Rosehip has been used traditionally to treat a range of conditions including diarrhoea, bladder infections and diabetes. In food, rosehips are used in teas, jams, jellies and soups, and as a natural source of vitamin C. The vitamin C content of fresh rosehips is higher than that found in citrus fruits. Rosehip is also high in folate and contains vitamins A, B3, D and E along with flavonoids, carotenoids, betasitosterol, fructose, malic acid, tannins, magnesium, zinc, copper and numerous other phytochemicals including recently characterised galactolipids.1–4
These nutrients can be depleted or destroyed during processing and the content of phytochemicals has been shown to be sensitive to the maturity of the fruits as well as drying time, drying air temperature and moisture content.5–8
A team from the Department of Clinical Biochemistry at the University of Copenhagen in Denmark has been involved in researching and testing rosehip for over a decade. This research has focused on a specific rosehip powder produced by Hyben Vital, Denmark.
The production process involves plants grown according to good agricultural practice in standardised fields in Denmark and Sweden. Fruits are harvested when they are fully ripe and optimal fruits are selected using a laser technique.9 This patented process preserves the nutrient content and the resultant powder is standardised to contain at least 5 mg/g of vitamin C. The product consists of seeds as well as shells.
The standardised extract has been available for more than a decade in Scandinavia as a herbal remedy.9 It is now readily available in Australia and New Zealand under the trade name Rose-Hip Vital™.
Therapeutic activities of rosehip
Rosehip is rich in polyphenolic compounds such as proanthocyanidins and flavonoids such as quercetin and catechin.8 The high phenolic and flavonoid content of rosehips has been observed to correlate with antioxidant activity10 and when rosehip extract containing these phenolics is deprived of vitamin C it still shows considerable antioxidant activity.11 This activity includes protective effects against oxidative stress, enhanced activity of antioxidant enzymes such as superoxide dismutase and catalase, and protective effects on gap junction intercellular communication.12
Rosehip has been found to have antiinflammatory and antinociceptive activities in several in vivo experimental models with synergistic interactions between compounds.13 The anti-inflammatory power of rosehip is reported to be similar to that of indomethacin, although its mode of action is different.14 The lipophilic constituents have been found to be particularly active with respect to antiinflammatory properties including actions on arachidonic acid metabolism and inhibition of both cyclooxygenase-1 and 2.10 Much of the anti-inflammatory action of rosehip has been attributed to high quantities of galactolipids, a class of compounds recently shown to possess antitumour promoting and anti-inflammatory activity, both in vitro and in vivo.4 Rosehip and its constituent galactolipids have also been found to inhibit the production of inflammatory mediators and confer chondroprotective effects in vitro.15
A particular galactolipid – GOPO® – has been shown to be the active principle responsible for the observed in vitro inhibition of chemotaxis and chemiluminescence of human peripheral blood leucocytes without any toxicity to the cells.16–19 This suggests GOPO® is important for the clinically observed anti-inflammatory properties of standardised rosehip powder, which include reduced serum c-reactive protein (CRP) and creatinine levels in patients with osteoarthritis and healthy subjects,18,20 as well as improved pain and joint movement in osteoarthritis patients.1,21
In contrast to nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin, rosehip has anti-inflammatory actions that do not have ulcerogenic effects and do not inhibit platelets or influence the coagulation cascade or fibrinolysis,22 thereby avoiding potential side effects for patients who may be at increased risk from the gastrointestinal or cardiovascular side effects of NSAIDs.19
Antidiabetic, lipid lowering and anti-obesogenic activity
Rosehip has been used as a traditional treatment for diabetes and has recently been found to possess hypoglycemic effects in diabetic rats.23 Similarly, rosehip extract has been reported to significantly reduce blood glucose levels after glucose loading, as well as substantially inhibiting weight gain and/or accumulation of visceral fat without affecting food intake in mice.24 Rosehip has also been found to produce modest lowering of total cholesterol in humans.1 While these activities are promising, they await further confirmation in large human clinical trials.25
Clinical research on standardised rosehip powder
Since the patenting of standardised rosehip power, there has been a number of clinical trials exploring the efficacy of this preparation in conditions such as osteoarthritis, rheumatoid arthritis and inflammatory bowel disease. It should be noted that all clinical research on rosehip has been performed on the standardised, patented extract with the trials being supported by the manufacturer, Hyben Vital. Clinical research into this extract includes open label and randomised controlled trials with a duration of 6 months or less, along with a number of corresponding systematic reviews and meta-analyses. These studies have consistently found rosehip to be extremely safe, with occasional mild allergic reactions or gastrointestinal complaints but no serious adverse effects.26 In January 2011, the evidence for rosehip was reviewed by Arthritis Australia and for the first time rosehip was included in the Arthritis Australia complementary medicine information sheet.27
