Chrondroitin sulfate is as good as a common anti-inflammatory drug for knee osteoarthritis, according to a new European study.

The findings have been published online in the Annals of the Rheumatic Diseases and the researchers are suggesting that chrondroitin sulfate is considered as a treatment, especially for older people.

Previous studies for the supplement have shown mixed results. Some have found it does have some benefit for people with osteoarthritis whilst other results have been less promising.

What Is Chondroitin Sulfate?

Chondroitin occurs naturally in the connective tissues of people and animals.

Often sold as a dietary supplement, chondroitin sulfate usually comes from animal or marine cartilage.

It is popular, often combined with the supplement glucosamine, as a treatment for the pain of osteoarthritis.

Osteoarthritis

Osteoarthritis is the most common form of arthritis, affecting around 8.5 million people in the UK. It is a degenerative joint condition causing pain, loss of function, and often some degree of disability.

There is no cure for arthritis but it is usually treated with painkillers like paracetamol and non-steroidal anti-inflammatory drugs ( NSAIDs). However, these are not suitable for everyone and regularly taking high doses of paracetamol or NSAIDs can be associated with side effects.

The research team was, therefore, looking for effective and safe alternatives.

The Study

They carried out a clinical trial in which 604 patients with knee arthritis, from 5 European countries were randomly assigned to 1 of 3 daily treatments involving chondroitin sulfate, the NSAID celecoxib, and placebo pills.

Chondroitin sulfate is available as an over the counter supplement but the level of active ingredient can vary. So for the study highly purified, pharmaceutical grade, chondroitin sulfate was used.

Pain, joint function and overall acceptability to the patients were assessed over 6 months.

Findings

The results showed that knee pain and joint function improved significantly with all 3 treatments by day 30 (1 month), and this effect persisted over the 6 months.

However, the reductions in pain and improvements in joint function were significantly greater after 3 and 6 months in patients treated with either chondroitin sulfate or celecoxib.

Joint function improved more quickly in patients taking celecoxib, but there were no overall differences in the effectiveness of either active treatment.

Conclusions

The researchers conclude that high quality (pharmaceutical grade) chondroitin sulfate is as good as the widely prescribed NSAID celecoxib for the treatment of painful knee osteoarthritis.

They believe, in light of the known clinical risks associated with long-term use of NSAIDS and paracetamol, that chondroitin sulfate should be considered as a first-line treatment for knee osteoarthritis.

Cautions

The Arthritis Foundation on its website warns that some chondroitin tablets may contain high levels of manganese, which could be problematic with long-term use. It says if you are allergic to sulfonamides, you should start with a low dose of chondroitin sulfate and watch for any side effects.

Side effects include diarrhoea, constipation and abdominal pain.

Arthritis Research UK says if you take anticoagulants, you should only take chondroitin under your doctor’s supervision because it might increase the risk of bleeding. It also says you should be cautious about taking chondroitin if you have asthma because it might make breathing problems worse.

Supplements like chondroitin can be pricey and aren't routinely available on the NHS.

The latest research was sponsored by a pharmaceutical company marketing chondroitin sulfate.

Reaction

Reacting to the study findings in an emailed statement, Dr Natalie Carter, head of research liaison and evaluation at Arthritis Research UK, says: "Osteoarthritis affects 8.5 million people in the UK causing everyday pain and stiffness. It can make simple tasks such as climbing the stairs, dressing and getting to work difficult.

"This clinical trial improves our understanding of the effectiveness of chondrotin sulfate but, it is important to note that the NSAID offered quicker improvement in joint function. If you are struggling with pain we suggest you speak to your doctor, who can discuss all your treatment options with you. These include NSAIDs, paracetamol, exercise or physiotherapy. This way you can decide which is the best option for you, taking into consideration the risk of side effects."

SOURCES:

Annals of the Rheumatic Diseases

Pharmaceutical-grade chondroitin sulfate is as effective as celecoxib and superior to placebo in symptomatic knee osteoarthritis: the ChONdroitin versus CElecoxib versus Placebo Trial (CONCEPT)

Laboratory of the Government Chemist

Arthritis Foundation

British National Formulary

NHS Choices

Arthritis Research UK