Glucosamine

Claims, Benefits: Halts, reverses, or cures arthritis.

Bottom Line: Taken with chondroitin sulfate, this is a popular "cure" for osteoarthritis. It’s hard to recommend these supplements, unless the second phase of the new study confirms some benefit. Meanwhile, if you want to try them, it may help and seems safe.

Full article, Wellness Letter, May 2006:

The Arthritis Noncure?

Millions of Americans with osteoarthritis take glucosamine, often with chondroitin sulfate, making these two of the top-selling dietary supplements. These substances are involved in the production and maintenance of the cartilage that cushions joints, and many experts hope that supplemental doses may slow or prevent deterioration of cartilage and thus reduce pain and stiffness. But do they really work? Research has yielded conflicting findings over the years, so scientists have been waiting eagerly for the conclusion of a large, well-designed government-sponsored study that has been in the works for several years. The results finally appeared in the New England Journal of Medicine in February, and they undoubtedly disappointed most arthritis sufferers. They must have also disappointed the manufacturers of the supplements, and probably the maker of Celebrex as well.

The study included nearly 1,600 people with osteoarthritis of the knee, the joint that’s most likely to cause pain and loss of mobility. Participants were randomly assigned to receive one of five treatments daily for 24 weeks: glucosamine alone (500 milligrams three times a day), chondroitin sulfate alone (400 milligrams three times a day), glucosamine and chondroitin combined (at those same doses), a placebo (dummy pill), or Celebrex (a prescription drug approved for arthritis pain).

Overall, neither glucosamine nor chondroitin, alone or in combination, worked significantly better than the placebo. Celebrex was modestly effective. One surprising finding was that the placebo provided significant relief of symptoms in 60% of the subjects—double the expected placebo effect. Celebrex helped in 70% of them, not that much more than the placebo. At least no serious side effects were reported from the supplements or the drug.

Still unknown

Did the supplements help anyone? The one positive note was that among the 354 people with moderate to severe symptoms, 79% who took both supplements (but not either one alone) reported significant relief, versus 54% who took the placebo and 69% who took Celebrex. But because this group was small (just 70 people), the researchers said this part of the analysis was only “preliminary” and “exploratory” and that the findings need to be confirmed by additional studies.

Was this the right form of glucosamine? The study used standardized glucosamine hydrochloride. Some previous studies that had positive results used another form, glucosamine sulfate. Both forms are available here, but no one knows if one form is better. Moreover, even if you did know, you can’t be certain about the purity, potency, and quality of what you’re getting in health-food stores and drugstores or on the Internet.

Is this the last word on these supplements? Hardly. The study is now in its second phase, after which the subjects’ knees will be X-rayed to see if the supplements actually slow the loss of cartilage over the long term. Those results, expected in about a year, are crucial, since that’s supposed to be the supplements’ primary benefit (in contrast to immediate pain relief).

Bottom line

Americans spend about $10 billion a year on unproven arthritis remedies. They’ve tried almost everything to relieve arthritis pain—from cow dung poultices and countless herbs to copper bracelets and raisins soaked in gin. There is no cure, but every-thing seems to work at least for some people for a while, in part because there’s such a strong placebo effect, as this study showed. Moreover, arthritis pain waxes and wanes, and we tend to blame or credit whatever we happen to be trying at the time.

Pain relievers, over-the-counter or prescription, help many arthritis sufferers, though they don’t affect the underlying loss of cartilage. Discuss the options with your doctor. Most recommend starting with over-the-counter acetaminophen (such as Tylenol). Aspirin, ibuprofen, and naproxen may offer greater relief, but can cause stomach bleeding and ulcers. We can’t overemphasize the importance of losing weight if you are overweight, and exercising to maintain strength and flexibility. Both steps can help relieve pain and restore mobility.

What about glucosamine and chondroitin? It’s hard to recommend them now, unless the second phase of the study confirms some benefit. Don’t believe industry ads claiming that the new study has proven the benefits. Still, if you have moderate to severe symptoms, you can talk to your doctor about the supplements, along with other arthritis strategies. And if you do decide to try glucosamine, it’s probably better to choose glucosamine sulfate, based on previous research. Finally, if you already take these supplements and find that they help, continue with them, but consider stopping for a while to see if there’s a difference.

UC Berkeley Wellness Letter, May 2006

Full Article, Wellness Letter, May 2001:

Good News on Glucosamine

Cartilage cushions human joints, and when it wears down over time and the body's ability to replace it slows or ceases, the result is osteoarthritis, the most common form of arthritis. This painful and potentially disabling condition often goes along with aging.

Pain relievers, over-the-counter and prescription, are the chief medical treatment. But nearly all of these drugs increase the risk of gastrointestinal bleeding. And they do nothing to halt the advance of arthritis. Indeed, some researchers believe that these drugs can make it worse.

In European countries medicinal glucosamine has been prescribed for arthritis for many years, and more recently it has appeared on the American market as a dietary supplement. It is often taken with chondroitin sulfate. Both substances occur naturally in the body and contribute to the formation of cartilage. We haven't recommended them as supplements, alone or in combination, because the scientific evidence has been unclear, and not much is known about their long-term safety. While it has been shown that glucosamine can be absorbed and attaches to cartilage, many researchers believe that chondroitin sulfate supplements cannot be absorbed. Some think that glucosamine may make it harder for the body to process blood sugar and thus may be a problem for diabetics. Furthermore, since supplements are unregulated in this country, what's sold here may contain less glucosamine or chondroitin sulfate than stated on the label, or even none at all.

A new era for arthritis?

But a new study may be good news for glucosamine. Published in the Lancet, the study was well designed, lasted three years, and included more than 100 people. It found that people with mild-to-moderate knee arthritis who took 1,500 milligrams of purified, standardized glucosamine once a day for three years had, on average, 20 to 25% less pain and disability than those taking a placebo (dummy pill). X-ray exams showed that in those taking glucosamine, arthritis progressed slowly or not at all, while the placebo group continued to lose cartilage at the expected rate. Moreover, glucosamine produced no adverse side effects. And it did not affect blood glucose over the three-year period.

Since people in the study had only mild-to-moderate arthritis, no one knows if glucosamine would help those with severe pain. Also, the glucosamine they took was a standardized prescription medication, of consistent quality. There's no supplement here that you can count on to supply a 1,500-milligram dose.

Nevertheless, the study showed that glucosamine helped slow deterioration of cartilage and relieved pain. A large study on these supplements is underway at the National Institutes of Health, with results expected in two or three years. Meanwhile, if you want to try glucosamine, it may help and seems safe, particularly if you don't have diabetes. It's fairly inexpensive—unless combined with chondroitin sulfate, which we don't recommend. If you do decide to take it, tell your doctor.

UC Berkeley Wellness Letter, May 2001