Cholesterol

Cholesterol plays both vital and detrimental roles in our health. There is no nutritional substance as controversial as cholesterol, and no substance about which there is more confusion. There is no other substance as widely publicized by the medical profession -and no bigger health scandal. Cholesterol can strike terror into the minds of misinformed people. The cholesterol scare is big business for doctors, laboratories, and drug companies. It is also a powerful marketing gimmick for vegetable oil and margarine manufacturers who can advertise their products to be 'cholesterol-free'.

The fact is that 999 out of every 1000 people can control their cholesterol level and, more importantly, their cardiovascular health, by nutritional means alone. The remaining 1 in 1000 people can also benefit from nutritional improvement. Medical professionals that are untrained in nutrition cannot help us reach this objective.

A hard, waxy lipid substance that melts at 149°C (300°F), cholesterol is essential for our health, but we do not need to obtain it from foods. Our body can manufacture it from simpler substances (2-carbon acetates) which it derives from the breakdown of sugars, fats, and even proteins, especially when our total intake of these foods supplies us with calories in excess of our body's requirement.

The more excess calories we consume -especially from sugars, and saturated and other non-essential fatty acids -the more pressure there is on our body to make cholesterol. In addition, the more stress we are under, the more cholesterol our body makes, because cholesterol is the precursor of stress hormones.

Vital functions of cholesterol

One function of cholesterol is to compensate for changes in membrane fluidity, keeping it within the narrow limits required for optimal membrane function. This function is so important that nature has equipped each cell with the means to synthesize its own membrane cholesterol.

Our intake of dietary fatty acids -building material for membranes -varies from day to day. More highly unsaturated fatty acids make membranes more fluid, and more saturated fatty acids harden membranes. Cholesterol made by our cells is the regulating factor -it is added to stiffen a membrane that is too loose, and it is removed to fluidize a membrane that is too stiff.

Our body makes steroid hormones from cholesterol. The male and female sex (steroid) hormones develop and maintain the delightful differences between the genders. The three best known of these hormones are the female hormones estrogen and progesterone, and the male hormone testosterone.

Anabolic steroids used by athletes are synthetically made male steroid hormones. They have serious side effects like liver, brain, kidney, ligament, and joint damage. They can also cause cancer. Steroids masculinize the women who use them, resulting in bone growth (square jaws), muscle growth, facial hair, a lower voice, and clitoral enlargement.

Our body also makes adrenal corticosteroid hormones from cholesterol. These hormones include aldosterone, which regulates water balance through our kidneys, increasing sodium retention by our renal tubules; and cortisone, which promotes the synthesis of glucose to prepare our body for fight or flight in response to stress, and also suppresses inflammation.

Our body makes vitamin D, the sunshine vitamin that regulates calcium and phosphorus metabolism, from cholesterol.

Bile acids are derived from cholesterol. Through bile acids, cholesterol performs vital functions in our digestion and absorption of fats, oils, and fat-soluble vitamins from foods. Our body discards excess cholesterol that it no longer needs as bile acids.

Cholesterol is secreted by glands in our skin. It covers and protects our skin against dehydration, cracking, and the wear and tear of sun, wind, and water. In its capacity as skin covering, cholesterol also helps heal skin tissue and prevents infections by foreign organisms.

Cholesterol may also pinch-hit as an antioxidant (AO) when our body's supply of mineral and vitamin AOs is low. High levels of oxidized cholesterol are found in low-density lipoprotein (LOL) and high-density lipoprotein (HDL) transport vehicles when our body lacks food-borne AOs. Some of these AOs, including vitamins C, E, B3, and carotene, as well as the elements selenium, sulphur, and zinc/copper, can lower cholesterol. Chromium, though not an AO itself, can be combined with vitamin B3 to lower cholesterol in 50% of people with high serum levels. The combination of chromium with niacin molecules has been patented as a cholesterol-lowering agent.

Sources of cholesterol

Cholesterol can be made in our body, or it can come from foods.

Homemade cholesterol.
Our cells manufacture the cholesterol they need for their membrane requirements in response to demand. For instance, when we drink alcohol, it dissolves in and fluidizes our membranes. In response, cells build more cholesterol into the membrane, and thereby bring the membrane back to a normal (less fluid) state. As the alcohol wears off, the membrane hardens, and some membrane cholesterol is removed to reestablish normal (greater) membrane fluidity. The extra cholesterol is hooked up (esterified) to an essential fatty acid (EFA) and shipped via our bloodstream to our liver to be changed into bile acids, as long as the vitamins and minerals necessary for this change are present. Our liver dumps bile acids into our intestine to help with fat digestion, and then removes them from our body with solid wastes, as long as our foods contain sufficient fiber and bowel action is regular enough to prevent bile acids in our intestine from being reabsorbed and recycled.
Besides our cells' production of cholesterol, our liver, intestine, adrenal glands, and sex glands all make cholesterol for the other functions in which cholesterol is involved. During pregnancy, the placenta also makes cholesterol, from which it manufactures progesterone, which keeps pregnancy from being terminated.

