Smoking and Atherosclerosis

Smoking is Hard on the Heart

Illustration showing the buildup of plaque inside artery walls. Science Picture Co/Collection Mix: Subjects/Getty Images

Atherosclerosis is a life-threatening disease where cholesterol, cellular waste, calcium and other fatty substances are deposited along the lining of artery walls in a person's body. These sticky, yellowish deposits, known as plaque, build up over time, hindering blood flow.

Also known as hardening of the arteries, atherosclerosis often starts early in life and progresses slowly as a person ages. Atherosclerosis typically affects medium and large arteries in the body.

Many scientists believe that damage to the endothelium, the innermost layer of the artery, is where atherosclerosis begins.

Damage to the endothelium allows plaque to build up along the lining of arterial walls, and as it does, blood flow is constricted and the supply of oxygen to the body is decreased.

Plaque can rupture and cause blood clots (thrombus). These blood clots can break away and enter the bloodstream, lodging in another part of the body, sometimes completely blocking blood flow (embolus).

Fatty embolisms that block blood flow to the heart cause a heart attack. If they block blood flow to the brain, they cause a stroke. If blood flow to the arms and legs is reduced, it can cause a person to have difficulty walking and eventually lead to gangrene.

Three proven causes of atherosclerosis are:

1) Elevated Cholesterol and Triglyceride Levels

Elevated levels of cholesterol and triglycerides in the blood cause damage to the endothelium.

Some cholesterol is necessary, and the body usually produces most of what it needs in the liver. The other source of cholesterol comes from animal fat and is known as LDL or "bad" cholesterol.

While our bodies need some LDL cholesterol, too much of it can raise cholesterol levels dangerously and put a person at risk for atherosclerosis / heart attack.

Foods that come from animals, i.e., chicken, eggs, dairy products, beef, and pork contain cholesterol. Foods from plants do not contain cholesterol.

More on Cholesterol:

2) High Blood Pressure

Blood pressure is the result of two forces. One is the pressure created by the heart pumping blood through the circulatory system. The other is the force of the resistance of the arteries as the blood flows through them.

When the heart pumps, it pushes blood through the larger arteries and on into the smaller blood vessels, called arterioles. The arterioles can constrict or expand, and when they do, the resistance of the blood flow is affected. The more difficult it is for the blood to flow, the higher blood pressure will be.

When high blood pressure goes untreated for a long time and the heart is forced to pump harder to get the blood to flow, the result is often an enlarged and weakened heart muscle. High blood pressure hurts the arteries and arterioles over time as well. They become scarred and hardened, putting a person at risk for atherosclerosis.

More on the Heart and Circulatory System:

3) Tobacco Smoke

Cigarette smoke aggravates both of the above risk factors for atherosclerosis.

  • Cholesterol: The toxins in tobacco smoke lower a person's high-density lipoprotein cholesterol (HDL or "good" cholesterol) while raising levels of low-density lipoprotein cholesterol (LDL or "bad" cholesterol).
  • Nicotine and Carbon Monoxide: The nicotine and carbon monoxide in cigarette smoke damage the endothelium, which sets the stage for the build-up of plaque.
  • High Blood Pressure: While cigarette smoking won't cause high blood pressure, if a smoker has hypertension, smoking can increase the risk of malignant hypertension, a dangerous form of high blood pressure. Smoking is hard on the heart.

    Harmful Chemicals in Cigarettes -- A to Z

    Smokers face an increased risk of atherosclerosis, heart attack and stroke.

    If you are a smoker and you're thinking about quitting, I have good news for you, and it is this:

    It is never too late to quit smoking.

    Regardless of your age or how many years you've smoked, research has shown that your body will begin the healing process within 20 minutes of your last cigarette.

    Within one year of quitting smoking, coronary artery disease drops to half that of a smoker. Between 5 and 15 years of quitting, coronary disease and stroke risk drop to that of nonsmokers.

    Quit Smoking Help


    National Institutes of Health. Atherosclerosis. Accessed February, 2011.

    Continue Reading