“Cholesterol is absolutely vital for our existence.
Peter Attia, MD
All steroid hormones (such as Vitamin D) are made from cholesterol, but, as we shall learn, cholesterol is much more than a hormone.
Cholesterol is made in a complex 27-step process from the 2-carbon substance called acetyl-CoA. The 4-ring structure is the chemical signature of a steroid. On the bottom left, there’s a hydrocarbon tail (HO), where cholesterol esterifies (or attaches) to other molecules and a hydroxyl group- top right.
Classified as a fat-soluble lipid, cholesterol is not a fat, it has no calories, and it’s not a source of energy. Cholesterol is a sterol – a high molecular weight alcohol. Animals, plants, and microorganisms require different sterols.
Cholesterol is the animal sterol – found in every cell in animal bodies. It is true that, as a minor component, cholesterol can be found in plant membranes, but the sterols sitosterol and stigmasterol predominate in plants.
According to UK lipid biochemist Michael Gurr: “Only cholesterol will allow animal cells to function as required. Without cholesterol, our bodies would not function properly and we would die.”
Cholesterol waterproofs our trillions of membranes, making it possible for our cells to regulate their internal environments – policing and maintaining “cellular security.” Cholesterol also plays a key role in intra and inter-cellular communications and signaling.
Cholesterol ensures that the cell’s lipid bi-layer (two layers of fat in phospholipid form) is neither too rigid nor too flexible. If that’s not enough, cholesterol is the goddess-like precursor to all adrenal, steroid and sex hormones such as estrogen and testosterone. Without cholesterol, we could not stand, move, think, respond to stress – or reproduce!
Cholesterol is also a major component of bile, an emulsifier required for dietary fats to be broken down and utilized. As a constituent of bile – on its singular route out of the body – cholesterol coats our slowly transiting feces. Only the liver can order cholesterol out of the body – and much of it is recycled. Sorry Cheerios!
The liver is the main site of cholesterol synthesis, but every cell can make cholesterol (except nervous tissue). Our bodies contain up to 100 grams of cholesterol – 90 percent in cell membranes and the rest dissolved in adipose and other tissues. The highest concentration (25 percent) is in the nerve cell connections and in the myelin that protects brain and nervous tissue.
As an example, when an injury occurs on the Teflon-like, slick endothelial layer in an artery – say from high blood sugar – the body’s first responders are cholesterol, blood platelets, specialized white blood cells, and other materials that patch up the injury – similar to a scab forming over a break in the skin.
“Cholesterol is absolutely essential for life,” writes Peter Attia, MD, President and co-Founder of the Nutrition Science Initiative:
“The animal body must have cholesterol to function properly and to manufacture vital hormones and chemicals.”
And, for people whose bodies may not properly synthesize cholesterol, cholesterol in food may be a conditionally essential nutrient.
As you may note, the medical profession has utterly failed to properly describe the essential nature of cholesterol. Future editions of Diet Heart News will continue to expound on the importance of cholesterol and saturated fat in the American diet.
Read the complete article here.