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The promise of a pill


Kate Beneditct


Fat Busters, Fat Trappers, Fat Magnets and Fat Absorbers all have one ‘miraculous’ agent in common – chitosan.  Why is this supplement all the rage in today’s weight loss market?  Will chitosan live up to its touted potential?



The dietary supplement, chitosan is the processed, more water-soluble form of one of the most common substances in nature: chitin (KITE-in).  The exoskeletons of arthropods (ants, shellfish, etc.) and the walls of many molds, yeast and fungi contain this building block of nature.


Chitosan was first discovered in 1811 by Henri Braconnot, director of the botanical garden in Nancy, France.  Bracannot observed that a certain substance (chitin) found in mushrooms did not dissolve in sulfuric acid. Over the last 200 years, the exploration of chitosan has taken on many different forms.  Several other researchers continue to build on the original finding of Bracannot, discovering new uses for chitin as they find different forms of it in nature.


Chitosan aids in the “reduction of triglycerides due to its ability to bind dietary lipids, thereby reducing intestinal lipid absorption” (Koide, 1998).  Translation? Basically, chitin molecules have the ability to latch on to heavy metals, amino acids and FAT.  Chitin may be able to ‘soak up’ fat in the intestine and flush it through the body before it can be absorbed.  If effective, this process should lead to weight reduction.





    According to Sally Squires, in the March 28, 2000 issue of The Washington Post,  several factors involving chitosan should be considered before buying chitosan-based products:

1) The composition of chitin can vary depending on the seawater, the animal from which it is taken, and the time of year.  There is no ‘pure form’ that can be counted on.

2) Following the Dietary Supplement Health and Nutrition Act in 1994, the FDA has a limited ability to regulate vitamins, minerals and other dietary supplements (i.e. chitosan).  It is, therefore, possible to stock shevles full of a product without providing related scientific evidence.

3) The Federal Trade Commission (FTC) won an $8.3 million judgment against  a company violating federal consumer protection laws with false claims concerning chitin.

4) The FTC lawsuit is the first of several additional (non FTC) suits for false claims regarding chitin and chitosan, including a lawsuit filed by both Napa and Sonoma counties in California.


Apparently, this ‘wonder pill’ (along with other dietary supplements and appetite suppressants) has attracted many people in the market for  weight loss programs.  Sales of such products have reached an estimated $1.7 billion.  Does this number mean that we have discovered a way around the seemingly unbending rules of the ‘eat less, exercise more’ diet plan?  Can we finally indulge and treat ourselves to high calorie, high fat foods without consequence?  To find out, we must dig deeper.


To begin, the most commonly cited study by the marketers and manufacturers of chitosan-based products is the 1994 ARS Medicina (Helsinki) Report.  In this study, test subjects lost eight percent of body fat and reduced cholesterol by thirty-two percent in four weeks. 

Secondly, in other various studies, chitin-chitosan  “lowers plasma cholesterol and triglycerides and improves the HDL-cholesterol/total cholesterol level" (Koide, 1998, Razdan et. al., 1994, Okamoto et. al., 1995, Usami et. al., 1994).

Looking at these pieces of evidence, one might be sufficiently convinced that chitosan’s claims are indeed true.  When taking the designs of the studies into consideration, however, the evidence appears in a much different light.

The 1994 ARS Medicina (Helsinki) Report, and others like it, appear to be loosely designed.  Uncontrolled, anectdotal evidence seems to be the only available evidence in research up to date.

Cholesterol lowering evidence reported in the other articles is achieved in another noteworthy fashion.  These studies were conducted on mice, canines, guinea pigs and broiler chickens.  A lack of published human studies reflects the strong need for further research before promoting chitin based products to the public. 

Unfortunately, only one such ‘well designed’ study has been published.  In 1999, M.H. Pittler,, conducted a randomized, placebo controlled, double blind study with 30 overweight subjects who were randomly assigned to either a ‘treatment group’ which received four capsules of chitosan twice a day for twenty-eight days, or to a ‘placebo group’ which received a placebo under the same regimen.  These participants were instructed not to alter their diets and were asked to keep a detailed food diary to track food consumption.  Measurements were taken at baseline, after fourteen days of treatment, and after twenty-eight days of treatment.  The results revealed no significant difference between the two groups on any of the following: body mass index; serum cholesterol; triglycerides; Vitamin A, D, E, or beta-carotene levels.

Taken together, these studies suggest  that our hopes of a miracle dietary supplement are still just hopes.  'Hard and fast' evidence of the effectiveness of chitosan appears to be absent from the literature.  The search for a miracle pill continues.


Koide, S.S. (1998). Chitin-Chitosan: Properties, Benefits and Risks.  Nutrition Research, 8:6, 1091-1101.

Nishimura, K., Nishimura, S., Nishi, N., Tokura S., Azuma. I. (1985).  Vaccine, 3, 379-384.

Pittler, M.H.; Abbot, N.C.; Harkness, E.F.; Ernst E. (1999). Randomized, Double-Blind Trial of Chitosan for Body Weight Reduction. European Journal of Clinical Nutrition (UK) 53, 379-381.

Razdan, A., Petterson O. (1994). Effect of chitin and chitosan on nutrient digestibility and plasma lipid concentrations in broiler chicken. British Journal of Nutrition, 72, 277-288.

Usami, Y., Okamoto, Y., Minami S., Matsuhashi, A., Kumazawa, N.H., Tonioka, S., Shigemasa, Y.  (1994).  Migration of canine neutrophiles of chitin and chitosan. Journal of Veterinary Medical Science, 56, 1215-1216.





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