Regulation of cholesterol biosynthesis by diet in humans.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing measurement methods and dietary physiology studies without systematic methodology
PubMed 9250128 · doi:10.1093/ajcn/66.2.438
What was done
The authors reviewed available methodologies for measuring human cholesterol synthesis (focusing on mass isotopomer distribution analysis and deuterium incorporation) and synthesized evidence on how dietary factors—including energy restriction, meal frequency, dietary fat type, dietary cholesterol, and phytosterols—regulate endogenous cholesterol biosynthesis.
What was found
The abstract reports directional findings without numerical values or confidence intervals. Food deprivation for as short as 24 hours results in near-complete cessation of cholesterol biosynthesis. Increased meal frequency is associated with substantial suppression of synthesis. Ingestion of oils rich in polyunsaturated fatty acids increases the rate of cholesterol synthesis compared with other fats, despite reducing circulating concentrations. Stepwise addition of dietary cholesterol results in only a modest decline in synthesis while slightly raising plasma concentrations.
Why it matters
This review clarifies that circulating cholesterol concentrations do not always mirror internal synthesis rates, illustrating the metabolic mechanisms through which energy restriction and dietary fat composition alter lipid pools.
Limits
The abstract describes a narrative review rather than a systematic review or meta-analysis. No quantitative effect sizes, variance, sample sizes, or subject population characteristics are reported in the abstract. Clinical outcomes (such as cardiovascular events) were not evaluated.
Cited by
- contradicts Saturated fat intake increases endogenous cholesterol production.