Ginger extract similar to celecoxib for OA relief

In comparison study, pain and stiffness reduced by 40% compared to placebo

By Kylie Taggart

TORONTO – Results from a clinical trial show a new extract of two ginger species reduced osteoarthritis pain and stiffness in knee joints by 40% compared to placebo. The findings are comparable to benefits seen with the COX-2 inhibitor celecoxib (Celebrex).
   The extract, marketed by Jamieson Laboratories under the name Zinaxin EV.EXT 77, is standardized so the dose of ginger remains constant. The extract is derived from the ginger species Zingiber officinale and Alpinia galanga.
   Dr. Roy Altman, principal investigator of the study and chief of the division of rheumatology and immunology at the University of Miami school of medicine, said the extract could be used as part of regular treatment for osteoarthritis. He said it would fit in at the level of care when physicians are prescribing medications with few side-effects, such as acetaminophen, before going to drugs like non-steroidal anti-inflammatories, analgesics or steroids.
   "I think a product like this, which has such a good effective profile as well as a good safety profile, fits right in there at that level of care," he said during a recent visit to Toronto.
   The trial involved 247 patients with osteoarthritis. They were randomized to either the ginger extract or a placebo twice daily for six weeks. The patients were asked to rate their pain using a 100 mm visual analogue scale. The Western Ontario and McMaster universities osteoarthritis composite index (WOMAC) was also used to measure pain.
   After two weeks, patients on the ginger extract had 30% less pain on standing compared to the placebo group. At six weeks, the reduction was 40%.
   The pain after walking 15 metres was decreased by 17% from baseline in the placebo group at six weeks, but by 30% in the ginger extract group.
   The WOMAC scores, which measure pain, stiffness and function, showed a trend in favour of the ginger extract.
   There was a strong placebo effect, with about half the patients in the placebo group reporting an improvement in pain on standing. However, the differences between the ginger group and the placebo group were all significant, except for the WOMAC scores. Dr. Altman was not concerned with the large placebo effect.
   "In osteoarthritis if you don't see around 30% placebo response, you probably shouldn't believe the study," he said.
   In a comparison with results from a trial published in the journal Clinical Therapeutics last year, the ginger extract had similar effects as 100 mg and 200 mg celecoxib. Using a visual analogue scale, the patients on celecoxib had a similar reduction in knee pain to those on ginger in Dr. Altman's study. The placebo group in the celecoxib trial also responded in a similar manner to the placebo group in Dr. Altman's trial.
   Although the comparison might be a rough one, Dr. Altman said: "It is pretty impressive to show that the ginger has virtually the same effect as a COX-2 inhibitor."
   There were some adverse events with the ginger extract. Patients in the ginger group experienced mild gastrointestinal side-effects such as dyspepsia, nausea and burping. Thirteen per cent of patients in the ginger group withdrew because of adverse events, compared to 5% in the placebo group.
   Another problem was a strong ginger taste with the ginger extract. This taste may have interfered with blinding in the study, but subanalyses showed the patients who did not report the strong taste still showed benefit compared to placebo, Dr. Altman said.
   The extract released by Jamieson Laboratories has a different coating than the one tested in Dr. Altman's trial. Dr. Lars Lindmark, director of research and development at Eurovita International in Soeborg, Denmark, the company which developed the extract, said he headed a trial with the new formulation and found there was a reduction in gastrointestinal adverse events.
   Whether the extract poses a risk of interacting with other drugs is unknown. "We really don't have any information on this at all. We're using ginger, which has centuries of experience, but we are using a very highly concentrated form of ginger. Certainly you're not going to be able to do this by going to the grocery store and taking home the ginger from there. First of all it's a different ginger from the one at the grocery store and second of all you'd have to eat ginger all day long in order to get enough of the ginger that we have in these capsules," Dr. Altman said.
   Dr. Lindmark said the company will do postmarket research to watch for drug-drug interactions, although that research is difficult to conduct in over-the-counter herbal medications.
   For centuries, ginger has been used for nausea, air sickness and morning sickness during pregnancy, among other complaints. In Chinese medicine it is used in rheumatic disorders. Its action in osteoarthritis is not fully understood, but may interact with prostaglandins as COX-2 inhibitors do.
   "We really don't know. It seems to have some mild effects on prostaglandins, but the most exciting work has come out of Johns Hopkins University, suggesting that it might interfere with TNF (tumour necrosis factor). That is considerably different from the COX-2 inhibitors, which are specifically for prostaglandin inhibition," Dr. Altman said.
   It is known that both TNF and IL-1 are involved in osteoarthritis.
   Dr. Altman said he looks forward to further research involving the extract.
   "I think there need to be future studies. I think there need to be longer studies as this is only a six-week-long study. I think since this looks so impressive, we really need to do a head-to-head study comparing the COX-2 inhibitors with the ginger. It may have to have a two-by-two design, seeing if you can combine the ginger with the COX-2 inhibitor to see if there is an additive effect," he said.
   Dr. Altman's study was published in the journal Arthritis and Rheumatism.