Glucosamine 

Glucosamine is a molecule naturally present in the body, constituting connective tissue, cartilage and ligaments. It plays a crucial role in maintaining the integrity of cartilage and joints. It is also found in the shell of crustaceans.

 

• Definition of Glucosamine
• History of glucosamine
• What are the benefits?
• What are the daily needs?
• What happens in case of lack of glucosamine?
• Where to find glucosamine?

Glucosamine DefinitionGlucosamine DefinitionGlucosamine

Glucosamine is formed by the body from glucose and glutamine (Figure 1). It is part of the family of amino sugars and its molecular structure is close to glucose. It is a precursor of chondroitin sulphate and it is part of the composition of hyaluronic acid. It is a molecule present in many living organisms, mainly in the shells. In humans, it is found in the form of glucosamine-6-phosphate, in the cartilage matrix, but also in the skin, tendons and ligaments. The production of glucosamine in humans is between 4 and 20 g/day.

It thus plays a crucial role in maintaining the integrity of the cartilage of all the joints. When the glucosamine manufacturing process goes wrong, the cartilage breaks down and inflammatory phenomena such as arthritis and osteoarthritis can develop.

 

History of glucosamineHistory of glucosamine 1,2

Historically, the molecule was discovered and isolated for the first time in 1876 by the surgeon Georg Ledderhose, by hydrolyzing crustacean chitin. It was in 1969 that, for the first time, German doctors reported the clinical use of glucosamine in the management of certain joint pathologies.

At the end of the 1970s, an Italian firm developed glucosamine sulphate tablets, in order to facilitate the administration of this substance. This form is the one generally used in food supplements. It can also be found in the form of glucosamine hydrochloride, but this has shown no effect on the joints. N-acetylglucosamine is a glucosamine derivative that can also be used as an alternative to glucosamine sulfate.

 

Benefits of glucosamineWhat are the benefits of glucosamine 3,4

Unlike bone, which has significant healing properties, cartilage regenerates little and heals with difficulty. Cartilage has the characteristic of being neither innervated nor vascularized: the absence of nerves, and especially that of vessels, explains why it is difficult to repair itself in adulthood. However, our cartilaginous capital is fragile, subject to trauma and various inflammatory (arthritis) or degenerative (osteoarthritis) phenomena.5

Glucosamine is mainly known for soothing pain related to joint disorders and for its action in joint inflammatory phenomena. In the body, the main role of glucosamine is the synthesis of glycosaminoglycans, polymers of sulfated and amino sugars, which are key elements in the structure of cartilage. Glucosamine also has strong antioxidant power.

Glycosaminoglycans (GAGs) have a strong capacity for water retention. Glucosamine therefore helps to repair and regenerate joint cartilage. It helps to gradually reduce joint discomfort and improve mobility.

In many studies, taking glucosamine has been shown to help reduce discomfort and improve mobility in people with cartilage injuries6, speed up recovery in athletes with knee injuries7, or help with pain in patients with knee injuries. rheumatoid arthritis8. The majority of studies focus on its effects on reducing symptoms of osteoarthritis, including walking and joint pain.

Among the active ingredients to boost the absorption of glucosamine, chondroitin (otherwise known as chondroitin sulfate) is most often used. It is a glycosaminoglycan found in connective tissue, and also a component of the cartilage matrix. It protects it from oxidative damage caused by free radicals, and limits enzymatic destruction, while promoting reconstruction10.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for pain management in osteoarthritis, but long-term use is not recommended and may be poorly tolerated. One of the significant advantages of glucosamine is that it has few side effects, and helps maintain joint capital.

 

Glucosamine requirementWhat are the daily requirements?

The recommended amount should be less than the pharmacological dose (1500mg/d of glucosamine sulphate). At a dose of 1000 mg/d, several studies confirm the benefits of glucosamine. Its quantity can nevertheless be lower if it is combined with other active ingredients, such as chondroitin, which will allow a synergistic action.

 

Lack or excess of glucosamineWhat happens in the event of a lack of glucosamine? 2

An opinion from the National Food Safety Agency published in 2019 reports several interactions between glucosamine and glucose metabolism. The consumption of glucosamine-based food supplements should therefore be medically supervised in diabetics or prediabetics, asthmatics and people with a food allergy to shellfish, even if several studies12 indicate that glucosamine has no effect on sugar levels. and insulin resistance, within the recommended dosage window.

Generally glucosamine has no significant adverse effects, even at 3000 mg per day. However, an increase in the base dose (above 1500 mg per day) may lead to loose stools and, more rarely, gastrointestinal discomfort.

 

Where to find glucosamineWhere to find glucosamine?

Glucosamine is hard to find in common foods. In food supplements, glucosamine is present in the form of sulfate or hydrochloride. These forms are essentially prepared by hydrolysis of chitin, the main component of the shell of crustaceans such as crabs, shrimps and crayfish. The glucosamine thus produced is then transformed into sulphate or hydrochloride. There are also commercial forms of plant glucosamine prepared from the hydrolysis of chitin from Aspergillus niger, a filamentous fungus.