Chondroitin & Glucosamine
Glucosamine and chondroitin are important components of cartilage, the tissue that protects the joints. Both glucosamine and chondroitin are naturally occurring substances produced by the body. Glucosamine and chondroitin are often used as dietary supplements to support the joints.
Glucosamine acts as a mild anti-inflammatory. Additionally, it is necessary for the joints to produce components of cartilage.
Chondroitin is an important basic component of cartilage. Chondroitin contributes to water retention – the retention of moisture – and the elasticity of cartilage, allowing the cartilage to optimally absorb shocks and the tissues surrounding the cartilage to be optimally nourished. Chondroitin, like glucosamine, which is often given in combination, may also help reduce the production of substances that cause inflammation, as inflammation in a joint is destructive to the joint.
The joint
Normally, the two bones of a joint, for example, the femoral head and the acetabulum of the hip joint, fit together precisely. To protect the bones from damage, their ends are covered with a smooth layer of cartilage – an elastic form of connective tissue that can withstand high pressure. The bones are held together by a joint capsule. The inside of this joint capsule contains the synovial membrane – a soft tissue that lines the inside of the joint capsule. This synovial membrane secretes a fluid: the synovial fluid. This fluid ensures the joint remains flexible and provides the cartilage with the necessary nutrients.
Joint problems
As animals age, or when osteoarthritis or other joint problems occur, the cartilage becomes less smooth and wears down. When this happens, the bones can no longer move smoothly against each other. The resilience/elasticity of the cartilage also decreases, causing more pressure to be placed on the joint capsule. As a result, the joint capsule must absorb shocks and becomes more easily damaged. This can lead to inflammation in the joints. Due to inflammation in the joint, the joint capsule produces less synovial fluid; less synovial fluid means the joints are less 'lubricated' and fewer nutrients are available for the cartilage.
In response to these problems, the bones of the joint may grow abnormally (to create a larger support surface). When the abnormally grown parts of the bone are under pressure, this causes pain.
In various joint problems, supplementation with glucosamine and chondroitin can provide support and potentially relieve pain.
Research
Medical studies in humans have shown that glucosamine contributes to the formation and repair of cartilage. Glucosamine also reduces inflammation and slows cartilage deterioration. Chondroitin improves the elasticity of cartilage and also reduces painful swelling in the joints. In dogs, research has shown that glucosamine can reduce pain in animals with osteoarthritis.
The intake of glucosamine and chondroitin combined may reduce joint pain and improve mobility. It may also have a positive effect on cartilage metabolism, and both substances have anti-inflammatory effects. Long-term treatment with these nutrients could even alter the progression of osteoarthritis.
Furthermore, administration of glucosamine through the diet contributes to collagen synthesis.
Other research has shown that supplementation with glucosamine and chondroitin can relieve arthritis-related symptoms.
Various studies have demonstrated that adding glucosamine and chondroitin to the diet shows a significant difference regarding pain, weight-bearing, and overall condition in dogs with osteoarthritis. These substances may also reduce subjectively assessed pain, which occurs after about 90 days. The effect of the nutrients was highest after 150 days.
In a study with 32 adult dogs of various breeds, preventive treatment with glucosamine hydrochloride and chondroitin sulfate was shown to reduce various symptoms in induced synovitis – inflammation of the joint lining, the synovial membrane. Dogs receiving preventive treatment with glucosamine and chondroitin showed less scintigraphic activity – a scintigraphy is a test using a radioactive substance to examine skeletal disorders – in the soft tissue phase. Their lameness scores were also significantly lower.
It is important to administer glucosamine and chondroitin together because the substances have a synergistic effect, meaning they enhance each other's effectiveness when given in combination.
