General Description
Chitosan is a natural fiber product derived from chitin, a substance
found in the exoskeletons of shellfish such as shrimp, crabs, and
lobsters. Unlike plant cellulose, which is negatively charged, chitosan
has positively charged amino groups that bind to negatively charged
fats and bile acids. Research shows that, under optimal conditions,
chitosan can bind 4 to 5 times its own weight in fat and bile salts.1
For nearly 30 years, chitosan has been used in water purification
plants for its unique ability to bind to toxic substances. It has
also been used in the pharmaceutical, agricultural, and cosmetic
industries for a variety of purposes. In recent years, chitosan
has become popular as a "fat blocker" dietary supplement for cholesterol
management and weight loss. As a rich source of fiber, chitosan
may also be helpful for promoting bowel function.
Health applications
- Cholesterol management
- Weight loss
- Bowel function
Cholesterol/weight management
Because of its fat-binding capabilities, many people take chitosan
to help lower cholesterol levels and to aid in weight loss. In
laboratory animals, chitosan has shown the ability to lower LDL
and total blood cholesterol levels and raise HDL levels.2-7
In rats fed a high-cholesterol diet, chitosan was shown to help
prevent elevation of blood cholesterol levels.8,9 Studies
on human subjects have shown varying results, but still point
to a favorable effect on cholesterol levels. A study conducted
on 51 obese women who took chitosan for eight weeks showed a reduction
in LDL levels but no change in total serum and HDL cholesterol
levels.10 Another study in which eight healthy males
were given 3-6 grams of chitosan per day showed a reduction in
total serum cholesterol and an increase in HDL.11 Its
ability to block fat absorption has made chitosan a popular weight-loss
product, but its effectiveness in this area has not been proven.12
Dosage/toxicity
Chitosan has an excellent safety record, with studies using up
to 6 grams per day showing no significant side-effects. Chitosan
has no known toxicity, but it can interfere with the absorption
of some minerals, essential fatty acids, and fat-soluble vitamins.13
Vitamin, mineral, and fatty acid supplements may be advisible
for long-term chitosan users. |
