What is Chitosan?
Chitosan is a naturally derived long chain, linear polysaccharide made up of glucosamine and N-acetyl glucosamine molecules. It has a number of uses in fields as diverse as agriculture, water purification, and medical research and treatment. Chitosan has shown promise as a fat binding weight loss aid, a property which is under investigation.
Where does Chitosan come from?
Chitosan is produced by removing the acetyl group from chitin, which is the material that makes up the exoskeleton of crustaceans, and the cell walls of some fungi.
Chitosan has a diverse range of applications, but as a supplement, it is best known as a source of soluble fibre, and for its ability to encourage weight loss by binding dietary fat and preventing its digestion and absorption by the body. It has also been shown to have a small effect on lowering cholesterol levels and blood pressure. Broadly, these attributes have been supported by a number of scientific studies (1).
Chitosan Benefis for Bodybuilding
With its ability to sequester fat, Chitosan prevents it from being digested and providing energy. This makes it a great supplement for anyone who is cutting and looking to reduce their energy intake.
Chitosan Side Effects, Safety Concerns and Negatives
While chitosan has been relatively well studied, and a comprehensive review of findings showed a small benefit, individual studies are variable and inconsistant, with the larger, better designed studies showing lesser or negligible effects of chitosan supplementation (1).
Chitosan, in theory, works by binding extra fat, which then passes undigested through the digestive tract. This can cause a number of issues. In rats taking large doses of the supplement, this led to a deficiency of minerals and fat soluble vitamins (2), although a short human study lasting a month showed no differences in fat soluble vitamin levels (3). Excess undigested fat can also cause digestive problems such as stomach cramping, diarrhoea, and gas. In spite of the proposed mode of action, a paper which reviewed all significant chitosan studies did not record a significant increase in faecal fat with chitosan use (1).
There has been an isolated case study of arsenic toxicity in a person consuming high dose chitosan supplements, derived fro shellfish. It is worth ensuring the chitosan extract you take has been tested for safe levels of heavy metals (4).
Chitosan Recommended Dosage and Ingredient Timing
A standard dose of chitosan is between 3-6g per day, taken before meals. Most studies have used single doses of 1-1.5g prior to food consumption.
Chitosan is usually sold as a stand alone supplement, but it may be present as an ingredient in some fat burners.
Chitosan will stack with a number of supplements, and would go well with other weight reduction supplements. It has been said that vitamin C may enhance the modest cholesterol lowering properties of chitosan (1). Because chitosan binds to, and prevents the digestion of fats, it is important not to take it at the same time as fat soluble vitamins, some minerals, or fat based supplements like omega-3 fatty acids and MCT oil.
(1) Jull AB, Ni Mhurchu C, Bennett DA, Dunshea-Mooij CA, Rodgers A. Chitosan for overweight or obesity. Cochrane Database Syst Rev. 2008 Jul 16;(3):CD003892.
(2) Deuchi K, Kanauchi O, Shizukuishi M, Kobayashi E. Continuous and massive intake of chitosan affects mineral and fat-soluble vitamin status in rats fed on a high-fat diet. Biosci Biotechnol Biochem. 1995 Jul;59(7):1211-6.
(3) Pittler MH, Abbot NC, Harkness EF, Ernst E. Randomized, double-blind trial of chitosan for body weight reduction. Eur J Clin Nutr. 1999 May;53(5):379-81.
(4) Caraccio, TR. Chronic arsenic (As) toxicity from Chitosan supplement [Abstract]. Clin Tox. 2002;644.