Creating a free account will enable you to subscribe to our daily and weekly email newsletters, as well as customize your reading experience to show only the categories most relevant to you.
Signing up only take a few minutes, so why not give it a try and see what you've been missing out on.
Glucosamine is a naturally occurring substance found in the fluid around our joints. It is naturally present in animal bones, bone marrow, shellfish and fungi.
Glucosamine plays a vital role in building cartilage and is commonly consumed as a supplement by people with arthritis, especially osteoarthritis.
Glucosamine, especially glucosamine sulfate, is harvested from the shells of shellfish and put into dietary supplements. It can also be made in the laboratory.
Glucosamine can come in different forms, including:
Although similar, the three forms may not have the same effect when used as dietary supplements.
Most studies that have examined the potential health benefits of glucosamine have focused on glucosamine sulfate.
Glucosamine-containing dietary supplements often have other ingredients added in, including chondroitin sulfate, MSM or shark cartilage. Although some people say the combinations help, there is no scientific proof that they do, says the National Institutes of Health.1
The National Institutes of Health (NIH) adds that skin creams containing glucosamine for arthritis pain probably provide relief because of other substances in them, and not the glucosamine. "There is no evidence that glucosamine can be absorbed through the skin."
The NIH also commented that some glucosamine sulfate products do not contain what their labeling states - tests showed from 0% to 100% glucosamine content. In other tests, when the label claimed the product had glucosamine hydrochloride, it was glucosamine sulfate.
Glucosamine is vital for building cartilage. Cartilage is a flexible, tough connective tissue found in several areas of the body. This fine, rubbery tissue functions as padding, a cushion for bones and joints.
Joint cartilage requires glucosamine because it is a precursor for glycosaminoglycans (glucosamine makes glycosaminoglycans). Glycosaminoglycans are a major component of joint cartilage.
Sulfur needs to be incorporated into cartilage in order to make and repair it. Glucosamine plays a crucial role in incorporating sulfur into cartilage.
As we age, glucosamine levels go down, which can lead to eventual joint deterioration.
According to the National Center for Complementary and Alternative Therapy2, a 2007 National Health Interview survey found that 17.7% of adults in the USA regularly took some type of dietary supplement. Of those people, 19.9% took glucosamine, the second most popular dietary supplement after fish oil/omega 3/DHA (37.4%).
Glucosamine supplements are most commonly taken by people suffering from osteoarthritis, inflammatory bowel disease (IBD) and ulcerative colitis.
Several scientific studies have shown that glucosamine supplements may help patients with osteoarthritis (OA), especially OA of the hip or knee.
The studies found that glucosamine probably:
However, the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), which was performed at 16 sites across the United State and published in NEJM (New England Journal of Medicine3 found that glucosamine plus chondroitin sulfate did not provide significant relief from osteoarthritis among all 1,600 participants.
In a smaller subgroup of the study, however, patients with moderate-to-severe pain reported significant relief from the glucosamine/chondroitin combination.
In 2008, researchers reported on a 2-year ancillary study at nine sites in the USA with a subset of participants from the original trial. The results, published in Arthritis & Rheumatism showed that glucosamine and chondroitin sulfate, together or alone, fared no better than placebo4 in slowing loss of cartilage in knee osteoarthritis. However, the patients on placebo had a smaller loss of cartilage or joint space width than predicted.
Most studies appear to indicate that if you have osteoarthritis and your symptoms of pain are moderate-to-severe, glucosamine or a glucosamine/chondroitin combination may help, otherwise it is probably no better than placebo.
IBD involves long-term inflammation of part or all of the digestive tract. Examples of IBD include Crohn's disease and ulcerative colitis. IBD is painful and can be debilitating and sometimes life-threating if there are complications.
Ulcerative colitis affects part of the digestive tract while Crohn's disease can cause inflammation in any part of the lining along the digestive tract, and frequently spreads deep into affected tissue.
Researchers in a pilot study carried out at the University Department of Paediatric Gastroenterology, Royal Free, London, UK, concluded that N-acetyl glucosamine (GlcNAc), a glucosamine-like dietary supplement, showed promise as a cheap and non-toxic treatment in chronic inflammatory bowel disease for children who did not respond well to other treatments (severe treatment-resistant inflammatory bowel disease). Ten had Crohn's disease and two ulcerative colitis.
