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Health Capsules
April 2006
Supplements May Not Help Knee Pain

Many people use the popular dietary supplements glucosamine and chondroitin sulfate to treat osteoarthritis. But a new study sponsored by NIH shows that these substances—which are naturally found in and around cartilage—may not work as well as many hoped. 

Researchers led by rheumatologist Dr. Daniel O. Clegg of the University of Utah School of Medicine enrolled nearly 1,600 people with osteoarthritis of the knee in the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT). They were randomly assigned to receive 1 of 5 treatments for 24 weeks: glucosamine, chondroitin sulfate, glucosamine and chondroitin sulfate combined, a placebo or celecoxib, a pain medication.

Those taking celecoxib had less pain after 24 weeks than those taking placebo.  However, there were no significant differences between the other treatments and placebo. When the researchers looked closer, glucosamine combined with chondroitin sulfate did provide pain relief for a smaller subgroup of people with moderate-to-severe pain.

Because of the small number of people in the moderate-to-severe pain group, however, Clegg commented that the findings “should be considered preliminary and need to be confirmed in a study designed for this purpose.”

Measures of pain over a 24-week period don’t rule out the possibility that these compounds may still help with osteoarthritis. The GAIT team is continuing their research to examine whether glucosamine and chondroitin sulfate can delay the progression of osteoarthritis. The results of that study are expected in about a year.

Definitions iconDefinitions
The tissue that cushions the ends of bones within joints.

Dietary Supplements:
Vitamins, minerals, herbs and other substances meant to improve upon your diet.

A common disease caused by the breakdown of cartilage in your joints, bringing pain and limiting motion.

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Supplements: ff_osteoarthritis.htm

  Calcium and Vitamin D Trial Results

As part of the WHI (see main story), researchers looked into the effects of calcium and vitamin D supplements in healthy postmenopausal women. Researchers knew that calcium and vitamin D were important for bone health, so they wanted to see if supplements could prevent hip fractures. Some studies also suggested they might help reduce the risk of colorectal cancer—cancers of the colon or rectum, parts of the lower intestine.

Half of the over 36,000 women who joined the study received supplements while the other half got placebo pills.  The women were followed for an average of 7 years. Three-quarters were still taking their pills by the study’s end.

Overall, the supplements had no effect on spine fractures, total fractures or colorectal cancer. There was a small increase in hip bone strength for those taking calcium and vitamin D. Women in the supplement group also had fewer hip fractures than the placebo group, but the difference may have been due to chance.

Women who consistently took the full supplement dose, however, had a significant decrease in hip fractures. Those older than 60 also had fewer hip fractures with the supplements.

The supplements caused a 17% increase in kidney stones but no other ill effects.  Dr. Joan McGowan of NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases, who was a co-author of the research report, said, “Since hip fractures are considered to be more serious than kidney stones, on balance, the public health benefit of the supplements outweighs the risks.”

If you’re a woman over 60, you might consider taking calcium and vitamin D supplements for bone health. If the foods you eat contain enough calcium and vitamin D, however, you may not need supplements. Talk to your health care provider to see if they’re right for you.

Definitions iconDefinitions
A look-alike substitute with no active ingredients.  Used to compare how well an experimental treatment works.

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American Indian Health

This web site brings together a broad range of health and medical resources for people of American Indian or Alaska Native ancestry.

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