There is little conclusive evidence to justify the wide-spread use of herbal medicines to relieve the symptoms of osteoarthritis according to a comprehensive review of these products in the latest issue of the Drug and Therapeutics Bulletin (DTB).
It’s estimated at least eight million people in the UK have osteoarthritis: a painful condition which causes pain and stiffness in and around the joints-usually the knees, hips and fingers.
Treatment options include exercise; the use of heat or cold; simple analgesics and corticosteroid injections but many people also try to relieve symptoms with the use of alternative therapies such as herbal medicines.
However, the DTB review found there is a lack of licensed herbal medicinal products on the market for the symptoms of osteoarthritis and none specifically licensed for the illness.
Arthritis Research UK say the review very much followed the results from its own study of complementary medicines for arthritis, which showed that few products were effective in relieving osteoarthritis symptoms.
Herbal medicines traditionally used to treat osteoarthritis include vegetable extracts of avocado or soybean oils (ASUs), cat’s claw, devil’s claw, Indian frankincense, ginger, nettle, rosehip, turmeric and willow bark.
However, the DTB cautions that few studies on the use of herbal medicines for osteoarthritis have been carried out. It says those that have frequently contain design flaws and limitations all of which compromise the validity of the findings.
According to the review the DTB found that the limited clinical trial evidence indicates that ASUs, Indian frankincense and rosehip, may work and appear to produce few unwanted side effects. However, it adds that more robust data is needed.
As to the rest, including cat’s claw, devil’s claw, ginger, nettle, turmeric and willow bark, it says the evidence in favour of their use is at best equivocal or unconvincing. With the exception of devil’s claw, no authorised products containing these ingredients for the use of osteoarthritis have been registered in the UK. However, the UK Medicines and Healthcare products Regulatory Agency (MHRA) has approved Traditional Herbal Registrations for several herbal medicinal products containing devil’s claw for rheumatic symptoms.
Unlike licensing for mainstream medicines, registration doesn’t mean a herbal remedy has been tested and proven to actually work. It does mean the MHRA is satisfied the product is made to good quality standards with appropriate labelling. It also means the herb has been used in traditional remedies for more than 30 years.
Arthritis Research UK’s own study awarded alternative medicines marks between one and five for effectiveness. Capsaicin gel, made from chilli peppers, which is available from the GP on prescription, proved most effective in relieving pain and joint tenderness, scoring the full five.
“We know that people with osteoarthritis try complementary medicines because of the lack of effective conventional medication treatment, especially pain relief, but they should bear in mind that most of these products have limited benefit, and some can even be harmful,” said Jane Tadman from Arthritis Research UK in an email.
So herbs may be ineffective as a treatment but can still have a big effect. The DTB warns that herbal medicines can interfere with other medicinal products and prescription drugs and some herbal medicines may also worsen the symptoms of other underlying conditions.
It says extensive use of nettle, for example, can interfere with drugs used to treat diabetes, while willow bark can spark digestive symptoms and renal problems. Nettle and cat’s claw should not be used in pregnancy.