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Two supplements for treating joint pain do not work, says a recent study but some users say otherwise
 Doctors and physical trainers say they will continue to prescribe glucosamine and chondroitin, two supplements for joint pain, despite what a recent study says.
The Swiss study, published in the British Medical Journal this month, concluded that the two supplements, taken by millions of people worldwide, do not work.
The supplements are commonly prescribed for mild to moderate osteoarthritis, or age-related wear and tear of the knee.
In Singapore, one in 10 people between the ages of 18 and 69 suffers from arthritis.
In a review of trials involving 3,803 patients with knee or hip osteoarthritis, the Swiss researchers found that there was “no clinically relevant effect” of chondroitin, glucosamine, or the two in combination, on perceived joint pain.
Glucosamine and chondroitin sulfate are components of glycosaminoglycans, the building blocks of joint cartilage.
Cartilage is the connective tissue in the joint between bones that allows for smooth gliding during movement. Once cartilage is lost or damaged, movement causes friction and joint pain.
The study reviewed 10 previously published trials and assessed data on changes in levels of pain after patients took glucosamine, chondroitin, or a combination, compared with a placebo.
It also noted that global sales of glucosamine supplements hit almost S$2 billion (S$2.66 billion) in 2008, an increase of about 60 per cent since 003.
In Singapore, they are available over the counter in most pharmacies. A ottle of 90 to 120 glucosamine sulfate tablets typically costs between $30 and 60.
A similar quantity of tablets that combine glucosamine and chondroitin s usually priced from $43 to $85. Asked to comment on the Swiss tudy, Dr Roger Tian, a sports physician with the Singapore Medical Group, notes that glucosamine may have a role in slowing down the loss of artilage in patients with mild to moderate osteoarthritis.
“What has been demonstrated in previous studies using magnetic resonance imaging to measure cartilage thickness, is that glucosamine in sulphate form may retard the loss of articular cartilage in the knee,” he says.
“However, it works in only 50 per cent of patients,” he notes, adding that he will continue to prescribe the supplement to the appropriate patients.
Personal trainer Chris Chew points out that previous studies have yielded different conclusions about the efficacy of glucosamine.
For example, a 2006 study of 1,600 patients published in the New England Journal Of Medicine found that the glucosamine-chondroitin combination may be an effective treatment for those with moderate to severe knee pain.
“The Swiss study is only one study and is not conclusive. I will still recommend it to my clients with joint pain until it is conclusively proven,” he says. “Besides, there is no side effect at all.”
Dr Melvyn Wong, a senior physician with Raffles Hospital, notes that studies are constantly being done to prove or disprove a theory.
“Professional and public opinion about a certain product or drug will change with time,” he says.
Other health professionals such as Dr Andrew Dutton, an orthopaedic surgeon with National University Hospital, says he will continue prescribing both supplements to arthritis patients but in a limited manner.
“I would counsel the patient to stop taking glucosamine if there’s no benefit after three months so that the patient also does not spend needlessly,” he says.
He also cautions athletes with joint pain against self-medicating with glucosamine. “The athlete may be suffering from a different or more serious underlying problem and may cause himself more harm by delaying appropriate treatment,” he warns. For civil servant Cheri Lim, 29, taking the supplements did help ward off joint pain.
She took glucosamine for four years to treat knee pain resulting from strenuous training to become a uniformed officer.
She ran at least 5km twice a day then. “The pain in both knees was so bad that I couldn’t even walk,” she recalls.
The supplements, prescribed by doctors, coupled with a less intense running regimen, saw the pain gradually going away.
Ms Lim, who now runs up to three times a week, adds: “It worked for me, and I also know people who take it a few months before a marathon, and they say it helps.”
For other consumers, their decision to use – or not use – the supplements could well rest on the results they get, never mind what the scientific studies may say.
Take the case of partnership manager Stacy Low, 29, who cycles three to four times a week, clocking between 60km and 100km each time.
She has taken glucosamine in the past three months to treat pain in her right knee, spending a few hundred dollars so far.
She decided to try out the supplement after doing research.
“I’m not sure if it’s effective as the pain in my knee is still present. After my current supply of glucosamine runs out, I will monitor my knee pain and decide whether to continue with it,” she says.
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