike many medications available to treat arthritis pain and inflammation, glucosamine and chondroitin sulfate supplements have very few side effects.

Osteoarthritis – a degenerative joint condition
Osteoarthritis occurs when the cartilage on the ends of the joints wears down and the exposed bones rub together. This degenerative process causes excess friction in the joints, which leads to loss of motion, stiffness and joint pain. Osteoarthritis is more common among middle-aged and older individuals. Symptoms can range from mild to very severe pain in the back, neck, hands, hips, knees and/or feet. When degenerative osteoarthritis occurs in the back, it is usually referred to as facet joint osteoarthritis (because it affects the facet joints in the spine). When occurring in the neck, it is usually called cervical osteoarthritis.

Glucosamine and chondroitin sulfate dietary supplements
Glucosamine and chondroitin sulfate are naturally found in connective tissues in the human body, such as those covering the ends of bones in the joints. Glucosamine is extracted from animal tissues such as crab, lobster or shrimp shells, while chondroitin sulfate is found in animal cartilage such as tracheas or shark cartilage (1). They are commonly taken as dietary supplements (also known as nutritional supplements).
Glucosamine and chondroitin sulfate are believed to impact the cartilage degeneration process of osteoarthritis in the following ways:

• Glucosamine sulfate is thought to help with cartilage formation and repair (1). Some laboratory tests show that glucosamine sulfate may help protect joint cartilage by limiting breakdown and helping to build up levels of cartilage (2). Glucosamine hydrochloride, another form of glucosamine, is considered to be equally effective as the sulfate form. It is absorbed more easily by the body and can be taken in lower dosages with the same effectiveness as glucosamine sulfate.
• Chondroitin sulfate is part of a protein molecule that helps give cartilage its elastic properties and is thought to have an anti-inflammatory effect, which can help to reduce the painful swelling in the joints that occurs when the exposed bones in the joint rub together (3). In addition, chondroitin sulfate may also help slow the breakdown of cartilage and help restore cartilage growth to better cushion the joints (2).

Combining nutritional supplements with other treatments
Glucosamine and chondroitin sulfate may not provide sufficient pain relief for all osteoarthritis patients. Many patients find it is best to use glucosamine and chondroitin sulfate nutritional supplements in conjunction with other conservative treatments (under the guidance of their treating physician), such as:

• Traction for cervical osteoarthritis and/or chiropractic manipulations  can help to control the chronic pain and other symptoms of osteoarthritis, as well as provide relief from severe episodes of pain. Patients considering traction should always work with a physician to ensure correct and safe use of the traction devices, as improper application of traction can be detrimental.
• Gentle stretching exercises can help maintain flexibility and range of motion as well as reduce stiffness in the muscles and joints. Engaging in gentle physical activity may also help maintain overall back health even after a flare-up of osteoarthritis pain is relieved.
• Water therapy(specific exercises performed in a pool) can help patients with severe osteoarthritis pain. Pool therapy allows the joints to be unweighted by the water, which may be less painful than other types of exercise. Another gentle form of exercise is using an elliptical machine or a stationary exercise bike, which provide forms of aerobic exercise that are low-impact on the joints.
• Pain medication that has anti-inflammatory properties, such as ibuprofen, COX-2 inhibitors, naproxen and other non-steroidal anti-inflammatory drugs (NSAIDs). Acetaminophen may also be helpful for relief of joint pain associated with osteoarthritis. Taking glucosamine and chondroitin sulfate nutritional supplements may reduce some patients’ need for anti-inflammatory or pain medications, while others may continue to take other medications for pain relief. However, patients taking daily aspirin therapy should avoid taking chondroitin sulfate supplements, as it may contribute to bleeding.

Additional non-medical approaches (e.g. acupuncture, yoga or Tai Chi, instrument assisted soft tissue techniques such as Active Release Technique (ART), Graston Technique (GT), muscle energy techniques, proprioceptive neuromuscular rehabilitation (PNF), Nimmo method, massage and others) may also be effective for some patients. Sometimes rest or weight loss may be recommended for certain patients in order to reduce stress on the joints. Some patients may also require a short period of rest and medication to reduce joint inflammation before they begin to exercise.
The proper course of treatment will differ for each patient and should be supervised by a health professional.

Glucosamine and chondroitin sulfate contraindications and warnings
It is known that the following groups of patients should only take the supplements under close medical supervision or should avoid them altogether:

• Diabetic patients should only use glucosamine sulfate supplements under close medical supervision, as some studies suggest that glucosamine sulfate may increase insulin resistance.
• Patients who are allergic to shellfish should consult their physician before taking glucosamine sulfate supplements. However, an allergy to shellfish does not usually pose a limitation for taking glucosamine sulfate, as glucosamine sulfate is extracted from chitin, a carbohydrate, whereas shellfish allergies are most often caused by a protein (1).
• Children, as well as women who are pregnant and/or nursing, or who could become pregnant. There is currently not enough research available to determine whether or not taking glucosamine and chondroitin sulfate supplements has negative effects on young children or fetuses (1).
• Patients taking blood-thinning medications(anticoagulants) or daily aspirin therapy should not take chondroitin sulfate, as it may contribute to bleeding (1).

Patients who have any adverse reactions or unusual side effects to glucosamine and/or chondroitin sulfate supplements should discontinue use immediately and consult their physician.

Dosage for glucosamine and chondroitin sulfate dietary supplements
The generally accepted daily dosages for the nutritional supplements are the following:

Patients who are obese or who weigh over 200 pounds should discuss proper dosage with their physician, as they may need to take higher levels of glucosamine and chondroitin sulfate. Both types of dietary supplements are available in capsule form over-the-counter (without a prescription). Glucosamine and chondroitin sulfate dietary supplements are often sold in combination formulas, and some patients find this easier to take.

Nutritional/dietary supplements are not regulated
Finally, it is important to reiterate that both glucosamine sulfate and chondroitin sulfate nutritional supplements are not subject to the same strict regulations and FDA oversight as are other types of medications, so both the quality and the content/ingredients of the supplement capsule may vary between brands. Therefore, patients need to be especially diligent about researching and using high quality brands. It is advisable for patients to talk to their physician and/or pharmacist about specific brands.

Glucosamine and chondroitin sulfate may help with optimal pain relief
It is certain that further research on glucosamine and chondroitin sulfate is still needed. However, the lack of more effective traditional medical treatments for osteoarthritis and the low incidence of side effects from glucosamine and chondroitin sulfate present the nutritional supplements as a viable treatment alternative for some patients with osteoarthritis. Combined with other osteoarthritis treatments (as deemed appropriate by a physician), taking glucosamine and chondroitin sulfate dietary supplements may help some patients attain optimal levels of relief from osteoarthritis-related joint pain.
As more information becomes available, it is important for all patients to follow the recommended guidelines for taking glucosamine and chondroitin sulfate nutritional supplements (as well as other types of dietary supplements) and to remain under supervision of a physician throughout the duration of treatment.
By: Thomas E. Hyde, DC

Reference:

1. Arthritis Foundation. “Alternative therapies: glucosamine and chondroitin sulfate.” 2004. http://www.arthritis.org/conditions/alttherapies/Glucosamine.asp#Whatare.

• Deal, C.L.: “Neutraceuticals as Therapeutic Agents in Osteoarthritis.” Rheumatic Disease Clinics of North America. 1999: 379-395.
• National Institutes of Health. National Center for Complimentary and Alternative Medicine. “Questions and Answers: NIH Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT).” 2004. http://nccam.nih.gov/news/19972000/121100/qa.htm.

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