These are two supplements that have been making headlines the last few years because of their effectiveness in treating arthritis. Patients have noticed pain easing within two weeks after initially taking the substances; and, within six months, they are almost back to full use of the joint.Doctors in Europe and Asia have been using glucosamine and chondroitin sulfates for many years to treat osteoarthritis, but only a few western doctors are just now recognizing their benefits.
Referring to the pathophysiology of osteoarthritis, we can readily see why these supplements are so effective. Glucosamine and chondroitin sufates are major building blocks of the water-loving proteoglycans which branch off from the side of the cartilage and collagen fibers to increase its volume and ability to hold water.
Glucosamine has been shown to be the key factor in determining how many proteoglycans are produced by the chondrocytes. This may normalize cartilage metabolism and help to prevent its breakdown. If there is a high glucosamine content, more proteoglycans will be produced and more water will be held in place. However, if only a little glucosamine is available, fewer proteglycans will be made and less water will be attracted to the area.
Structurally, glucosamine is a molecule composed of glucose and amine which the body uses to make substances known as glycosaminoglycans (GAGs), necessary to bind water in the cartilage matrix.
As far as joints are concerned, the most important GAG is hyaluronic acid (HA), which forms an essential part of the matrix ‘glue’ that binds articular joint cartilage together.
HA attracts water and gives it structure, but it is also a critical component of the lubricating synovial fluid. HA and the proteoglycans not only hold water, but they also attract minerals, vitamins, and other nutrients that maintain the integrity of cartilage.
As we age, we lose the ability to synthesize sufficient levels of HA; and, what is manufactured, is smaller in size and less structurally effective. This results in a loss of strength, resilience, flexibility, and shock absorption within the joint. Glucosamine has been shown to slow this process while helping to repair and rebuild cartilage.
Because glucosamine stimulates the production of key elements of the cartilage matrix and then protects it, it can actually help the body to repair damaged or eroded cartilage.
Studies have shown that, besides stimulating the production of cartilage, glucosamine helps to reduce pain and improve joint function in those with osteoarthritis.
Another important fact is that it does not seem to matter if the glucosamine is manufactured in the body or comes by way of a supplement. Glucosamine supplements are available in four forms – hydrochloride, hydroiodide, n-acetyl, and sulfate. In European research, it is the sulfate form that is the most commonly used but it is the hydrochloride form that absorbs the easiest. Those with thyroid abnormalities should avoid the hydroiodide form.
Alone, glucosamine can relieve arthritis symptoms and restore cartilage health; but its effects are further enhanced when taken with chondroitin sulfate. Since glucosamine helps to form the proteoglycans that sit within the spaces in the cartilage netting, it is the chondroitin sulfates that act as water magnets.
As a long chain of repeating sugars, chondroitin helps attract fluid into the proteoglycan molecules, which act as shock absorbers, and helps sweep nutrients into the cartilage. Articular cartilage has no blood supply; therefore, all of its nourishment and lubrication comes from the liquid that ebbs and flows as pressure to the joint is applied and released. Without this fluid, cartilage becomes malnourished, resulting in its being drier, thinner, and more fragile.
Chondroitin, through its sulfate chains, ensures that the proteoglycans will attract and hold water in the cartilage.
To understand how this works, imagine a tall, strong tree trunk. This is like the backbone of the proteoglycan molecule. The large branches of the tree are the core proteins, and the smaller branches are like the chondoitin sulfate chains. These chains have negative electrical charges, which means they repel each other; but, like putting two magnets together, they align with the opposite pole.
The negative charges of the chondroitin work in a similar manner. By pushing chondroitins apart, they create a space that forms the matrix of the cartilage. There may be as many as 10,000 of these chains in just a single proteoglycan molecule, making it a super water retainer.
Besides drawing in precious fluids, chondroitin sulfates also protects existing cartilage from premature breakdown by inhibiting the action of certain destructive enzymes. It also interferes with other enzymes that attempt to starve cartilage by cutting off the transport of nutrients.
