Dietary fibre and lipid metabolism.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing animal models, in vitro mechanisms, and general human observations.
What was done
Method and design summarized from animal models (rats, chickens, rabbits, monkeys) and human observations examining the effects of dietary fiber on serum and tissue lipids, lipoprotein fractions, bile acid binding, lipid excretion, and experimental atherosclerosis.
What was found
The abstract reports no numerical values. Qualitatively, it reports that in cholesterol-fed rats, some fibers lowered serum and liver cholesterol, whereas cellulose increased liver and carcass cholesterol. In chickens, rabbits, and monkeys, cellulose exerted the least beneficial effect on atherosclerosis. In humans, insoluble fibers (bran, cellulose) were not hypocholesterolaemic, whereas soluble fibers (guar gum, pectin) lowered cholesterol and altered LDL and HDL levels. In vitro and mechanistic data showed fibers bind bile acids and lipids and influence cholesterol absorption rate.
Why it matters
It establishes that lipid-lowering effects are specific to soluble fibers rather than dietary fiber as a whole, highlighting the role of fiber solubility and bile acid binding in cholesterol regulation.
Limits
As a narrative review, no search strategy, sample sizes, or quantitative data are provided in the abstract. Findings heavily rely on animal models and in vitro binding assays rather than controlled human clinical trials.
Cited by
- supports Dietary fiber binds to cholesterol and clears it from the body.