Atherosclerosis (or "hardening of the arteries") usually becomes apparent in adulthood. The physiological processes that cause plaques to form on the walls of the arteries, clogging the arteries and thus interfering with blood flow, begin in childhood. Blood cholesterol levels may be one indicator of this ongoing disease process.
In adults, high levels of total cholesterol and of low-density lipoprotein (LDL or "bad") cholesterol are associated with a higher risk of atherosclerosis. Interestingly, low levels of high-density lipoprotein (HDL or "good") cholesterol are also associated with developing atherosclerosis, while having increased amounts of this HDL cholesterol is protective. Though high blood levels of LDLs promote the deposit of cholesterol and other fatty substances in the walls of the arteries, HDLs act as scavengers in the bloodstream, removing the cholesterol that could damage the arteries.
Studies are not as conclusive about the meaning of cholesterol levels in childhood. There seems to be a weak link between a youngster's elevated cholesterol and his risk of having high cholesterol as an adult.
At present, the American Academy of Pediatrics does not recommend routine cholesterol screening for all children. It does advise screening those children whose parents have a history of high cholesterol levels or early heart attacks (prior to age fifty).
What about treatment for a child with high cholesterol levels (hypercholesterolemia)? Some forms of this disease (familial hypercholesterolemia) are inherited and are caused by abnormal metabolism of fats, leading to abnormally high levels of blood fats, including cholesterol. They usually require intensive therapy during childhood, including dietary changes, exercise, and medication.
Some non-inherited forms of hypercholesterolemia, however, are usually less severe, and the treatment remains controversial. Your doctor may recommend moderate dietary modification, aimed at reducing both fat and cholesterol consumption. As mentioned earlier, the American Academy of Pediatrics suggests an average of 30 percent of calories from fat (with less than one third of those from saturated fats) and a cholesterol intake of no more than 300 milligrams per day. (Dietary cholesterol is found only in foods of animal origin. Some of these foods have very high cholesterol content: One egg has 270 milligrams of cholesterol; a 3.5-ounce serving of liver has 390 milligrams.)
Studies of adults have also shown a link between weight reduction and a decline in both total and LDL cholesterol. Increases in regular physical activity, including aerobic exercise, have been associated with increases in HDL ("good") cholesterol levels too.