Cholesterol - Endogenous

Introduction

This section outlines the facts associated with Cholesterol (as opposed to dietary Cholesterol).

 View Cholesterol's Metabolic Pathway

    Approximately 70% of the body's Cholesterol content is produced by the body independent of dietary sources:

 The body increases its production of endogenous Cholesterol if dietary Cholesterol is deficient.

 The body decreases its production of endogenous Cholesterol if dietary Cholesterol is excessive.

 Even if massive amounts of dietary cholesterol are consumed the body normally reduces the amount of Cholesterol absorbed from the diet and increases its excretion of Cholesterol via Bile.

 Approximately 10% of endogenous Cholesterol is synthesized in the Liver.  Approximately 15% of endogenous Cholesterol is synthesized in the Intestines.  Endogenous Cholesterol synthesis occurs in the Cytoplasm and Microsomes.

Enzymes

 Cholesterol Esterase catalyzes the conversion of Cholesterol to Pregnenolone.

Hormones

 Adrenocorticotropic Hormone (ACTH) facilitates the conversion of Cholesterol to Pregnenolone (by increasing the activity of the Cholesterol Esterase enzyme that catalyzes the conversion of Cholesterol to Pregnenolone within the Adrenal Glands).

Alcohols

    Alcohol (ethanol) triggers the production of Cholesterol within the Cell Membranes:

 Alcohol fluidizes the Cell Membranes.  Cholesterol is produced in order to bring the Cell Membrane back to a less fluid state,  The extra Cholesterol is later ejected from the Cell Membrane via the bloodstream to the Liver for conversion to Bile Acids

 Alcohol contributes two carbon Acetic Acid chains towards the manufacture of Cholesterol.

Alkaloids

 The Nicotine ingested from Tobacco smoking may increase Cholesterol production.

Carbohydrates

 Excessive consumption of dietary Carbohydrates may cause some of the excess to be converted within the body to Cholesterol (via ATP-Citrate Lyase enzyme):

-           Fructose serves in part as a raw material for the synthesis of endogenous Cholesterol and excessive consumption of dietary Fructose may increase serum Cholesterol levels by an average of 9%.  ^[1]

 Sucrose may increase the production of endogenous Cholesterol.  ^[2]

Enzymes

 ATP-Citrate Lyase stimulates the conversion of excess dietary Carbohydrates to Cholesterol (or Adipose Tissue).

 HMG-CoA Reductase is an essential catalyst for the endogenous production of Cholesterol.

Hormones

 High Insulin levels may cause an increase in the endogenous production of Cholesterol.