January 4, 2005- During two recent clinical trials1, white willow extract was not found to be more effective than a placebo in relieving pain experienced by participants with osteoarthritis or rheumatoid arthritis. These studies were conducted in Germany, a country where white willow bark is frequently used for its analgesic and anti-inflammatory properties.
The researchers randomly assigned 127 adults with osteoarthritis of the knee or hip to three groups. For six weeks, a first group took a daily dosage of 240 mg of white willow extract; a second, 100 mg of an anti-inflammatory drug (diclofenac) and a third group served as a control taking a placebo.
The effect of white willow was slightly greater than that of placebo, i.e. a decrease in pain of 17% and 10% respectively, but this difference is not statistically significant. By far, diclofenac was the most beneficial in reducing pain due to osteoarthritis by 47%.
In addition, the researchers also evaluated the effect of white willow on 26 people suffering from rheumatoid arthritis. Again, white willow extract did not show any better benefits than placebo. Participants rated their symptoms by completing questionnaires commonly used for this type of study.
White willow contains salicin, which the body converts into salicylic acid, which has analgesic properties. White willow has the advantage over some drugs of not causing gastrointestinal upset, but studies to prove its true effectiveness show conflicting results. The researchers note that two studies, including one conducted in 2000, reported that white willow caused a moderate, but significant decrease in pain in people with chronic lower back pain. The authors want clinical trials to be conducted with a larger number of participants in order to more firmly establish the pain-relieving properties of this plant.
Osteoarthritis is a form of arthritis commonly associated with aging, while rheumatoid arthritis is a disease of the immune system that attacks the joints and their tissues.
Marie france Coutu – PasseportSanté.net
Version modified on August 30, 2005
According to Reuters.
1. Biegert C, Wagner I, Ludtke R, Kotter I, et al. Efficacy and safety of willow bark extract in the treatment of osteoarthritis and rheumatoid arthritis: results of 2 randomized double-blind controlled trials. J Rheumatol. 2004 Nov; 31 (11): 2121-30.
