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 inexpensiveunless combined with
chondroitin sulfate, which we don't recommend. If you do decide
to take it, tell your doctor.
Reference
Source 98,99,101