Bad Ldl Cholesterol Causes Heart Disease or Heart Attack, Stroke, High Blood Pressure, Atherosclerosis

Bad cholesterol, or Low Density Lipoprotein (LDL), is the major contributor to hypertension and heart disease, because bad cholesterol and excess fat form into plaques that block or clog arteries, leading to atherosclerosis, stroke, high blood pressure and heart attack.  Heart disease and (bad LDL) cholesterol have long been enjoying an illicit, adulterous love affair, as it were, producing heart disease as its eldest offspring.  Dr. Ancel Keys (deceased), who gained the sobriquet “Mr. Cholesterol” was the first to discover the link between bad cholesterol and heart disease in the 1950s. 

Featured on the cover of Time Magazine, Dr. Keys recommended cutting on saturated fat and opting for more polyunsaturated fats to lower cholesterol levels.  He introduced the assumptions about the relationship between diet, energy expenditure, metabolic rates and health.

Cholesterol Defined

Cholesterol is a soft, waxy substance, produced from the fats we eat.  Cholesterol isn’t necessarily a villain.  The liver – and even the intestines and the skin – manufactures cholesterol because the body needs it to build cell membranes, sex hormones, vitamin D and fat-digesting bile acids.  The liver’s source for cholesterol is dietary fat.

Two Types of Cholesterol

Researchers discovered that one key to heart health is the balance between the so-called bad cholesterol (low density lipoprotein or LDL) and good cholesterol (high density lipoprotein or HDL).  Furthermore, researchers have found that the higher the HDL and the lower the LDL ( which should be the ideal balance, observed in hunter-gatherer societies), the lower the risk of blocked coronary arteries and heart attack.

Low Density Lipoprotein Cholesterol is the Culprit

Packed with fats, LDLs navigate the blood stream, feeding liquefied cholesterol to the cells.  An accumulation of LDL in the blood starts to block arteries, which overtime can create clogs.  The proliferation of LDL in the bloodstream is the foundation of heart-threatening plaques.  These plaques – a mixture of fat, cholesterol, calcium and other cellular waste products – narrow coronary arteries, thus lesser blood flows to heart muscles.

New research suggest that one type of LDL – small, dense LDLs – is particularly lethal.  These tightly packed particles are easily damaged by free radicals in the bloodstream.  These damaged LDLs penetrate arterial walls with more ease, laying the foundation for plaque buildup, increasing the risk for atherosclerosis.

How Bad Cholesterol Accumulates

A diet high in saturated fats, and the lack of exercise due to the pervasive nature of a sedentary lifestyle associated with today’s I.T. and T.V. generation, can prompt the liver to manufacture more LDLs.  Furthermore, a diet low in monounsaturated fats, plus a sedentary lifestyle, depletes helpful HDLs.  Smoking and diabetes also increase LDL levels and decrease HDL.

Recent studies have shown that LDL levels should be much lower, and HDL levels much higher, for optimum health, especially for women, who have naturally higher HDL levels prior to menopause.

The bottom line is that high levels of LDL in the bloodstream increases abundantly the risk for atherosclerosis.  Lower levels reduce the risk significantly.  A research conducted by Professor Simon Capewell at the Liverpool University suggests that reducing (total) cholesterol from 5.8 mmol/l to 5.2 mmol/l on average can save up to 25,000 lives each year from the risk of heart attack.

Cholesterol levels

Here is a table of cholesterol levels and their corresponding assessment:

Less than 5 mmol/l – ideal

5.2 mmol/l – 6.4 mmol/l – moderately high

Above 6.5 mmol/l – high

The ideal balance of cholesterol levels should be, much higher HDL levels, and much lower LDL levels.  This balance reduces the risks for atherosclerosis and heart disease, leading to a healthier heart.

Sources:

“Ancel Keys”The American Physiological Society Website.  Article on Ancel Keys.  (Accessed 09/26/2010)

“30 minutes a Day to a Healthy Heart” Reader’s Digest Association Limited. London. 2005. 319 pages. Hardbound.