Fats and oils are lipids. Their essential role includes being a source of stored energy, a component of cell membranes, serving as the building blocks for hormones, and facilitating the absorption of the fat-soluble vitamins A, D, E, and K. If food calories beyond those needed for energy are consumed most of the extra calories are
stored in the liver and muscles as glycogen, a ready energy source, or as fat—the major storehouse of energy. Some fat, and some essential types of fat that the body
cannot synthesize, is required for good health, but fat need not make up more than 5% of total calories.
Cholesterol is a fatty substance synthesized in the liver and carried throughout the body in the blood bound to proteins called lipoproteins. Cholesterol is a necessary
building block for the production of hormones, cell membranes, and some parts of the body, such as the brain. Cholesterol is also a component of the bile acids that
help the body absorb fats from the intestines. Cholesterol is not found in plant foods, only in animal foods, sources that are usually also high in saturated fats, such
as meat, poultry, shellfish, egg yolks, butter, cheese, and milk. There is no need to obtain cholesterol through food. The human body can synthesize enough cholesterol for good health. Large amounts of dietary cholesterol, but not usually consumed amounts of cholesterol, raise blood cholesterol levels.
The metabolic processes that involve fat and cholesterol are complicated, but the basic physiology is that lipids are transported in the bloodstream by a type of protein
called lipoproteins. Dietary fat is broken down into triglycerides and carried by very-low-density lipoproteins (VLDL) throughout the body where some are converted
to cholesterol-laden particles of low-density lipoprotein cholesterol (called LDL-Cholesterol or LDL-C or LDL). The higher the level of LDL-C, the more likely the formation of the cholesterol-laden blood vessel plaques that cause narrowing of coronary and other arteries and make a heart attack or stroke more likely.
High intake of saturated fat increases unhealthy LDL-C.
Cholesterol is also transported linked to high-density lipoproteins (called HDL-Cholesterol or HDL-C or HDL). HDL-C is sometimes called “good” cholesterol because
a high HDL-C helps prevent the formation of plaques and removes cholesterol from blood vessel plaques. HDL-C seems to work to limit the damage caused by
high LDL-C, but if LDL-C is low, a low level of HDL-C does not seem to increase the risk of arterial damage or a heart attack. Clinical trials of drugs that increased
HDL-C have not shown benefit, nor do individuals genetically predisposed to produce high levels of HDL-C have a lower risk of heart attacks. However, actions that
increase HDL-C naturally, through exercise, weight loss, moderate or no alcohol and, avoidance of trans-fats, refined carbohydrates, and smoking, are associated
with heart health.
In summary, high levels of triglycerides and LDL-C and low levels of HDL-C are associated with an increased risk of atherosclerosis and cardiovascular disease.
The main concern for cardiovascular health is avoiding high LDL-C and high triglycerides. Attaining a high HDL-C is beneficial but of lesser importance to health
and probably of little or no importance when LDL-C is in a healthy low range.
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in the book or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon). Copyright 2020 by J. Joseph Speidel.