By Caroline Wilbert
WebMD Health News
Reviewed by Louise Chang, MD
May 21, 2009 -- People who suffer from acute back pain may find relief in the form of comfrey root, a plant long thought to have medicinal value.
A new study, funded by the drug company Merck and published in the British Journal of Sports Medicine, showed that people with acute back pain who used an ointment containing comfrey root extract had significant reductions in pain, compared to their peers who used a placebo ointment.
The study included 120 participants between the ages of 18 and 60, all suffering from either upper or lower back pain not caused by an identifiable source like a slipped disc or trauma. They all rubbed 4 grams of ointment on their backs three times a day for five days. Half of the participants used ointment containing comfrey root extract and half did not. Neither the participants nor the researchers knew which participants were getting comfrey root ointment and which participants were getting the placebo.
Participants were asked to assess their back pain and how much it interfered with normal movement, plus their back pain at rest.
The placebo users saw their pain intensity drop 38% during the study period, while comfrey root ointment users had a 95% reduction in pain. Back pain at rest was reduced 97% in the comfrey root group and 40% in the placebo group. The comfrey root ointment seemed to take effect in less than an hour.
The researchers report that there were few side effects. They included nausea, cold, eczema, and runny nose in four participants given the comfrey root ointment, and headache and itchiness in the three participants given placebo.
"The results of this clinical trial are clear-cut and consistent across all primary and secondary efficacy variables," the authors write in their conclusion. "Comfrey root extract shows a remarkably potent and clinically relevant effect in reducing acute back pain."
Giannetti, B.M., British Journal of Sports Medicine, 2009.
News release, Merck.
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