Glucosamine and Chondroitin

Glucosamine and chondroitin sulfate exist naturally in human and animal cartilage. They may help alleviate the pain and stiffness associated with osteoarthritis, one of the most common types of arthritis, in which the cartilage surrounding the joints deteriorates as a person ages, causing the bones to rub together. Unfortunately, there is no cure for this disease, but results of many clinical studies show promise in identifying glucosamine and chondroitin sulfate’s role in slowing the breakdown of cartilage and decreasing the pain and inflammation associated with osteoarthritis.

How these two compounds work is not fully understood, but some research shows that glucosamine, an amino sugar, may help to build and repair cartilage by producing more proteoglycan, a protein that gives cartilage its elasticity. Chondroitin sulfate, a component of proteoglycan, helps to maintain fluid levels within cartilage and may even inhibit the activity of enzymes responsible for breaking down cartilage. A study published in the Journal of the American Medical Association (February 2000) showed that glucosamine, treated with a radioactive dye allowing researchers to follow the compound through the subjects’ bodies, did indeed travel to the joints and incorporate itself into the cartilage to help stimulate new cartilage growth.

Another study published in the British Journal of Sport Medicine (January 2003) concluded that 88% of the participants with chronic knee pain who consumed 2,000 mg of glucosamine daily experienced a decrease in the pain compared with those participants who received a placebo.

Glucosamine, an odorless, white crystal powder, and chondroitin sulfate, a white, water-soluble powder, are dietary supplements according to the Dietary Supplement and Health and Education Act (DSHEA). Dietary supplements include vitamins, minerals, amino acids, herbs or botanicals. FDA does not regulate their safety or effectiveness; rather, the manufacturers manage the safety of the supplements. As a result, these two ingredients are not currently allowed in what the FDA defines as food products. According to DSHEA, if manufacturers can put these two supplements in a bar or other edible form, they must label the product as a dietary supplement and not as a conventional food.

Food manufacturers, however, recently applied to FDA to list glucosamine and chondroitin sulfate as GRAS for use in food and beverages. In the meantime, scientists continue to develop products that contain these two supplements and work to determine the proper usage levels for formulating with glucosamine and chondroitin sulfate.

Most clinical trials report that a daily dose of 1,200 mg of chondroitin sulfate produces sufficient results in relieving the pain of osteoarthritis. Other trials found that 1,500 mg of glucosamine for six to eight weeks, with a maintenance dose of 750 mg, are effective. Scientists use these levels, along with the target serving sizes of the products under development, in determining exactly how much supplement to use for specific applications, says Tim Bauer, director of sales of BioPolymer Products, Cargill Acidulants, Naperville, IL.

The effectiveness of glucosamine and chondroitin sulfate depends on a number of factors, including the amounts used, types, purity and quality. Scientists wanting to formulate products using glucosamine and chondroitin sulfate should deal with reputable suppliers to ensure receiving pure supplements free of as much contamination as possible.

As the costs of medications rise and frustrations mount against the administration and management of health care in the United States, many people are turning to dietary supplements and functional foods as a way to treat and prevent illnesses. According to a national poll conducted by Harris Interactive in 2001 for the Dietary Supplement Information Bureau, 59% of Americans take a dietary supplement on a regular basis, and 23% use herbal or specialty supplements. The poll also found that consumers take supplements to: help feel better (72%); help prevent getting sick (67%); get better once they are already sick (51%); live longer (50%); build strength and muscle (37%); and manage weight (12%).

Compounding these results is the fact that as more baby boomers enter their golden years, they experience degenerative diseases like osteoarthritis, leading food manufacturers to work on developing products, such as confections, nutritional bars and beverages containing glucosamine and chondroitin. “The growth in functional products has been estimated to be three to four times the growth of food products in general,” says Bauer, whose company is one of many working on the development of functional food products containing glucosamine and chondroitin sulfate.

Processors extract chondroitin sulfate from animal cartilage and glucosamine from shellfish. Because shellfish causes severe allergic reactions in some people, new methods that isolate glucosamine from other sources produce an alternative for broader consumption.

Glucosamine comes in two recommended forms: hydrochloride and sulfate. According to Bauer, Cargill uses a corn fermentation process to produce a shellfish-free, non-animal, kosher glucosamine product under HACCP conditions for those interested in a natural form. This product, he adds, is 83% glucosamine on an active basis, while the sulfate version is approximately 50% to 60% glucosamine on an active basis. Likewise, the company also produces a natural form of chondroitin from bovine cartilage using a water-based proprietary process that, says Ted Ziemann, president of Cargill Health & Food Technologies, Minneapolis, results in the first North American-sourced, solvent-free chondroitin sulfate with less than 10% moisture.

As with all supplements, product designers should be aware of any possible side effects. In addition to any allergenicity concerns, glucosamine may increase the risk of a person developing insulin resistance. Since glucosamine is a molecule derived from glucose, several animal studies have shown that it may raise blood sugar levels, which is of concern to people with diabetes.

Lastly, high dosages of either of these dietary supplements may irritate the stomach; however, studies that concluded this examined the effects of doses well in excess of the suggested effective usages levels.

Ziemann notes that the National Institute of Health Glucosamine/ Chondroitin Arthritis Intervention Trial (GAIT) is the first multicenter clinical trial in the United States to test the effects of chondroitin sulfate for the treatment, including pain reduction and improvement in functional ability of osteoarthritis of the knee, and that the report for the trial is due in March 2005. “At that time, scientists and consumers should have a better understanding of the effective dose range,” he adds.

As more information becomes available on glucosamine and chondroitin sulfate, companies work to determine the optimum levels of these compounds in new products that are both safe and effective in helping to prevent the pain of osteoarthritis.

Karen Banasiak is a freelance writer and food-industry consultant from Chicago. She has an M.A. in journalism from Michigan State University, East Lansing, and will receive an M.S. in food science from University of Illinois, Urbana, in the fall of 2003.

Back to top