As it was a small study the investigators wrote in the journal Alimentary Pharmacology & Therapeutics5 (December 2000 issue) "It may have the potential to be helpful in stricturing disease. However, controlled trials and an assessment of enteric-release preparations are required to confirm its efficacy and establish indications for use."
Researchers from Juntendo University, School of Medicine, Tokyo, carried out experiments on IBD induced laboratory rats. They reported in the International Journal of Molecular Medicine6 that "....glucosamine could prove to be a useful agent for IBD."
Scientists at the University of California, Irvine, found that N-acetyl glucosamine (GlcNAc) supplements suppressed the damaging autoimmune response that occurs in MS (multiple sclerosis).
Dr. Michael Demetriou, Ani Grigorian and colleagues explained in The Journal of Biological Chemistry7 that GlcNAc inhibited the growth and function of abnormal T-cells that mistakenly make the MS patient's immune system attack and destroy central nervous system tissue that insulates nerves (myelin).
Dr. Demetriou said "This sugar-based supplement corrects a genetic defect that induces cells to attack the body in MS, making metabolic therapy a rational approach that differs significantly from currently available treatments."
In their experiment they used laboratory mice with MS-like autoimmune disease. The scientists found that when the mice with leg weaknesses were give GlcNAc orally, the supplement suppressed T-cell hyperactivity and autoimmune response by raising sugar modifications to the T-cell proteins, resulting in a reversal of the progression to paralysis.
A research team from the Jefferson Medical College found that OTC (over-the-counter) glucosamine helped delay the onset of MS symptoms in an animal experiment. They found it also improved the mice's ability to move and walk.8
Glucosamine is used for many other conditions and illnesses. However, most studies have found they are either ineffective, no conclusion can be reached, while some warn of potential harms (as in "allergies" below). From the list below, the only one with a positive study is glucosamine use for temporomandibular joint problems:
According to the National Institutes of Health, glucosamine is LIKELY SAFE when used properly by adults.
The NIH adds that some mild side effects have occasionally (rarely) been associated with glucosamine intake, including:
Pregnancy and breastfeeding - nobody knows whether glucosamine is safe for pregnant or breastfeeding mothers. Until scientific studies can conclude one way or another, the NIH recommends women do not take glucosamine while breastfeeding or during pregnancy.
Asthma - several medical journals warn that glucosamine may cause an asthma attack in some people. One report linked asthma to glucosamine intake, according to the NIH, but the researchers could not determine compellingly whether glucosamine was the culprit.
Diabetes - some earlier studies had suggested that glucosamine might raise blood glucose levels in patients with diabetes. Later studies suggested the opposite. It appears that glucosamine probably does not affect blood glucose levels in patients with type 2 diabetes.
Shellfish allergy - some glucosamine products are made from the shells of shellfish. People with shellfish allergies should be aware of this and consider asking their pharmacist for man-made glucosamine supplements. However, the NIH adds that US health authorities have received no reports of allergic reactions to glucosamine among people with shellfish allergies.
Written by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without the permission of Medical News Today.
Visit our Complementary Medicine / Alternative Medicine category page for the latest news on this subject.
Please use one of the following formats to cite this article in your essay, paper or report:
Nordqvist, Christian. "What is glucosamine?." Medical News Today. MediLexicon, Intl., 12 Nov. 2013. Web.
8 Dec. 2013. <http://www.medicalnewstoday.com/articles/265748>
Nordqvist, C. (2013, November 12). "What is glucosamine?." Medical News Today. Retrieved from
Please note: If no author information is provided, the source is cited instead.
If you write about specific medications, operations, or procedures please do not name healthcare professionals by name.
For any corrections of factual information, or to contact the our editorial team, please use our feedback form. Please send any medical news or health news press releases to:
Note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional. For more information, please read our terms and conditions.
This page was printed from: http://www.medicalnewstoday.com/articles/265748.php
Visit www.medicalnewstoday.com for medical news and health news headlines posted throughout the day, every day.
© 2004-2013 All rights reserved. MNT (logo) is the registered trade mark of MediLexicon International Limited.