Health news - Diet supplements may help to reduce osteoarthritic knee pain
3 March 2006 - written by Michael Paterson for Bupa's health information team
Two popular dietary supplements, glucosamine and chondroitin sulphate, may relieve moderate to severe osteoarthritic knee pain, according to a study published in the New England Journal of Medicine.1
How was the study carried out?
Researchers in the USA tested around 1600 people who had osteoarthritis that affected their knees.1 At the start of the study, 78 percent of the participants suffered from mild knee pain. The remaining 22 percent suffered from moderate to severe knee pain. Over a 24-week period, each patient was given either a placebo ('dummy') pill, celecoxib, glucosamine, chondroitin sulphate, or a combination of glucosamine and chondroitin sulphate.
What did the study show?
8 in 10 people who had moderate to severe knee pain before the trial started experienced significant pain relief when they took both supplements (glucosamine and chondroitin sulphate) together. This is compared to almost 7 in 10 people who took celecoxib and 5 in 10 people who took the placebo. Those patients who took only one supplement reported a similar drop in pain to those who took the placebo.1 However, glucosamine and chondroitin sulphate proved no better than a placebo in relieving mild knee pain.
What did the researchers suggest?
Further tests might prove beyond doubt that the supplements could reduce moderate to severe knee pain.1 In the meantime, the researchers urged people with osteoarthritis to develop and maintain a healthy lifestyle, and consider their use of medications based on their degree of pain.
How do the two supplements work?
Glucosamine is an amino acid that is naturally produced by the body. It is an essential building block of bone, blood vessels, joints and ligaments.2 Chondroitin sulphate is a complex carbohydrate that helps to make healthy joint tissue.2
Taken by mouth, these substances may work together to help the body to make new joint cartilage and to repair damaged cartilage.2 Other tests have suggested that glucosamine may reduce stiffness and pain in joints when used on its own.
What is arthritis?
Arthritis is a general term for a number of painful conditions of the joints and bones.3 It means 'inflammation of the joints'.
What is osteoarthritis?
Osteoarthritis is the most common form of arthritis. Cartilage between the bones gradually wears away and can cause painful rubbing of bones in the joints. It may cause joints to fall out of their natural positions. The most frequently affected joints are in the hands, spine, knees and hips.3
Who gets osteoarthritis?
Osteoarthritis mostly affects people aged between 40 and 60. It's more common with age. Around 12 in 100 people over 65 are affected.3
What causes it?
The cause is unknown. It might be partly passed down through generations.4 Factors known to make its onset more likely include:
- a physical injury to the joint
- being very overweight
- over-use of joints
- infection
- damage to the nerve supply to a joint
- other conditions which change the position of bone ends (such as rickets, bow-legs and knock-knees)
- other joint diseases (such as gout or rheumatoid arthritis)
What are the symptoms?
First signs include occasional pain and stiffness in the joints, with pain becoming more frequent. Moving the joint becomes increasingly difficult, particularly when the joint thickens. This can cause a creaking sound. Even minor injuries can cause swelling. Muscles that normally move the joint may get tighter and shorter and stop the joint from going straight, unless the condition is treated.4
What about conventional treatments?
There is no cure for the condition. But treatments include:
- taking paracetamol
- rubbing anti-inflammatory creams and gels into the joints
- taking anti-inflammatory painkillers like ibuprofen (eg Nurofen) and naproxen (eg Naprosyn)
- injections into the fluid of the joint
- having an osteotomy (an operation to remove a piece of bone from the knee join).6
- having knee-replacement surgery
- having hip-replacement surgery
What lifestyle changes can help oestoearthritis?
You can help control osteorthritis in the following ways:
- Be generally physically active. Doing aerobic exercise can improve your overall fitness. It helps your heart to pump blood around your body and helps your lungs to take in air. It can help you to lose weight and to feel good about yourself. Aerobic exercise should increase your heart rate. Try walking, swimming or cycling for 30 minutes, three times a week.
- Do knee exercises. The best exercises for the knee may be those that strengthen the muscle at the front of the thigh. Lie down on the floor and lift you leg straight up in the air and hold, then repeat. Your knee joint doesn't move, but you strengthen the muscles that support it.
- Use physical aids: There are lots of devices that can help, including shoe wedges and insoles, walking sticks, joint braces, splints and tapes.7
Bupa Information:
Bupa factsheet: Osteoarthritis
Further information:
Arthritis Research Campaign
0870 850 5000
www.arc.org.uk
Arthritis Care
0808 800 4050
www.arthritiscare.org.uk
References
- Clegg D, Reda D, Harris C, Klein M, O'Dell J, Hooper M et al. Glucosamine, Chondroitin Sulfate, and the Two in Combination for Painful Knee Osteoarthritis. The New England Journal of Medicine 2006 vol 354 no.8.
- Glucosamine and chondroitin. Best Treatments - clinical evidence for patients from the BMJ.
- Arthritis. NHS Direct Online Health Encyclopaedia.
- Osteoarthritis - Causes. NHS Direct Online Health Encyclopaedia.
- Osteoarthritis - Symptoms. NHS Direct Online Health Encyclopaedia.
- What Treatments Work For Osteoarthritis? Best Treatments - clinical evidence for patients from the BMJ.
- Exercise and Physiotherapy. Best Treatments - clinical evidence for patients from the BMJ.
www.besttreatments.co.uk
www.nhsdirect.nhs.uk
www.nhsdirect.nhs.uk
www.nhsdirect.nhs.uk
www.besttreatments.co.uk
www.besttreatments.co.uk
All pages were accessed on 27 February 2006.
