Mechanisms of action.
Chitosan is believed to affect cholesterol levels and weight because it has positively charged amino groups at the same pH as the gastrointestinal tract.
These amino groups are believed to bind to negatively charged molecules, such as lipids and bile, preventing their absorption and storage by the body.
The action of chito- san in cholesterol management may be explained by the theory that ingested chitosan salts react with fatty acids and bind lipids because of hydrophobic in- teractions; these bound lipids are ex- tracted rather than absorbed. Animal studies in rats, mice, and chickens indicate that chitosan decreases very-low-density- lipoprotein-cholesterol levels while increasing high-density-lipoprotein (HDL)-cholesterol levels.4 In vitro studies have also shown that O-carboxymethyl chitosan beads absorb low-density- lipoprotein (LDL) cholesterol.4
teractions