As a soft waxy type of substance, cholesterol is in our blood stream among the lipids (fats), and in all of the cells of our body. A healthy lifestyle requires that we maintain safe levels to perform various functions in our body, such as producing certain hormones and forming cell membranes; excessive levels increase our risk of coronary heart disease and stroke.
Cholesterol is measured in milligrams (mg) per deciliter (dL) of blood. Since it cannot be dissolved in the bloodstream, it must be transported to and from the cells in our body by carriers known as lipoproteins. The two most commonly known types of lipoproteins are High-Density Lipoprotein (HDL) and Low-Density Lipoprotein (LDL). Readings of HDL and LDL are added together to determine the total level in our bloodstream. In general, totals under 200 are considered best.
High-Density Lipoprotein (HDL) is considered the “good” kind, since it tends to transport away from the arteries and back to the liver to be excreted from the body. There is some medical thinking that HDL also slows the growth of plaques, i.e., the thick, hard deposits that build up to clog the arteries. Desirable HDL readings are at least 40 mg/dL for men and at least 50 mg/dL for women.
Low-Density Lipoprotein (LDL) is considered the “bad” kind, since too
much of it can build plaques in the arteries leading to the heart and
the brain, and together with other substances can create atherosclerosis
(clogging of the arteries). Clots may develop next to the plaques,
blocking blood vessels to the heart (causing a heart attack) or to the
brain (causing a stroke). Desirable LDL readings are less than 160 mg/dL
(if you already have heart disease, your doctor may target an LDL level
in the 70-100 mg/dL range).
The American Heart Association recommends a maximum intake of 300 mg/day (200 mg/day is recommended for those with heart disease). On average, American men consume 337 mg/day; American women consume 217 mg/day.
The amount of cholesterol (milligrams) contained in the food we buy is identified on the nutrition label, as well as the recommended daily maximum. Most anyone can reduce their intake by cutting back on saturated fats and trans fats, as contained in all foods from animal sources. Hence we should eat no more than 6 ounces of lean meat, fish or poultry per day, along with low-fat or fat-free dairy products.