Macronutrients in our diet:
Dietary Fats and Coronary Heart Disease
The cells in your body use fat as an energy source and need cholesterol as a component of their membranes.
Because fat is not soluble in the watery environment of the bloodstream, the liver wraps the fats and cholesterol in a layer of proteins to transport them through the blood.
There are three main types of these proteinwrapped packages, which are called lipoproteins:
• Very–low-density lipoproteins (VLDL)
• Low-density lipoproteins (LDL)
• High-density lipoproteins (HDL).
VLDL carries fats called triglycerides from the liver to other cells in the body. VLDL is converted to LDL, which are smaller cholesterol- rich particles.
The cholesterol in LDL is often referred to as “bad” cholesterol because it can lead to the formation of “plaques” that narrow the arteries and inhibit blood flow throughout the body. (Like the plaque on your teeth, a sort of residual coating which can cause damage and inflammation)
The formation of a blood clot on a piece of plaque can halt blood flow altogether, leading to a heart attack or stroke, which is why a good diet and exercise are encouraged, to stop arteries from getting clogged.
The cholesterol in HDL is called “good” cholesterol. As it travels through the bloodstream, HDL helps reduce the build-up of plaques by removing cholesterol from the walls of the arteries and returning it to the liver for disposal. HDL is like a helpful set of scrubbing bubbles to keep your arteries clean, but of course, you are what you eat.
High levels of triglycerides and LDL cholesterol and low levels of HDL cholesterol are associated with an increased risk of coronary heart disease.
However, reducing blood levels of triglycerides and LDL cholesterol and raising blood levels of HDL cholesterol help prevent the formation of plaques. The different types of fats in food have varying effects on the levels of triglycerides and LDL and HDL cholesterol in your blood.
Triglycerides are the body’s main source of stored energy. Like cholesterol, triglycerides are obtained from food and manufactured in the liver. Also like cholesterol, triglycerides require lipoproteins for their transport in the blood.
Most of the triglycerides in blood are carried by very low density lipoprotein (VLDL). Dietary triglycerides are carried from the intestine on other lipoproteins called chylomicrons.
Elevations in blood triglycerides may promote atherosclerosis (clogging of the arteries) by altering the size, density, and composition of LDL. In addition, very high blood triglyceride levels can lead to inflammation of the pancreas (pancreatitis).
