Cholesterol - "Our Hero"

Present in ALL our cells, cholesterol has the following responsibilites:

Regulates cell membrane integrity

-   Makes membranes less permeable to most biological molecules

-   Cholesterol provides membrane integrity when dietary saturated fat is missing - when excess dietary polyunsaturated fatty acids replace saturated fat in the diet, it causes cell walls to become flabby.When this happens, cholesterol from the blood (or synthesized by the cell) is added into the cell membrane giving watertight protection and structural integrity -this is the reason why serum cholesterol levels go down temporarily when we replace dietary saturated fats with polyunsaturated oils - Cholesterol is removed from the cell membrane when dietary saturated fat provides the required stiffness.

Membrane cholesterol content varies with particular tissue membrane function

-   Membranes with high cholesterol-to-phospholipid ratios function as a protective barrier - have high stability and low permeability.

•   Nerve Function Protection - The highest concentration of cholesterol in the body is found in the critical brain and nervous system. Every second molecule in the myelin sheath surrounding and insulating nerves is cholesterol, where it affects proper nerve conduction and normal brain function, by providing structural balance to their high polyunsaturated content.

-   Organelle membranes inside cells have low cholesterol ratios - making them fluid and permeable; e.g. mitochondria.

-   Intestinal wall Integrity - Cholesterol's role maintaining the intestinal wall integrity prevents leaky gut syndrome and other intestinal problems.

Precursor of Sex hormones

-    DHEA (dehydroepiandrosterone), the “mother” steroid hormone.   Synthesized from cholesterol by the adrenal cortex. DHEA is the precursor for estrogen, Testosterone and Progesterone (to prevent miscarriage in pregnancy, the placenta produces cholesterol, from which it makes Progesterone); cholesterol stored in the ovaries and testes is converted to steroid hormones.

-   DHEA is also called the “anti-aging” hormone.    Good evidence supports that increasing DHEA blood levels decreases risk of cancer, cardiovascular disease, diabetes, obesity, senility, Alzheimer's disease, and premature death. People with a positive outlook actually create a self-sustaining cycle of DHEA production!

Raw material for Vitamin D

-   Cholesterol provides the raw material to make vitamin D.    D regulates calcium and phosphorus metabolism to support bone health. Vitamin D is also required for nerve function, growth, mineral metabolism, muscles, INSULIN production, reproduction, and the immune system.

Raw material for Adrenal Stress hormones

-   The more stress we are under, the more cholesterol our body makes - because the corticosteroid stress hormones are synthesized from cholesterol in the adrenal cortex:

•   CORTISOL - Provides suitable response to stress, also controls carbohydrate, fat and protein metabolism and is a potent anti-inflammatory agent that protects against heart disease;

•   CORTISONE - Promotes glucose synthesis for fight or flight response to stress. Suppresses inflammation.

•   ALDOSTERONE - Controls electrolyte and water levels, mainly by promoting sodium retention in the kidney.

Raw material for Bile salts

-    Required for fat digestion and the metabolism of the fat soluble vitamins A, D, E and K - Cholesterol is oxidized by the liver into bile acids, which along with cholesterol are excreted from the liver into bile and stored in the gallbladder. Fat consumption causes bile to be “squirted” from the gallbladder into the upper small intestine (duodenum) to digest fat. Approximately 95% of bile acids are reabsorbed from the intestines, and the remainder lost in the feces

Brain's SEROTONIN receptors need cholesterol for their proper function

Dozens of studies link cholesterol deficiency to:

-   Aggressive emotions and actions

Annals of Internal Medicine 1998;128(6):478-487;

The Journal of the American Medical Association 1997;278:313-321;

Low cholesterol linked to violence

-    Depression / Suicide - Canadian researchers found that those in the lowest quarter of total cholesterol concentration had > 6 times the risk of committing suicide as those in the highest quarter. Epidemiology 2001 Mar;12:168-72

“Cholesterol to the rescue!”

-   Cholesterol is transferred to tissues in lipoprotein carriers to repair damage caused by chronic inflammation - it is the repair “superglue”used to keep cell membranes from falling apart. E.g. when your arteries are damaged or lacking structural integrity due to insufficient dietary vitamin C.