Making homemade cholesterol.
Our body makes cholesterol by hooking 15 two-carbon acetates (vinegars) end to end to make a 30-carbon chain. Through many steps involving different enzyme catalysts, this chain is cyclized, and finally 3 carbons are clipped off to produce the 27 -carbon cholesterol molecule. The process is complex and interesting for biochemists, but the important nutritional question is to find the source of the 2-carbon acetates.
When our cells break down fatty acids, sugars, starches, or amino acids in our energy-producing mitochondria, they clip off 2-carbon acetates at each step. Alcohol also provides acetates for cholesterol production.

Proteins and EFAs.
Our body conserves proteins as much as possible for building structures and enzymes, so proteins are burned for energy only in extreme circumstances: fasting, some disease states, and after consumption of excessive amounts of protein.
Our body also conserves EFAs for non-fuel functions. Since EFAs are conserved by the body for other vital functions, saturated and monounsaturated fatty acids are the main sources of acetate fragments from fats.
Foods rich in refined carbohydrates also produce an excess of acetates in our body, which 'push' increased cholesterol production. High cholesterol levels in people living in 'processed foods nations' often involve excessive calorie intake.
Stress also increases homemade cholesterol production.

Cholesterol from food sources.
Only foods from animal sources contain cholesterol -plant foods are cholesterol-free. Cholesterol is found in eggs, meat, dairy products, fish, and shellfish. One egg, 1/4 pound of liver, and 1/4 pound of butter each contain about 250 mg of cholesterol; fish and shellfish contain somewhat less.
For 70% of the affluent populations of the world, increased cholesterol consumption decreases cholesterol production within their body by means of a regulating feedback system that protects them. The other 30% of the population may not have adequate feedback, and are wise to limit their cholesterol consumption. What is not clear is to what extent drugs (some of which are known to increase our body's cholesterol production) and other toxic molecules from foods, water, air, and the environment play a role in making the feedback system ineffective.

Body content of cholesterol

The average person's body 'owns' about one-third of a pound (150 grams) of cholesterol. Most of this is found in membranes, and about 7 grams is carried in our blood. The daily turnover of cholesterol is about 1100 mg, or just over 1 gram. These figures vary depending on diet, state of health, and body size. The daily cholesterol turnover on a strict vegetarian diet (who does not eat meat, eggs, or dairy products) is less than 1 gram; bodies of meat eaters turn over more cholesterol as cholesterol consumption increases, but less as fiber consumption decreases.

Removal of cholesterol

Cholesterol is unique in that our body can make it but, once made, cannot break it down. By contrast sugars, fatty acids, amino acids, and nucleic acids can all be taken apart and turned into carbon dioxide, water, and ammonia. As a result of this peculiarity, cholesterol must (and can only) be removed from our body through our stool (in the form of bile acid and cholesterol molecules).

The removal of cholesterol is increased by dietary fiber. If fiber is absent, up to 94% of the cholesterol and bile acids are reabsorbed and recycled. This is one of the reasons why low-fiber diets increase blood cholesterol levels.

Atherosclerosis

About two-thirds of the North American, European, and affluent populations world-wide suffer from atherosclerotic deposits to some degree. These deposits, made of proteins, fats, cholesterol, and minerals, narrow arteries and slow down blood flow. In addition, cholesterol and saturated or denatured fatty acids make our platelets sticky, increasing the risk of a clot forming. The combination of atherosclerosis and clots may completely block an artery, cutting off oxygen and nutrients to the cells of the part of our body supplied by that artery. These cells then die.

If an artery to our brain is blocked, a stroke occurs and, depending on the size and location of the blocked artery, the stroke may be minimal or fatal. Narrowed arteries to our heart produce chest pains (angina pectoris) on exertion or after a meal high in fats that makes blood thicker and less capable of supplying oxygen. Blockage of an artery supplying our heart results in a heart attack (coronary occlusion). If a clot blocks an artery in our lungs, pulmonary embolism occurs. A blocked artery to our legs results in impaired circulation that can lead to gangrene. Blindness and deafness can occur when arteries supplying sense organs are blocked.

Atherosclerotic deposits also 'harden' our arteries, resulting in raised blood pressure because the arteries' resilience, which normally takes up the pressure generated by each heartbeat (contraction), is lost. This results in a heavier load on our heart and kidneys which, when prolonged, leads to water retention (edema) and heart and kidney failure.