Understanding cholesterol

Cholesterol is in many ways considered a dirty word. While cholesterol is too complex to categorize so easily, the widely known complications of high cholesterol make it easy to generalize cholesterol as something detrimental to human health.

But there’s more to cholesterol than meets the eye, and understanding this waxy substance can help men and women get a better idea of their overall health and what they need to do to be even healthier.

Where does cholesterol come from?

Cholesterol is produced by the body, but also comes from the food you eat. The human body makes all the cholesterol it needs and circulates that cholesterol through the blood. But foods, including meat, certain dairy products and poultry, also contain cholesterol, and the liver actually produces more cholesterol if you eat a diet that’s high in saturated and trans fats.

Why is cholesterol potentially dangerous?

According to the National Heart, Lung and Blood Institute, high blood cholesterol is a major risk factor for heart disease. If your body has too much cholesterol in its blood, that excess cholesterol can form plaque in the walls of your arteries, gradually causing a hardening and narrowing of the arteries.

Narrow arteries slow blood flow to the heart, which needs both the blood and the oxygen that blood carries in order to function at full strength. If plaque buildup in the arterial walls slows or blocks off that blood flow, a heart attack may result.

Bad vs. Good?

Many people are now aware that cholesterol is widely categorized as “bad” or “good,” but many of those same people may not know why that distinction is so important. 

Cholesterol does not dissolve in the blood, so it must be transported through the bloodstream by carriers known as lipoproteins. There are two types of lipoproteins that perform this function: low-density lipoproteins, or LDL, and high-density lipoproteins, or HDL.

LDL is what’s commonly referred to as “bad” cholesterol because it contributes to the buildup of plaque, the thick and hard deposits that can line the arterial walls and impede blood flow. HDL is the “good” cholesterol, as it helps remove LDL from the arteries. According to the American Heart Association, experts believe HDL gathers LDL before carrying it away from the arteries and back to the liver, where it is ultimately broken and down and passed from the body.

Healthy levels of HDL can protect against heart disease and stroke, while low levels of HDL are considered a major risk for heart disease.

What affects cholesterol levels?

Cholesterol levels are affected by lifestyle choices you can control and additional factors you cannot.

• Diet: Diet is entirely within your control, so bad cholesterol levels that increase because of your diet are entirely preventable. A diet that’s high in saturated fat is unhealthy, and the AHA recommends a diet that emphasizes fruits, vegetables, whole grains, low-fat dairy products, poultry, fish, and nuts. Avoid red meat as much as possible and steer clear of sugary foods and beverages.

• Weight: Weight is another controllable risk factor for high cholesterol. Being overweight is a risk factor for a host of ailments, including high cholesterol and heart disease. Losing weight can lower LDL while increasing HDL, providing the best of both worlds.

• Exercise: Regular physical activity can lower LDL and raise HDL levels. The AHA notes that 40 minutes of aerobic exercise performed at moderate to vigorous intensity three to four times per week is enough to lower LDL and high blood pressure. Inactivity, on the other hand, is a major risk factor for heart disease.

• Age: Cholesterol levels rise as men and women age, which only highlights the emphasis men and women must place on healthy lifestyle choices as they get older. You won’t be able to cease aging, but you can still make healthy lifestyle choices to combat the impact that aging has on your cholesterol levels.

• Gender: Gender is another uncontrollable factor that affects cholesterol levels. Before reaching the age of menopause, women have lower total cholesterol levels than men of the same age. But after they reach the age of menopause, women’s LDL levels typically rise.

• Heredity: High blood cholesterol can run in families, so your genes might just be influencing how much cholesterol your body is making.

How great is my risk of heart disease or heart attack?

The more risk factors, including high LDL levels and factors listed above, you have, the greater your risk of developing heart disease or having a heart attack. Those who already have heart disease are at greater risk for heart attack, and people with diabetes also have a more significant risk of developing heart disease.

Monitoring cholesterol levels and making healthy lifestyle choices can greatly reduce your risk of heart disease and heart attack. More information about cholesterol is available at www.heart.org and www.nhlbi.nih.gov. 

One Response to "Understanding cholesterol"

  1. Robert B   August 23, 2014 at 12:35 pm

    The importance of cholesterol in atherosclerosis is way, way overblown. Im 68, have familial hypercholesterolemia (obviously all my life), my so-called bad cholesterol (LDL) has always been extreme and has been above 500 for the last eight years, and my total cholesterol is above 600. YET by electron beam computed tomography (EBCT) my coronary arteries have zero calcification. My stress ultrasound of a few years ago showed my heart to be that of someone 20 years younger. My older sister, also FH, has no heart issues and our FH mother lived to 77 without ever having heart issues. Our mothers parents and grandparents all lived to be very old and, so far as we know, had no heart issues.

    I’ve asked many experts why it should be that some of us with extreme levels have no problems if cholesterol is causal to plaque buildup. They have no answers. Seems that ignoring this fact is much easier than attempting to understand the real causes of plaque buildup. Typically, I hear genetics or you are actually in real danger. Neither response is meaningful; everything is genetics, the real question is which genes and what are they doing? Nobody knows. As far as being in real danger, it is patently obvious that Im not in the kind of danger that afflicts the vast majority of heart disease victims: I dont have any of the plaque buildup that characterizes the disease. Saying I could have a heart attack would mean calcified plaque has nothing to do with it.

    Medical research seems to ignore the difference between associations and causation. Establishing causality is very difficult to do and requires a well-designed test method. Heart disease may, or may not, associate with elevated serum cholesterol. That definitely doesnt establish that serum cholesterol is causal. An example; baldness associates with increased risk of cancer and heart disease, but causes neither. Very few young men (under 20) are bald and very few much cancer or heart disease. Older men (above 30) include many who become bald, and older men also have most cancers and heart disease. Those statements are enough to establish association, but cannot establish causality.

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