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NEW YORK (Reuters Health) - A dietary supplement derived from chickens may bring some pain relief to people with mild knee arthritis, preliminary research suggests.
The supplement contains a high concentration of hyaluronic acid (HA), a natural substance in the body that lubricates and cushions the joints. HA injections directly into the knee joint are sometimes used to treat more-severe cases of arthritis.
The new study, reported in Nutrition Journal, looked at whether an oral HA supplement might help relieve pain in people with milder knee arthritis. The supplement, like the products used for injections, contains HA extracted from chicken combs -- the flesh that caps chickens' heads.
Researchers found that among 20 adults with knee arthritis, those who took the HA supplement for eight weeks reported greater pain relief and improvements in physical function than those who were given inactive, placebo pills.
The findings suggest that oral HA supplements might be beneficial as an additional treatment for people with milder knee arthritis, lead researcher Dr. Douglas S. Kalman, of Miami Research Associates, told Reuters Health.
But he said he does not see the supplements as a "replacement" for HA injections, since they are typically used for people with more severe arthritis.
Kalman and his colleagues studied a supplement already on the market called Hyal-Joint. Bioiberica, the Barcelona-based maker of Hyal-Joint, funded the study; the researchers have no financial ties to the company.
The study included 20 men and women age 40 and up with milder-stage knee arthritis. Half were randomly assigned to take 80 mg of the HA supplement every day for eight weeks; the rest were given identical-looking but inactive capsules.
By the end of the study, both groups were reporting improvements in their pain and joint function. The gains were greater, however, in the supplement group.
The results suggest that oral HA supplements stand as one more weapon in the armament against knee arthritis, according to Kalman. But if people try them, he said, it should be in addition to any standard therapy they are using, like physical therapy or nonsteroidal anti-inflammatory medication.
Injectable HA is thought to help knee arthritis, in part, by improving elasticity in the synovial fluid that bathes the joint. It's not clear how oral HA supplements stack up against the injected form.
However, Kalman said past research has found that oral HA does seem to be "bioavailable" -- meaning the substance can be absorbed and used by the body.
SOURCE: Nutrition Journal, online January 21, 2008.
