ABOUT THE GAIT STUDY

There are two phases of the research: the main, short-term study of six months that has and a longer-term one. In the latter, half the volunteers will continue their treatments for a further 18 months.

The study was funded by the National Institutes of Health (NIH), in Bethesda, Maryland - the primary US Federal agency for conducting and supporting medical research. It involves thirteen research centres across the United States and is co-ordinated by the University of Utah in Salt Lake City.

The study was a six-month, double-blind, five-arm, placebo-controlled trial that involved 1,258 patients with mild to severe osteoarthritis.

Over the trial period, every day patients were given one of either glucosamine (1,500mg); chondroitin (1,200mg); glucosamine and chondroitin combined; celecoxib (200mg); or placebo.

Findings of the GAIT Study

The patients who benefited most in the GAIT study were those with the highest knee pain scores at the beginning of the trial. Of patients with moderate-to-severe OA knee pain, 79.2 per cent on the glucosamine/chondroitin combination experienced pain relief compared with just 69.4 per cent of those taking celecoxib; and only 54.3 per cent of those taking placebo;

Of patients in the study with mild OA knee pain, the benefits were less marked. 62.9 per cent responded to glucosamine and chondroitin compared with 61.7 per cent responding to placebo;

Conclusions

Exploratory analyses suggest that the combination of glucosamine and chondroitinsulfate may be effective in the subgroup of patients with moderate-to-severeknee pain. Abstract of the GAIT study.

Comments

While pharmaceutical medication for OA with NSAIDs reduces pain, it does nothing to enhance joint repair or reverse joint degeneration. This is not the case with OA patients receiving glucosamine and chondroitin according to reports from users and their healthcare advisers who have observed that not only was the progression of the disease halted, it was reversed. The completion of the second phase of the GAIT study in two years' time should provide scientific support for these clinical observations.

In the meantime, the safety profile and mode of action of glucosamine and chondroitin suggest that they may help others at risk of osteoarthritis, such as athletes and people already experiencing some joint discomfort, as well as those already suffering.

The findings of this American trial together with the results of the European GUIDE study (www.guidetrial.co.uk), which compared the effects of glucosamine sulfate with acetaminophen (paracetamol) and a placebo on 318 patients with knee OA, make a very strong case for supplementation. The researchers chose acetaminophen for the GUIDE study because it is usually the first medication recommended for treating OA pain.

OSTEOARTHRITIS

Osteoarthritis is a disease that affects the joints. The surface of the joint is damaged and the surrounding bone grows thicker. When a joint develops osteoarthritis, the cartilage gradually roughens and becomes thin and the hone underneath thickens. The bone at the eds of the joint grows outwards, the synovium (a thin, layer of tissue which lines the joint space) swells slightly and may produce extra fluid. The joint capsule and ligaments slowly thicken and contract and muscles may weaken and become wasted.

In the past, OA was often referred to as “wear and tear” arthritis and considered irreversible due to progressive wearing-out of the joint. New research challenges that thinking. It is now known that, at least in the early stages of OA, the cartilage cells in the joint are very active, with repair mechanisms operating against destructive breakdown. These repair mechanisms could account for reports of people in whom OA has halted or even reversed. However, if the repair cannot compensate for the damage, osteoarthritis may seriously affect the joint, making in painful, stiff and difficult to move.

Causes

Research funded by the Arthritis Research Campaign (www.arc.org.uk) has identified that multiple genes play a major part in the development of osteoarthritis of the knee in a study of 1,200 UK patients published in the February 2006 issue of Arthritis & Rheumatism. This research demonstrates that osteoarthritis has a genetic cause in addition to risk factors already known such as ageing, previous cartilage damage, overweight and under- or over-use.

GLUCOSAMINE & CHONDROITIN

Glucosamine

Glucosamine is a form of amino sugar found naturally in the body where it has a vital role in cartilage formation and repair.

Glucosamine is a major building block of proteoglycans and is needed to make glycosaminoglycans (GAGs) proteins that bind water in the cartilage matrix. Each person produces a certain amount of glucosamine but age affects the body's ability to produce enough.

An insufficient supply of glucosamine restricts the efficiency of cartilage rebuilding and can delay repair of cartilage and other connective tissues. Regular intake of glucosamine (orally or by injection) has been shown to slow OA progression by halting joint space narrowing and so maintain the health and mobility of the affected joints. It cannot easily be obtained from the diet as it is found in only a small number of foods. Glucosamine supplements are derived from the shells of shellfish like crab, lobster or shrimp.

Chondroitin

Chondroitin is naturally present in cartilage and connective tissue and is involved in the attraction of fluid that lubricates the joints. Like glucosamine, chondroitin is a building block of proteoglycans (one of the main structural components of cartilage).

Oral administration of chondroitin also prompts a significant increase in hyaluronic acid, a major component of synovial fluid which is the lubricating fluid in joints. Like glucosamine, chondroitin is a natural amino sugar already present in the body, but not always in sufficient quantity for joint health and repair. Chondroitin supplements are sourced from shark or animal cartilage.

Supplementary Supplements

One other supplement that nutritionists and rheumatologists agree can help ease arthritis pain and joint stiffness is cod liver oil. The omega-3 fatty acids in cod liver oil have recognised anti-inflammatory properties (the word arthritis comes from the Greek arthro meaning ‘joint’ and itis meaning ‘inflammation’) that bring relief from OA by easing pain and improving mobility. Additionally, research from Cardiff University ( ref,…………) has shown that regular intake on fish and/or cod liver oil can halt, even reverse, cartilage degradation.

Each of the three supplements: glucosamine, chondroitin and cod liver oil; has a different mode of action on joint health and repair but together they have a synergy that suggests superior patient benefits from taking all three. There are no known adverse interactions.