The joint cartilage is composed of collagen fibers, which impart tensile strength, and proteoglycan molecules (especially chondroitin and hyaluronic acid), which serve as a shock- absorbing cushion. The hands, as well as weight-bearing joints (knees, hips and spine), are areas that undergo the greatest stress from the impacting pressure of weight and movement. In order to maintain joint health, it is important that the collagen matrix, or the support structure of the cartilage, remains intact. Glucosamine is an aminomonosaccharide, which is a component of almost all human tissues, including cartilage. Glucosamine is the principal component of glycosaminoglycans (GAGs), which form the matrix of all connective tissues.
Joint Integrity and Movement†
Glucosamine sulfate’s main physiological effect is to stimulate the production of glycosaminoglycans and promote the incorporation of sulfur into the cartilage to maintain its gel-like structure and ability to act as a shock absorber. Glucosamine is the most fundamental building block for the biosynthesis of other compounds required to maintain joint health including glycolipids, glycoproteins, hyaluronate and proteoglycans. Meta-analyses have long confirmed positive findings for the use of glucosamine.2-4 In an early double-blind, placebocontrolled trial of 80 subjects, half of the group received 1.5 g of glucosamine sulfate in 3 divided doses, and the other half was given a placebo. Those given glucosamine sulfate demonstrated a significant improvement in maintaining joint health, versus the placebo group (71% vs 41%).5 A more recent 16-week, randomized, double-blind, placebo-controlled trial of a glucosamine-based dietary supplement with chondroitin sulfate and three antioxidant micronutrients, found that joint health was maintained at all four assessment time points (weeks 4, 8, 12 and 16) in the control group, but not at any time point in the placebo group.7 Lastly, a 2013 study of data from a French database of 11,772 adults found that those taking a glucosamine supplement were able to maintain joint health.7
Normal Inflammatory Balance†
Although exact mechanisms of action are yet to be established, research suggests that glucosamine supplementation helps modulate cytokine production in addition to directly stimulating chondrocytes (cartilage cells that help produce and maintain a healthy cartilage matrix), while aiding in the incorporation of sulfur into cartilage.8,9 Glucosamine has been found to maintain normal inflammatory balance and alleviate oxidative stress.11