Systematic review of the mechanisms and evidence behind the hypocholesterolaemic effects of HPMC, pectin and chitosan in animal trials.

Dietary fibres have diverse mechanisms in reducing plasma cholesterol, which could be useful for treating high levels of low-density lipoprotein cholesterol (LDL-C). The objective of this review is to determine the state of the evidence for the cholesterol-lowering effects of three selected fibres and their mechanisms, using the most recent animal trials. Therefore, a systematic review was conducted for hydroxypropyl methylcellulose (HPMC), pectin and chitosan in Pubmed, Embase and the Cochrane Library. All fibres reviewed reduced total cholesterol, very low-density lipoprotein cholesterol (VLDL-C) and LDL-C. Pectin gave a small, and chitosan an impressive rise in high-density lipoprotein cholesterol (HDL-C). A limitation of this study is the variety of animal models, each with distinct cholesterol profiles. Possible publication bias was also detected. In conclusion, chitosan seems to be the most promising of the studied fibres. A dietary fibre could be designed that yields the best cholesterol-lowering effect, using experiences in tailoring physicochemical properties and primarily exploiting the biophysical mechanisms of action.