Science of joint health ingredients ‘inconclusive’, says review
According to a new review in the International Journal of Rheumatic Diseases, “several osteoarthritis supplements in combined preparation and appropriate dosage could play a role among certain groups of osteoarthritis patients in the reduction of moderate to severe pain”.
But the evidence for many is “inconclusive”, write Evan Vista from the Joint & Bone Center at the University of Santo Tomas Hospital in the Philippines, and Chak Lau from the Division of Rheumatology and Clinical Immunology at The University of Hong Kong.
In order to explore the full potential of such supplements, clinical trial design should be uniform and international regulatory bodies should strive for a “stringent approach and consensus”, added the reviewers.
Joint health burden
As populations age, the burden of osteoarthritis is growing. Over 20 million Americans suffer from osteoarthritis, and this is reported to be second only to ischemic heart disease as a cause of work disability in men over 50.
According to the Center for Disease Control, the direct and indirect costs are estimated to be approaching $90 billion. Elsewhere, the figures are equally worrying, with approximately seven million people in the UK alone are reported to have long-term health problems associated with arthritis.
Pharmaceutical solutions include non-steroidal anti-inflammatory drugs (NSAIDs), which are seen by many as daily necessity to control pain and allow people to carry out their everyday activities.
Some NSAIDs, which are among the most frequently prescribed medications worldwide, have been linked with gastrointestinal toxicity, increased blood pressure, and increased risk of cardiovascular disease.
Glucosamine
The market for dietary supplements promoting joint health is dominated by glucosamine and chondroitin sulfate. Amongst the most important studies supporting the apparent benefits of the ingredients was the $14 million Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), sponsored by the National Institute of Health, which studied the effects of the supplements in 1583 people with osteoarthritis
The results, published in the prestigious New England Journal of Medicine (2006, Vol. 354, pp. 795-808), indicated that the combination of glucosamine and chondroitin sulfate “significantly decreased” knee pain for people suffering from moderate-to-severe osteoarthritis.
According to the new review, these supplements work by offering anti-inflammatory effects that influence the breakdown of cartilage in the joints. When combined together, glucosamine and chondroitin have been shown to “act synergistically to modulate articular cartilage matrix metabolism”.
But the reviewers were unconvinced by the totality of the evidence.
“Prevention of articular cartilage degradation, the main pathology change of OA, has not been addressed satisfactorily by the present conventional treatments available for this condition,” wrote Vista and Lau.
“The minimal therapeutic efficacy of these drugs is further aggravated by the inherent toxicity demonstrated by their long-term use.”
Other options
In addition to glucosamine/chondroitin, the reviewers also note omega-3 fatty acids, S-adenosylmethionine (SAMe), and methylsulfonylmethane (MSM), as dietary supplement ingredients worth considering.
According to Vista and Lau, data exists which shows that SAMe may equal NSAIDs for short-term pain relief but with few side effects, while a meta-analysis with MSM produced “inconclusive” results.
Bone & joint health
This topic, and others, will be covered in the upcoming Bone & Joint Health virtual conference, hosted by NutraIngredients-USA.com. The free event will feature speakers from GNC, Miami Research Associates, and Leatherhead Food Research. For more information and to register, please click here.
Source: International Journal of Rheumatic Diseases
2011, Volume 14, Pages 152-158
“What about supplements for osteoarthritis? A critical and evidenced-based review”
Authors: E.S. Vista, C.S. Lau