Randomised controlled trials
Osteoarthritis, rheumatoid arthritis and back pain
The first randomised controlled trial of rosehip involved 100 patients with painful, radiographically verified osteoarthritis of the hip or knee. These patients, some of who were end stage and awaiting joint replacement, were randomised to receive either 2.5 g standardised rosehip powder or placebo twice daily for 4 months. Results showed that in comparison with placebo, rosehip powder significantly reduced pain (p=0.035) with 64.6% of patients receiving rosehip reporting at least some reduction of pain. Rosehip-treated patients also experienced improved hip flexion (p=0.033) with no significant change observed for internal and external rotation of the hips or knee flexion.21
A second double blind, placebo controlled, crossover study involving 112 patients with osteoarthritis of the hip, knee, hand, shoulder or neck, found that compared to those receiving placebo, patients who received 5 g/day of standardised rosehip powder for 3 months experienced significant reductions in pain (p<0.0078) and stiffness (p<0.0025), as well as significant improvements in mood, wellbeing and sleep quality. Sixty-six percent of patients receiving active treatment reported improvement in pain compared to only 36% of placebo patients. Reductions in paracetamol consumption and plasma CRP along with a small but significant reduction in total cholesterol were also observed. After the treatment and placebo groups were crossed over for a further 3 months (without a washout period) no difference was seen between the two groups, suggesting that rosehip has a long duration of action with a strong carryover effect.1
A third placebo controlled, double blind crossover trial involving 94 patients aged over 35 years with osteoarthritis of the hip or knee, randomised patients to either placebo or 5 g/day or rosehip for a period of 3 months. Compared to placebo, treatment with rosehip resulted in a significant reduction in WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) pain (+/–) and consumption of 'rescue medication' after 3 weeks and significant reduction in WOMAC disability, stiffness and global assessment of severity of the disease after 3 months of treatment.28
In addition to offering benefits for patients with osteoarthritis, rosehip may offer benefits in other conditions such as back pain and rheumatoid arthritis. A 1 year surveillance of 152 patients found that rosehip provided significant pain relief for patients with acute exacerbations of chronic back pain.29 More recently, a 6 month, double blind placebo controlled trial also found modest benefits for patients with rheumatoid arthritis indicated by significantly improved scores on the Health Assessment Questionnaire Disability Index (HAQ-DI) along with various other patient and physician reported scales. The authors concluded that while the results were promising, the study was not well powered and larger studies were needed.30
A slow onset of action, modest effect size and lack of statistical power may account for the results of a more recent and much smaller open case control study of 20 female patients with rheumatoid arthritis and 10 female controls, which found no significant effects on clinical symptoms, level of CRP or laboratory measures of antioxidant enzyme activity after 4 weeks of treatment with 10.5 g/day of rosehip powder.31
Meta-analyses and systematic reviews
A meta-analysis of the three randomised controlled trials of osteoarthritis patients included 287 patients with a median treatment period of 3 months. This meta-analysis reported that treatment with patented rosehip powder consistently reduced pain scores and that patients were twice as likely to respond to rosehip (as indicated by a reduction in WOMAC pain) compared to placebo (effect size of 0.37, 95% CI: 0.13–0.60). The authors therefore concluded that rosehip powder does reduce pain and that its efficacy and safety need evaluation and independent replication in future large scale, long term trials.32
A more recent meta-analysis provides an indirect comparison of the pain reducing effect of glucosamine hydrochloride and standardised rosehip powder for osteoarthritis. This analysis, which was based on three studies on glucosamine hydrochloride involving a total of 933 patients and the three studies described above involving 287 patients, concluded that rosehip is more efficacious than glucosamine hydrochloride in reducing pain in osteoarthritis patients.33
As well as being the subject of metaanalyses, the clinical trials of rosehip have been systematically reviewed. One systematic review of two relatively small (n=100 and 112) double blind, randomised placebo controlled studies, both of which were considered to be of high quality with a Jadad score of 5 out of 5, concluded that rosehip powder had a moderate effect in patients with osteoarthritis.34 This same conclusion was also made by another systematic review that included four trials (two of which were identified as subgroup analyses).35
The growing evidence base for rosehip suggests that this traditional herbal remedy has a high safety profile. While further research is required to establish its clinical role, existing research (both in vitro and in vivo) suggests that standardised rosehip powder may offer an effective first line therapy and is a viable replacement or supplement for conventional drug therapies such as NSAIDs in osteoarthritis and possibly other inflammatory diseases.
Conflict of interest: The author has received payment from Brand New Solutions for time spent writing this article and consultancy fees for writing media reports on Rose-Hip Vital™.