"Although based on a sparse amount of data, the results of the present meta-analysis indicate that rosehip powder does reduce pain; accordingly it may be of interest as a nutraceutical, although its efficacy and safety need evaluation and independent replication in a future large-scale/long-term trial," state the reviewers in the journal Osteoarthritis and Cartilage.
The researchers, from Denmark's Frederiksberg Hospital, Copenhagen University Library, University of Copenhagen, and the University of California, pooled three studies including 287 patient and average trial length of three months.
Osteoarthritis effects about seven million people in the UK alone are reported to have long-term health problems associated with arthritis. Around 206m working days were lost in the UK in 1999-2000, equal to £18bn (€26bn) of lost productivity.
The reviewers, led by Professor Henning Bliddal, included randomized clinical trials only if they specifically randomized people suffering from osteoarthritis to either rosehip (hip powder of Rosa canina) of placebo. The primary outcome measure was pain reduction. Only three studies fulfilled the reviewers' criteria: Warholm et al. (2003), Rein et al. (2004) and Winther et al. (2005). In total, these studies followed 287 patients (145 patients receiving rosehip powder, 142 receiving placebo) for an average of three months, and all three were supported by the Hyben-Vital International, a Danish company specializing in manufacturing products from rosehips.
An overall reduction in pain scores was observed among the patients receiving the rosehip, with a 37 per cent reduction calculated.
"In the present analysis of R. canina hip powder, the lack of heterogeneity between studies gives credit to an efficacy. The drawback of this observation is… that the same company sponsored all three studies on R. canina hip powder," wrote the authors. "Ideally, other similar products from other manufacturers should be tested to substantiate the outcome," they added. "The results of the present meta-analysis - that R. canina hip powder does reduce pain - should be further substantiated in a large-scale (i.e., phase III) trial."
Joint health market
The joint health market is dominated by glucosamine and chondroitin sulfate, with estimated sales of $730m in the US in 2004. Glucosamine is extracted from the shell of crabs, lobster and shrimps, and also marketed by Cargill is a non-animal, non-shellfish derived product. The ingredient is often used in combination with chondroitin sulfate, extracted from animal cartilage like shark cartilage. Previous studies, including the $14m Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), sponsored by the National Institute of Health, have reported positive results, while other have reported null results, leaving the subject cloudy in uncertainty.
Source: Osteoarthritis and Cartilage
Published online ahead of print 14 April 2008, doi: 10.1016/j.joca.2008.03.001
"Does the hip powder of Rosa canina (rosehip) reduce pain in osteoarthritis patients? - a meta-analysis of randomized controlled trials"
Authors: R. Christensen, E.M. Bartels, R.D. Altman, A. Astrup, H. Bliddal