Atherosclerosis: The Silent Killer

Atherosclerosis: The Silent Killer

Atherosclerosis is one of a group of health problems that define coronary artery disease, oftentimes referred to as heart disease. Atherosclerosis is the leading cause of heart disease in the United States. The following is the definition provided by the American Heart Association:

Atherosclerosis (ath"er-o-skleh-RO'sis) comes from the Greek words athero (meaning gruel or paste) and sclerosis (hardness). It's the name of the process in which deposits of fatty substances, cholesterol, cellular waste products, calcium and other substances build up in the inner lining of an artery. This buildup is called plaque. It usually affects large and medium-sized arteries. Some hardening of arteries often occurs when people grow older (AHA, 2005).

Atherosclerosis is different from Arteriosclerosis, though the two are oftentimes concurrently present as a result of heart disease and are likewise confused. Arteriosclerosis is defined by the Well-Net group as:

...during which the arteries of the cardiovascular system develop areas which become hard and brittle. Vessels become thickened. There is a loss of elasticity. It can involve the arteries of the cardiovascular system, the brain, kidneys, upper and lower extremities. This occurs because of the deposition of calcium in their walls.

Atherosclerosis often leads to coronary heart disease, strokes, and other disorders because of the occurrence of blood clots which form in the narrowed arteries; hardening of the arteries, on the other hand occur only in advanced stages (Lawrence, 1997).

There are factors that can be controlled to aid in the prevention of atherosclerosis. The following research will address seven major "controllable" factors with special focus on how a person's diet can help minimize the risk of developing this debilitating disease, or preventing a heart attack if the disease is already present.

According to The Cleveland Clinic Heart Center, "Coronary artery disease, also called coronary heart disease, or simply, heart disease, is the No. 1 killer in America, affecting more than 12 million Americans (Webmd.com, 2005)."

Atherosclerosis occurs when the arteries that feed blood to the heart become narrowed due to the build up of plaque. This plaque is made up of fat, LDL cholesterol, calcium and other deposits. Plaque sticks to the walls of the coronary arteries where it eventually builds up and hardens, thus narrowing the passageways. Eventually this obstruction leads to the lack of blood and oxygen to the heart, which ultimately results in a heart attack (NHLBI.com, 2005).

There are eight major contributors that result in heart disease: heredity, smoking, high blood pressure, high blood cholesterol (LDL), physical inactivity, obesity, diabetes, and arterial inflammation. The remaining seven contributors can be controlled, or at least reduced to safer levels that will help prevent or even reverse the disease, prevent a heart attack, and prolong one's life.

Smoking

Extensive clinical studies have proven that smoking is a major factor in the development and progression of arterial sclerosis. Additionally, the risk of heart disease is more than twice that of non-smokers. According to the University of California at Berkeley, "Anywhere from 20 to 40% (100,000 to 200,000 every year) of all heart disease deaths in the U.S. are directly attributable to smoking.

The American Heart Association reports an even gloomier number, "Cigarette smoking is the most important preventable cause of premature death in the United States. It accounts for more than 440,000 of the more than 2.4 million annual deaths. Cigarette smokers have a higher risk of developing a number of chronic disorders. (AHA, 2005).

Smoking more than doubles one's chances of eventually having a heart attack and increases the chance of dying from it by 70%. Smoking is also the leading cause of sudden cardiac death. The good news is that by quitting smoking now, it will reduce the risk of developing heart disease. Within five to ten years of quitting, the risk of heart attack declines to a level similar to that of people who never smoked, regardless of how long one smoked (Berkeley Wellness.com, 2005).

How does smoking cause heart disease, or arteriosclerosis? Smoking causes heart disease by creating several dangerous conditions, both short term and long term:

The role of smoking in Coronary Heart Disease: Inhaling tobacco smoke causes several immediate responses within the heart and its blood vessels. Within one minute of starting to smoke, the heart rate begins to rise: it may increase by as much as 30 percent during the first 10 minutes of smoking. Nicotine raises blood pressure: blood vessels constrict which forces the heart to work harder to deliver oxygen to the rest of the body. Meanwhile, carbon monoxide in tobacco smoke exerts a negative effect on the heart by reducing the blood's ability to carry oxygen (ASH, 2004).

Smoking and arterial disease: Smoking tends to increase blood cholesterol levels. Furthermore, the ratio of high-density lipoprotein cholesterol (the "good" cholesterol) to low-density lipoprotein cholesterol (the "bad" cholesterol) tends to be lower in smokers compared to non-smokers. Smoking also raises the levels of fibrinogen (a protein which causes blood to clot) and increases platelet production (also involved in the formation of blood clots) which makes the blood stickier. Carbon monoxide attaches itself to hemoglobin (the oxygen-carrying pigment in red blood cells) much more easily than oxygen does. This reduces the amount of oxygen available to the tissues. All these factors make smokers more at risk of developing various forms of atherosclerotic disease. As the atherosclerotic process progresses, blood flows less easily through rigid and narrowed arteries and the blood is more likely to form a thrombosis (clot). This sudden blockage of an artery may lead to a fatal heart attack, a stroke or gangrene of the leg (ASH, 2004).

By quitting smoking at anytime, the short-term effects reduce almost immediately. The long-term effects begin to reduce such that in a few years the former smoker may not have a risk for heart disease any greater than the population of those who never smoked.

High Blood Pressure

High blood pressure is another factor in heart disease. It has a number of causes, such as smoking mentioned above. However, other factors, including diet can also contribute to or cause high blood pressure. High blood pressure, also known as hypertension, results from arterial narrowing which in turn causes blood to be pumped with greater force against the arterial walls.