An essential part of cell structure, cholesterol is vital for neuron and brain function. It also forms the basis of sex hormones. A fatty substance insoluble in blood, cholesterol requires different types of lipoprotein molecules for transportation through the body's circulatory system. While a total cholesterol level below 200 milligrams per deciliter (mg/dL) is desirable, the levels of individual cholesterol components can more accurately assess risk. A blood test called a lipoprotein profile measures total cholesterol, high density lipoproteins (HDL) and triglycerides. Low density lipoproteins (LDL) are then calculated from a formula using the other values.
LDL
Low density lipoproteins are molecules designed to transport cholesterol into the arteries. An LDL of 70 mg/dL is low-risk. A level of 130 mg/dL or above is considered high risk, because an overabundance of LDL will leave deposits of cholesterol in the arteries where it can form dangerous plaque. LDL is sometimes referred to as "bad cholesterol." Of the lipoproteins, it contains the highest amount of cholesterol.
HDL
High density lipoproteins are molecules that move cholesterol out of the arteries and back to the liver where it can be broken down, re-used or eliminated. HDL levels should be 60 mg/dL or more. Less than 40 mg/dL is considered high risk because a lack of HDL removing cholesterol from the arteries means that deposits remain there to form plaque. HDL is sometimes referred to as "good cholesterol." Of the lipoproteins, it contains the highest amount of protein. Even if total cholesterol measures well under 200, a low HDL level indicates cardiovascular risk. Healthy fats, found in fish oils, avocados, walnuts, flax seeds, hemp seeds, and spirulina are thought to raise blood levels of HDL.
Triglycerides
While most of the body's cholesterol is produced by the liver, dietary fats in the blood take the form of chemicals called triglycerides. These are transported by very low density lipoproteins, or VLDL, which also contain cholesterol. VLDL and liproprotein particles called chylomicrons use enzymes to deposit triglycerides in fat cells, where they are stored until the body converts them to energy. A normal triglyceride level is less than 150 mg/dL. When calorie intake exceeds the number of calories burned, the result is obesity and elevated triglycerides. Weight loss programs that include regular exercise and a diet low in saturated fats and partially hydrogenated oils can help to lower triglycerides as well as LDL cholesterol.
