The use of food or nutrient supplements to alleviate symptoms of rheumatic disease, or to attempt to prevent the onset of osteoarthritis (OA), has become endemic in Europe and North America. However, the degree of benefit a particular patient obtains from the use of products such as glucosamine, omega oils and plant derivates remains hard to assess.
Any evaluation is complicated by the uncertain content and purity and lack of regulation of some OTC supplements, together with high expectations of benefit from consumers, leading to a substantial placebo effect that can be associated with 'natural' remedies.
As a rheumatologist usually involved with the prescription of pharmaceutical drugs that have been tested in extensive clinical trials, the widespread purchase and use of supplements by patients with rheumatic disease remains of great interest to me.
From the perspective of possible efficacy of the products, and as a social trend that appears to be on the increase, their use can be considered to be part of the effort made by the patient to develop self-management strategies independent of traditional medicine and medications.
Rosehip extract was shown in some studies to relieve pain in OA |
Glucosamine
The supplement with probably the best track record in clinical research is glucosamine: glucosamine sulphate has been shown to have analgesic effects in OA of the knee and possible cartilage-preserving properties that may slow the onset and progression of OA.
The market for glucosamine in the UK alone has been estimated to be in excess of £80 million a year. There is still some debate about the relative efficacy of glucosamine sulphate versus the hydrochloride salt and the efficacy of certain brands compared with others.
Rosehip extract
Another supplement that has appeared on the shelves in the UK is rosehip powder, made from the rosehips and seeds of a subtype of the common dogwood briar rose, Rosa canina.
Rosehips are rich in vitamin C and used to be collected to make rosehip syrup, which became a standard family supplement when other sources of vitamin C became scarce during and after World War II in the UK.
Evidence for use
Claims have been made that rosehip extracts relieve pain in OA and rheumatoid arthritis (RA) and there is a reasonable amount of research to support this. A meta-analysis of randomised controlled trials has recently been published that examines the use of rosehip powder as an analgesic in symptomatic OA.1
Three studies were identified2-4 in which patients were randomised at inclusion to either extracts of Rosa canina or placebo and were assessed for pain relief.
These studies involved a total of 287 patients treated for a median trial period of three months. The methodology of the meta-analysis itself appears very rigorous and none of the authors had any financial association with manufacturers of Rosa canina products.
All three randomised trials analysed were performed in Scandinavia and were supported by Hyben-Vital International, a firm based in Denmark manufacturing rosehip powder. The authors point to the pharmaceutical support from the one company alone and conclude that studies using other products from other manufacturers may be advisable in the future.
Within the studies analysed, 153 patients received 5g daily rosehip extract powder (62 per cent women with a median age of 66 and all with OA hip or knee). Pain relief with rosehip powder in OA was seen across all three trials and was significantly better than with placebo, leading patients to use fewer standard analgesics. Patients with OA were more than twice as likely to experience pain relief with rosehip powder than with placebo.
The review concludes that moderate evidence exists for the effectiveness of rosehip powder for pain relief in OA, and that the lack of adverse effects meant rosehip powder could be considered safe enough to be suitable for OTC purchase, as is presently the case.
Anti-inflammatory action
One of the pain relieving effects of rosehip powder in OA may be due to an active ingredient, a galactolipid known as glycoside of mono- and diglycerol (GOPO).5
In vitro studies suggest that GOPO may be anti-inflammatory, working via pathways of reduced neutrophil chemotaxis and antioxidative effect.
OA can be considered not simply a degenerative condition but to have an inflammatory component, which may be responsive to agents such as GOPO.
If GOPO, and rosehip powder in general, is acting as an anti-inflammatory, it would seem appropriate to consider a possible role in symptom relief in a more overtly inflammatory condition such as RA.
A study of 89 patients with RA looked at the possible pain relieving effect of rosehip powder versus placebo.6
Rosehip powder showed definite benefit in reducing tender joint count and improving health-related quality of life while pain scores showed no significant benefit.
Further studies need to be done in RA and other related conditions.
Cost
Rosehip extract is not cheap, and regular or long-term use can potentially cost patients a lot of money.
The manufacturers suggest - rather empirically - that high doses are used initially (two capsules three times daily at a cost of around £30 per month) followed by two capsules twice daily.
Personally, I support the use of supplements in attempting to relieve pain in rheumatic disease. They appear safe, avoid the gastro-intestinal problems that are associated with NSAIDs by potentially leading to decreased usage. They are also very popular with patients and may have some benefit through pathways of either pain or inflammation.
Rosehip powder has advantages over some of the other supplements in showing effect in both OA and RA.
There is enough evidence of efficacy to make it worthwhile for patients to use it for a trial period - perhaps one to three months - if they wish.
Rosehip powder is rich in vitamin C and, as with other supplements, is likely to have a significant added placebo effect leading to pain relief.
In neither OA nor RA should rosehip powder, or other supplements, substitute for other treatments such as proven disease-modifying medication in RA and exercise, weight loss and joint care in both RA and OA.
- Dr Hughes is consultant rheumatologist at St Peter's Hospital, Chertsey
- Dr Hughes has previously provided paid consultancy work on Litozin (rosehip extract) for Spink PR
- 12 October is World Arthritis Day. For more information visit www.worldarthritisday.org
References
1. Christensen R, Bartels E M, Altman R D, Astrup A, Bliddal H. Review: Does the hip powder of Rosa canina (rosehip) reduce pain in osteoarthritis patients? - a meta-analysis of randomized controlled trials. Osteoarthritis Cartilage 2008 doi:10.1016/j.joca.2008.03.00.
2. Winther K, Apel K, Thamsborg G. A powder made from seeds and shells of a rose-hip subspecies (Rosa canina) reduces symptoms of knee and hip osteoarthritis; a randomized, double-blind, placebo-controlled clinical trial. Scand J Rheumatol 2005; 34: 302-8.
3. Warholm O, Skaar S, Hedman E, Molmen H M, Eik L. The effects of a standardized herbal remedy made from a sub-type of Rosa canina in patients with osteoarthritis; a double-blind, randomized, placebo-controlled clinical trial. Curr Ther Res Clin Exp 2003; 64: 21-31.
4. Rein E, Kharazmi A, Winther K. A herbal remedy, Hyben Vital (stand. powder of a subspecies of Rosa canina fruits), reduces pain and improves general wellbeing in patients with osteoarthritis - a double-blind, placebo-controlled, randomised trial. Phytomedicine 2004; 11: 383-91.
5. Kharazmi A, Winther K. Rose hip inhibits chemotaxis and chemiluminescence of human peripheral blood neutrophils in vitro and reduces certain inflammatory parameters in vivo. Inflammopharmacology 1999; 7: 377-86.
6. Rossnagel K, Roll S, Wagner A et al. Can patients with rheumatoid arthritis benefit from the herbal remedy rose-hip? Rheum Dis 2007; 66: 603.
