Triglycerides, fat and cholesterol
THERE IS A BIG DIFFERENCE BETWEEN TRIGLYCERIDES AND CHOLESTEROL. CHOLESTEROL IS A WAXY, FAT-LIKE SUBSTANCE WITH A COMPLEX STRUCTURE THAT LOOKS A SMALL PIECE OF HONEYCOMB. CHOLESTEROL IS NOT USED FOR ENERGY; IT IS A STRUCTURAL ELEMENT IN ALL CELLS AND SERV
DEAR DR. BLONZ: A recent blood test showed that my cholesterol levels were fine, but my triglycerides were slightly elevated. You mention them periodically, but please explain what triglycerides are and the role my diet might be playing.
— F.L., Oakland, California
DEAR F.L.: The role of triglycerides often confuses people. That’s not surprising, given the speed with which complex health terms have encroached upon our daily lives.
Think of triglycerides as the body’s most concentrated form of stored energy. (For this discussion, think of the terms “fats” and “triglycerides” as compatible.) The human body is designed to be mobile and to conserve energy. Triglycerides are the form into which excess energy is converted, and also the way they get packaged for transport and storage.
Contrast this with plants, where the mission is to grow rapidly; energy in plants gets made into carbohydrates, which serve as a building material. (If we stored energy as carbohydrates, we would be too bulky to move.) The fascinating shift in plant life is with their seeds, where their light weight allows them to travel on the wind or with animals to land — and grow
BOTH TRIGLYCERIDES AND CHOLESTEROL ARE MEMBERS OF THE LIPID FAMILY. BOTH SHARE THE DUBIOUS DISTINCTION OF HAVING THEIR ELEVATED BLOOD LEVELS ASSOCIATED WITH AN INCREASED RISK OF HEART DISEASE.
— in a new area. In seeds, energy is stored as fat.
A list of triglycerides would include the fats in our diet (butter, cooking oils, etc.), those in our bloodstream, and the fat that eventually makes its way to the body’s energy storage depots. All triglycerides are built like a squat version of the letter “E”, where the three prongs are individual saturated or unsaturated fatty acids attached to a glycerol backbone.
There is a big difference between triglycerides and cholesterol. Cholesterol is a waxy, fat-like substance with a complex structure that looks a small piece of honeycomb. Cholesterol is not used for energy; it i s a structural element in all cells and serves as a raw material in making many hormones.
Both triglycerides and cholesterol are members of the lipid family. In addition, both travel through the body in packages known as lipoproteins. And finally, both share the dubious distinction of having their elevated blood levels associated with an increased risk of heart disease. The blood triglyceride level usually goes up after eating, even if there’s a limited amount of fat in the meal. This occurs because the body is programmed to convert excess protein or carbohydrate into triglycerides, the form of energy best suited for transport and storage. Consuming alcohol or excess sugars such as fructose, sucrose
or glucose will also increase triglycerides.
Should you be concerned about your triglyceride level? As blood tests for triglycerides are typically taken after a fast, any effects from last meal should be over. Given this, if you still have an elevated triglyceride level, it would be something to be discussed with your health professional. Much will depend on your health profile and history. You and your doctor will decide whether this is something to be monitored or if additional tests may be needed to rule out any ongoing problems.
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