Your Diet—Can It Kill You?
“You have a severely blocked coronary artery, about a 95% obstruction . . . At this moment you are a heart attack statistic just waiting to happen.”
THIRTY-TWO-YEAR-OLD Joe could hardly believe these words of a cardiologist who examined him to determine the cause of his chest pain. Almost half of those who will die of heart disease are not even aware that they have it.
But what led up to Joe’s condition? ‘For 32 years I ate the typical American “meat and milk” diet,’ laments Joe. ‘Somehow the fact that the American diet is hazardous to my health fell through the cracks.’
Your Diet and Heart Disease
What was wrong with Joe’s diet? Basically, it contained too much cholesterol and fat, especially saturated fat. From his youth, Joe had been setting himself up for coronary heart disease with nearly every forkful of food. A high-fat diet is, in fact, linked to five of the ten leading causes of death in the United States. At the top of the list is coronary disease.
The connection between diet and heart disease is seen in a study conducted in seven countries on some 12,000 men aged 40 to 49. The extremes are particularly revealing. The study showed that Finnish men—eating 20 percent of their calories as saturated fat—had elevated blood-cholesterol levels, while Japanese men—eating only 5 percent of their calories as saturated fat—had low blood-cholesterol levels. And the Finnish men had a rate of heart attack six times greater than the Japanese men!
Coronary heart disease, however, is no longer rare in Japan. In the past several years, as Western-style fast foods have become popular there, the consumption of animal fats has gone up 800 percent. Now, Japanese boys have even higher blood-cholesterol levels than American boys of the same age! Clearly, dietary fat and cholesterol are implicated in life-threatening conditions, particularly heart disease.
The Role of Cholesterol
Cholesterol is a white, waxy substance that is essential to life. It is found in the cells of all humans and animals. Our liver produces cholesterol, and it is also found in varying amounts in foods we eat. Blood carries cholesterol to the cells in molecules called lipoproteins, which are composed of cholesterol, fats, and proteins. The two types of lipoproteins that carry most of the blood cholesterol are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
LDLs are rich in cholesterol. As they circulate in the bloodstream, they enter cells through LDL receptors on cell walls and are broken down for use by the cell. Most cells in the body have such receptors, and they take up some LDL. But the liver is designed so that 70 percent of the removal of LDL from the bloodstream by LDL receptors occurs there.
HDLs, on the other hand, are cholesterol-thirsty molecules. When traveling through the bloodstream, they soak up surplus cholesterol and transport it to the liver. The liver breaks down cholesterol and eliminates it from the body. The body is thus marvelously designed to utilize the cholesterol it needs and to discard the rest.
The problem occurs when there is excessive LDL in the blood. This increases the possibility of a buildup of plaque on artery walls. When plaque buildup occurs, the arteries become narrow and the amount of oxygen-carrying blood that can pass through them decreases. This condition is called atherosclerosis. The process continues slowly and silently, taking decades to manifest discernable symptoms. One symptom is angina pectoris, or chest pain, like Joe experienced.
When a coronary artery is completely blocked, often by a blood clot, the part of the heart that receives blood from that artery dies. The result is a sudden, often deadly, myocardial infarction—better known as a heart attack. Even partial blockage of a coronary artery can lead to death of heart tissue, which may not be manifest by pronounced physical discomfort. Blockage of arteries in other parts of the body can cause strokes, gangrene of the legs, and even loss of kidney function.
Not surprisingly, LDL is called bad cholesterol, and HDL good cholesterol. If LDL tests high or HDL low, the risk of heart disease is high. A simple blood test will often indicate impending danger long before a person experiences noticeable symptoms, such as angina. It is important, then, to keep your blood-cholesterol level in check. Let us now see how your diet can affect this level.