Dietary Supplements For Osteoarthritis
(OA) is one of the most common forms of arthritis and can lead to chronic pain and disability.
Joint Wear and Tear
Degenerative joint disease, another term for OA, is a better description of the process of wear and tear that gradually softens and breaks down the joint cartilage that normally prevents bones from rubbing together.
of osteoarthritic joints often show narrowing of the joint space and destructive changes in the adjacent bone.
People with OA have joint pain and stiffness, particularly after physical activity. The hips, knees, ankles, and spine are most susceptible to OA since they absorb the brunt of gravitational forces. The fingers and neck are also prone to OA.
Joint cartilage is made up of cells, called chondrocytes, embedded in a substance called the extracellular matrix. One of the primary components of this matrix is a material called proteoglycan. This material helps cartilage absorb the forces of friction.
With normal aging, the proteoglycan content of the matrix decreases. This decrease can be accelerated by injury, excessive mechanical force, or joint deformity. This explains why certain occupations, like machine operators and athletes, become disabled from OA sooner than the rest of us. It also explains why
, which adds considerable stress to joints of the lower extremities, greatly increases the risk of OA, particularly in the knees.
Even after OA begins to set in, there is evidence that regular exercise can delay or prevent the onset of pain and disability. Aerobic activity protects against obesity, while weight training enhances the strength and flexibility of the muscles, tendons, and ligaments around the joints, which improves joint stability and resilience. Keep in mind that acute injuries and repetitive strain increase the risk of OA. Therefore, exercise is only beneficial to joint health if it is done gradually and with proper preparation and equipment.
Standard treatments for symptomatic OA include:
- Physical therapy to increase the strength and flexibility of affected joints
- Prescription or nonprescription pain medication, such as nonsteroidal anti-inflammatory drugs (NSAIDs)
- Direct injections of more powerful anti-inflammatory steroid medication into the joint
- Direct injections of hyaluronic acid to help with joint lubrication
- Joint replacement surgery
Although often effective at relieving pain, these interventions do nothing to slow or reverse the deterioration of cartilage. Therefore, researchers have turned their attention to 2 natural constituents of human cartilage thought to preserve, or even enhance, cartilage integrity—
Glucosamine and Chondroitin
Glucosamine and chondroitin are thought to stimulate the production of proteoglycan and stop its breakdown. Glucosamine is derived from the exoskeletons of shrimp, lobster, and crabs. Chondroitin is manufactured from natural sources, such as shark and bovine cartilage.
Numerous clinical studies have evaluated the effectiveness of these supplements in treating OA of the knee and hip. Some studies have shown glucosamine and/or chondroitin to be moderately more effective than a placebo, with no significant side effects. However, more recent studies have not shown these supplements to be effective. In fact, many of the studies that had positive results were funded by manufacturers of these products. Studies done by neutral researchers failed to find benefits.
Other Supplements for OA
Glucosamine and chondroitin are not the only natural products that have been tried as possible treatments for OA. Researchers have studied many other supplements, like:
- S-adenosylmethionine (SAMe)–There is some evidence that SAMe may relieve the symptoms of arthritis and be as effective as anti-inflammatory medication.
- Avocado/soybean oil extracts–The results so far are promising for these extracts in treating OA.
- Cetylated fatty acids—These naturally occurring fatty acids, which are available as an oral supplement and a cream, have also shown some promise.
Your Next Move
If you are interested in trying a natural approach to relieve OA, make an appointment with your doctor. This is an important step because in some cases, supplements may interact with other medications that you are taking or affect other conditions that you may have. Also, since these types of products are not regulated by the US Food and Drug Administration (FDA), it is difficult to know the purity of the supplement. Keep in mind, too, that researchers continue to study ways to help people find relief from joint pain and stiffness, so a new treatment may soon be discovered.
National Center for Complementary and Integrative Medicine
Seniors—Government of Canada
The Arthritis Society
Degenerative joint disease of the hip. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated April 20, 2015. Accessed January 21, 2016.
Degenerative joint disease of the knee. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 29, 2015. Accessed January 21, 2016.
Osteoarthritis. Arthritis Foundation website. Available at: http://www.arthritis.org/about-arthritis/types/osteoarthritis. Accessed January 21, 2016.
Osteoarthritis. EBSCO Natural and Alternative Treatments website. Available at: http://www.ebscohost.com/biomedical-libraries/natural-alternative-treatments. Updated September 2014. Accessed January 21, 2016.
Osteoarthritis prevention: What you can do. Arthritis Foundation website. Available at:
http://www.arthritis.org/about-arthritis/types/osteoarthritis/articles/oa-prevention.php. Accessed January 21, 2016.
DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed: Wandel S, Jüni P, Tendal B, et al. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ. 2010;341:c4675.