Glucosamine as a means of joint protection

Author: Frédéric Delavier and Michel Gundill: Chapter from the book "Sports Supplements for Athletes".
2011-10-27

What is Glucosamine?

Glucosamine sulfate serves as a precursor to glycosaminoglycans, the second substance, after collagen, that is part of cartilage, ligaments, and tendons. The human body produces its own glucosamine from sugar and glutamine. The arguments for additional glucosamine intake are based on the fact that our body produces it in amounts that are insufficient to meet the increasing endogenous needs when the joints are injured due to intense training.

Mechanism of Action of Glucosamine

In vitro, glucosamine can stimulate the regeneration of joint cartilage and prevent its destruction. Thus, it could help in the production of hyaluronic acid—an important lubricant and "food" for joints. In medical practice, glucosamine is primarily used for the treatment of arthritis (inflammation of the joints).

Scientific Evaluation of Glucosamine's Effectiveness

N. Poolsup (2005) concluded that glucosamine slows the progression of arthritis, alleviates the associated pain, and improves joint mobility.

In one study, researchers compared the effectiveness of a daily single dose of glucosamine at 1500 milligrams against a placebo. This study lasted three years and included over 200 patients suffering from arthritis (J. Reginster, 2001). Thanks to glucosamine supplementation, subjective pain and mobility parameters improved by 24%, while participants receiving the placebo reported a 9% worsening. The joint space (cartilage thickness) decreased by an average of 0.31 millimeters in the placebo group, while it remained unchanged in the glucosamine group. In the placebo group, 30% of subjects experienced a narrowing of the joint space, classified as significant (over 0.5 millimeters). These differences indicate an effective impact of glucosamine on cartilage.

Additionally, researchers studied how effective glucosamine is for so-called "back pain" (L. Tant, 2006). Sedentary individuals suffering from back pain received glucosamine for 12 weeks. 8 out of 17 subjects reported improved health status.

However, not all studies have found glucosamine to be effective. Such contradictory effects are likely explained by the fact that when taken orally, the accumulation level of glucosamine in the joints increases very slowly (B. Biggee, 2006). Despite the body absorbing about 90%, only 0.4% of the total dosage reaches the joint.

To alleviate this issue somewhat, glucosamine-based ointments can be used. Over 8 weeks, patients suffering from knee arthritis applied either an ointment consisting of glucosamine, chondroitin, and camphor, or a placebo (M. Cohen, 2003). The group using the ointment with active ingredients reported reduced pain compared to the placebo group.

Therefore, it is more effective to use both glucosamine and chondroitin simultaneously. For instance, you can buy a supplement that contains a ready-made mixture of chondroitin and glucosamine, such as Joint Formula by Dobromil Fit, or a similar product.