Recent news from EFSA has been the rejection of Article 13.5 claims amongst others that there was not enough evidence to link supplementation with glucosamine with the claimed effects of ” consumption of glucosamine and maintenance of normal joint cartilage in individuals without osteoarthritis”, and “contributes to the protection of joint cartilage exposed to excessive motion or loading and helps to improve the range of motion in joints” (EFSA, 2011, 2012).
The reaction is based on a lack of evidence to support the claim, especially in terms of the quality of information and objectivity provided in the human intervention studies (Ostojic et al., 2007; Yoshimura et al., 2009). Similar claims for glucosamine were rejected in relation to reducing rates of cartilage degeneration and the risk of developing osteoarthritis as part of an Article 14 claim (Reg. 1924/2006) (EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), 2009a), and of an Article 13 (1) claim on glucosamine alone or with chondroitin sulphate and general maintenance of joints (EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), 2009b).
The Benefits Of Glucosamine In Treating Various Forms Of Arthritis
The interest in glucosamine begins in the 50’s with in-vitro studies when it was shown to increase production of collagen and mucopolysaccharides in fibroblasts. Along with chondroitin, it is a key component of collagen. From the 50’s onwards, glucosamine was studied as a means of ameliorating osteoarthritis (OA) in humans as both an injectable and oral supplement (McCarty, 1994). A number of books have expounded glucosamine’s benefits too as in ‘The Arthritis Cure’ and ‘Maximising the Arthritis Cure’ (Thie et al., 2001). The tendency has been to promote this supplement towards the elderly and athletes by linking it to a reduction in joint pain, improving joint strength and operation, rebuilding connective tissues by promoting new cartilage production and inhibiting cartilage breakdown. Chondroitin sulphate from animal cartilage and glucosamine have often been used together in supplements for many of the purposes described above. Further interest into the mechanisms of glucosamine in OA have been prompted by more recent studies (Russell, 1998; Vangsness et al., 2009; Nakamura, 2011).
Glucosamine is a C-2 amino substituted glucose highly soluble in both aqueous and hydrophilic solvents (Nakamura, 2011). It is synthesised ‘in vivo’ by conversion of fructose-6-phosphate to glucosamine-6-phosphate using the amino-acid, glutamine as the amine donor. Acetylation follows before conjugation with uridine diphosphate to enable its incorporation into cartilage (McCarty, 1994). Glucosamine is found in meat, fish and poultry but manufactured by the hydrolysis of crustacean shell chitin (crab, lobster and shrimp for example) or bovine trachea cartilage. Its production makes excellent use of a large waste resource. Glucosamine is usually provided as a supplement in its sulphated, -HCl or N-acetyl form, and often coupled with chondroitin.
The Safety Aspects Of Glucosamine Supplementation
The side-effects are generally mild and infrequent when glucosamine supplementation is followed. The main effects are:-
- rash
- headaches
- stomach irritation and some upsets
- constipation
- diarrhoea
Arthritus Research UK suggest caution for those suffering with diabetes. Glucosamine could increase blood sugar levels which implies that treatments need to be adjusted to ensure these levels do not rise to drastically. There is some evidence that anti-diabetic drugs, chemotherapy and drugs to lower blood cholesterol with glucosamine may also interact.
There is a lot of evidence being accumulated to support supplementation of glucosamine and in due course would be worth listing. Osteoarthritis and the treatment of knee joint pain could be one area for further study despite the EFSA rejection. Clearly though, further high quality intervention human studies which are carefully controlled with an appropriate placebo is required as evidence, before full endorsement for cartilage and joint health.
References
EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (2009a). Scientific Opinion on the substantiation of a health claim related to glucosamine hydrochloride and reduced rate of cartilage degeneration and reduced risk of development of osteoarthritis pursuant to Article 14 of Regulation (EC) No 1924/2006. EFSA Journal, 7(10):1358, 9 pp.
EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (2009b). Scientific Opinion on the substantiation of health claims related to glucosamine alone or in combination with chondroitin sulphate and maintenance of joints (ID 1561, 1562, 1563, 1564, 1565) and reduction of inflammation (ID 1869) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal, 7(9):1264, 17 pp.
EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (2011) Scientific Opinion on the substantiation of a health claim related to glucosamine and maintenance of joints pursuant to Article 13(5) of Regulation (EC) No 1924/2006 http://www.efsa.europa.eu/en/efsajournal/doc/2476.pdf. Downloaded 8th December 2011.
EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (2012). Scientific Opinion on the substantiation of a health claim related to glucosamine and maintenance of normal joint cartilage pursuant to Article 13(5) of Regulation (EC) No 1924/2006 http://www.efsa.europa.eu/en/efsajournal/pub/2691.htm. Downloaded 14th October 2012.
McCarty, M.F. (1994) The neglect of glucosamine as a treatment for osteoarthritis – a personal perspective. Medical Hypothesis 42(5) pp. 323-327
Nakamura, H. (2011) Application of glucosamine on human disease—Osteoarthritis. Carbohydr. Polymers 84(2) pp. 835-839
Ostojic, S.M., Arsic, M., Prodanovic, S., Vukovic, J. Zlatanovic, M. (2007) Glucosamine administration in athletes: effects on recovery of acute knee injury. Res. Sports Med., 15, pp. 113-124.
Russell, A.L. (1998) Glucosamine in osteoarthritis and gastrointestinal disorders: an exemplar of the need for a paradigm shift. Medical Hypothesis 51(4) pp. 347-349
Thie, N.M., Prasad, N.G., Major, P.W. (2001) Evaluation of glucosamine sulfate compared to ibuprofen for the treatment of temporomandibular joint osteoarthritis: a randomized double blind controlled 3 month clinical trial. J. Rheumatology 28(6) pp. 1347-1355
Vangsness, C.T., Spiker, W., Erickson, J. (2009) A Review of Evidence-Based Medicine for Glucosamine and Chondroitin Sulfate Use in Knee Osteoarthritis. Arthroscopy: The Journal of Arthroscopic & Related Surgery 25(1) pp. 86-94
Yoshimura, M., Sakamoto, K., Tsuruta, A., Yamamoto, T., Ishida, K., Yamaguchi, H. Nagaoka, I. (2009) Evaluation of the effect of glucosamine administration on biomarkers for cartilage and bone metabolism in soccer players. Int. J. Mol. Med., 24, pp. 487-494.
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