Arthritis is a growing health problem and a common cause of disability in many industrialized countries, including the United States. It is estimated that nearly 80 percent of Americans 50 years and older show some signs of joint destruction on x-rays, including cartilage erosion and bone disfigurement. One factor in excessive "wear and tear" of joints is thought to be an age-related decline in the natural synthesis of glucosamine, which contributes to joint lubrication and cartilage formation. Different forms of glucosamine are marketed as supplements, each displaying different properties.
Glucosamine is a naturally-produced substance within joint capsules in virtually all animals. Specifically, chondrocyte cells synthesize glucosamine wherever there is cartilage, because the byproducts of glucosamine are combined with collagen to produce and repair cartilage. Healthy cartilage is relatively flexible and spongy in composition, which is essential for absorbing the forces within weight-bearing joints. Glucosamine also contributes to the slippery consistency of the liquid within most joints, called synovial fluid, which acts as lubrication. Thus, reduced production of glucosamine, which becomes significant near the age of 50, leads to stiff, condensed cartilage and reduced viscosity in synovial fluid.
Supplemental Glucosamine Sulfate
Glucosamine sulfate stabilized with sodium chloride is the most prevalent form of glucosamine on the market and the one most studied in human and animal trials. Numerous studies have found this variety of glucosamine effective at reducing pain and inflammation, while increasing mobility in mild-to-moderate cases of osteoarthritis, especially of large weight-bearing joints such as the knee and the glenofemoral joint of the hip, according to MedlinePlus. Its impact on other forms of arthritis, such as rheumatoid arthritis, is less pronounced. Glucosamine sulfate is also stabilized with potassium chloride, although it has not been studied in clinical trials and is not commonly sold as a supplement. Both sulfate forms of glucosamine are often derived from shellfish, such as shrimp and crab, so be cautious if you have allergies.
Supplemental Glucosamine Hydrochloride
Glucosamine is also combined with hydrogen chloride, HCl, and made into a supplement. Glucosamine HCl supposedly contains slightly more organic glucosamine within its structure and is more stable within the body, but it has not performed as well as glucosamine sulfate in scientific studies as cited in "Nutritional Sciences." Some researchers claim that the quality or dosage of the glucosamine HCl affected the results of the studies, while others point to the need of sulfur's presence for cartilage production and maintenance to occur efficiently. Regardless, some manufacturers utilize vegetable sources to attain glucosamine HCl instead of grinding up the exoskeletons of shellfish, which greatly reduces the concerns of contamination and allergic reactions. As such, glucosamine HCl is the safer supplement with far fewer side effects but has not outperformed sulfate varieties in experiments. Future research may prove otherwise.
Dosages and Recommendations
The dosages considered effective at reducing the symptoms of osteoarthritis are the same for both glucosamine sulfate and hydrochloride, which is 1,500 milligrams daily, divided into three equal dosages, according to "The New Encyclopedia of Vitamins, Minerals, Supplements, and Herbs." Consequently, many glucosamine tablets are conveniently offered in 500 milligrams doses. Both types of glucosamine also come in liquid form and are sometimes combined with other natural pain and inflammation remedies, such as chondroitin, MSM, devil's claw and hyaluronic acid. Both forms can also lead to stomach upset, heartburn and diarrhea in some users.