What does chitosan do?
Chitosan is a polysaccharide found in the shells of crustaceans.
Like dietary fiber, chitosan is not digestible but may have beneficial effects on the gastrointestinal tract. Chitosan appears to reduce the absorption of bile acids or cholesterol; either of these effects may cause a lowering of blood cholesterol.1 This effect has been repeatedly demonstrated in animals, and a preliminary human study showed that 3-6 grams per day of chitosan taken for 2 weeks resulted in a 6% drop in cholesterol and a 10% increase in HDL ("good") cholesterol.2 Another preliminary trial showed a 43% lowering of total cholesterol in people being treated for kidney failure with dialysis who took 4 grams per day of chitosan for 12 weeks. These people also appeared to have improved kidney function and less severe anemia after chitosan treatment.3
Chitosan in large amounts, given with vitamin C, has been shown to reduce the absorption of dietary fat in animals fed a high-fat diet.4 5 6 However, the absorption of minerals and fat-soluble vitamins was also reduced by feeding animals large amounts of chitosan.7 No studies have been done on the effects of chitosan on dietary fat absorption in humans.
Chitosan may also have an effect on the type of bacteria living in the intestines or on the action of these bacteria. A small human study found that taking 3-6 grams per day of chitosan for two weeks reduced indicators of putrefaction in the intestines,8 a change that might help prevent diseases such as colon cancer.9
Where is chitosan found?
Chitosan is extracted from the shells of crustaceans, such as shrimp and crab.
Chitosan has been used in connection with the following conditions (refer to the individual health concern for complete information):