In addition, chondroitin sulfates stimulate the production of proteoglycans, glycosaminoglycans, and collagen. Although both work well alone, chondroitin works synergistically with glucosamine to increase dramatically the benefits; and, best of all, long term studies have found that people taking high daily doses have suffered no ill-effects.
Unlike glucosamine sulfate, where the absorption is excellent (90%-95%), the absorption of chondroitin sulfate is limited to between 8% and 13%. The difference in absorption rates is caused by the size of the molecules. Chondroitin sulfate is simply too large to pass through the normal gastro-intestinal wall. If, by chance, a smaller molecule of chondroitin sulfate did pass through, it would still be too large to be delivered to the chondrocytes (cartilage cells).
Despite this fact, clinical studies have shown that the compound does have a positive effect on arthritis and does boost the effectiveness of glucosamine sulfate. Other studies indicate that chondroitin increases HA and its effects have lasted for three years longer than using glucosamine alone.
It has also been suggested that glucosamine may induce insulin resistance, promoting the development of diabetes and obesity when used for a long time. This theory was based on studies which used IV glucosamine given to rats and does not appear to apply to humans taking oral supplements. Studies that have been done on humans indicate that the blood sugar levels have remained normal or slightly lower than those control subjects taking a placebo.
In addition to having benefits for those with osteoarthritis, glucosamine can be helpful for asthma, bursitis, candidiasis, food allergies, osteoporosis, respiratory allergies, tendinitis, vaginitis, and various skin problems.
In order to qualify as a truly chondro-protective agent, a compound must be able to do the following:
- Enhance cartilage cell macromolecule synthesis (glycosaminoglycans, proteoglycans, collagens, proteins, RNA, and DNA);
- Enhance the synthesis of hyaluronan (the substance that gives the joint fluid its thick viscosity providing lubrication between the synovial membrane and cartilage);
- Inhibit the enzymes that degrade the cartilage cell macromolecules;
- Mobilize thrombi, fibrin, lipids, cholesterol deposits in synovial spaces, and blood vessels in surrounding joints;
- Reduce joint pain;
- Reduce synovitis (inflammation of the synovium).
No drug or supplement acting alone can do all this. However, glucosamine and chondroitin can if they work together. Clinical studies show that glucosamine can accomplish objectives 1,2,5, and 6 while chondroitin handles 1,3,4,5, and 6. Their overlapping abilities explain why the glucosamine and chondroitin combination is such a powerful treatment for osteoarthritis.
Dosages are usually calculated according to body weight, although some individuals require more and some less. The dosages should be divided into equal amounts two to four times a day.
The basis is as follows:
- If the body weight is less than 54.5 kg (120 pounds), take 1,000 mg glucosamine and 800 mg chondroitin.
- if the body weight is between 54.5 and 91 kg (120 and 200 pounds), take 1,500 mg glucosamine and 1,200 mg chondroitin.
- if the body weight is more than 91 kg (200 pounds), take 2,000 mg glucosamine and 1,600 mg chondroitin.
Note: Vitamin B6 (along with a B-complex) is needed to help with the absorption of glucosamine and chondroitin sulfates. The suggested dosage is 50 mg. three times a day or with each supplemental intake of the substances.
Warning: Chondroitin sulfate should NOT be taken by those with prostate cancer or those at risk of other cancers. Research has shown that chondroitin sulfate attaches to two proteins in prostate tissue: decorin and versican. Decorin suppresses the ability of cancer to spread while versican tends to increase the spread. Five years after prostate cancer surgery, scientists found that 89% of the men with high versican levels had their cancer recur compared with 27% who had low levels. Versican can also be found on a wide range of cancer cell types including melanoma and some brain tumors. Therefore, those at risk for any cancers should not take chondroitin at all. However, it has been proven that glucosamine sulfate poses no risk in the progression of any cancers; instead, it does preserve the thickness of joint cartilage.