Glucosamine is the most popular supplement taken worldwide, first prepared in 1876 by Georg Ledderhose but not commercially available until 1939. It was initially manufactured by processing chitin from the shells of shellfish. Today, it’s also made from the tracheal cartilage of cattle used otherwise for food; reputable manufacturers make sure this is taken from cattle that have not received growth hormone. For vegetarians, it can also be manufactured from the fungus Aspergillus niger and from fermenting corn.
Glucosamine is an amino sugar. Amino sugars are formed in the body from glucose and an amino acid; in the case of N-acetyl-glucosamine (NAG), the amino acid is glutamine. These amino sugars bind together to form long polysaccharide chains called glycosaminoglycans (GAGs), which include glucosamine and chondroitin. They then combine with fibrous proteins such as collagen to form the extracellular matrix in the human body: the meshwork of tissue that holds cells (and therefore the body) together.
Therapeutic uses
Osteoarthritis
Idiopathic osteoarthritis is the most common form of osteoarthritis worldwide and remains the leading cause of disability with an associated socioeconomic burden in an increasingly ageing population. GAGs are a major component of cartilage (and ligaments), so supplementing with glucosamine provides the specific nutrients for the repair of these tissues while reducing the inflammation and therefore alleviating osteoarthritis.
Glucosamine is sold in various forms as sulphate, hydrochloride and NAG but the sulphur form appears to be the most effective for arthritis, sulphur being a critical nutrient in cartilage tissue.
Cancer: angiogenesis inhibition
Glucosamine (particularly as NAG) has been shown to reduce the risk of cancer metastases through angiogenesis. Early-stage cancer cells parasitise nutrients from surrounding tissue but before they metastasise, they have to grow new blood vessels (angiogenesis) to supply them with enough nutrients. So angiogenesis inhibitors, by reducing the growth of these, in effect starve the growing cancer cells and reduce the risk of spread. This is more effective for solid tumours. Research has shown glucosamine’s potential usefulness in breast and prostate cancer. In breast cancer, it downregulates glucose metabolism that supports cancer growth and is associated with decreased cell cycle progression and increased expression of the cell cycle inhibitors, thereby inhibiting the reproduction of cancer cells. In prostate cancer, NAG has been shown to reduce angiogenesis and invasion, thus reducing the risk of metastases.
Anti-inflammatory
Inflammatory cytokines have been implicated in the pathogenesis and progression of osteoarthritis and are the major cause of pain. Glucosamine has been shown to dramatically decrease the number of inflammatory cytokines responsible for the pain of arthritis.
Repair of gut membrane and microbiota
NAG is vita