What Causes Heart Disease? Part 1

Over the years, the debate on the role of cholesterol in the development of atherosclerosis and heart disease continues. When it was first proposed that high cholesterol increases heart attack risk, the medical establishment ridiculed the idea. However, decades of disputes changed the stance of the medical establishment, now the concept that high cholesterol causes heart attack has become a scientific consensus.
But many of today’s complementary medicine practitioners, who would have been early proponents of low-saturated fat diets, now question the association between cholesterol and vascular disease. This has become what is known as the "cholesterol controversy." The fact that confusion still exists over this straightforward medical principle helps explain why atherosclerotic disease remains today’s leading preventable killer.

While browsing through available scientific literatures and reviews on the topic, I came across an article by Dr. Larry Wilson, MD detailing important aspects in our understanding of the role of cholesterol in heart disease. The following is an exerpt of the article entitled "The Cholesterol Controversy" which I will present here in a three-part series.
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Medical authorities continue to recommend drugs and low-fat diets to reduce cholesterol. However, there is much more to the cholesterol story.

What Is Cholesterol?

Cholesterol is an essential body chemical, mostly synthesized in the liver. It is the precursor or raw material used to make the vital pituitary, adrenal and sex hormones. Cholesterol is also required to form vitamin D and bile acids. The liver makes about 2 grams of cholesterol daily, regardless of diet. Under stress, the body makes more cholesterol in order to make more adrenal or stress hormones.

Cholesterol is a mixture of compounds. These include high density lipoproteins or HDL, and low density lipoproteins or LDL. The latter contain lipoprotein-A, thought by some authorities to be important in the genesis of heart disease.

HDL, which is unoxidized cholesterol, is sometimes called ‘‘good cholesterol’’, while LDL, the oxidized form, is often termed ‘‘bad cholesterol’’. Blood laboratories often measure the ratio between the HDL and total cholesterol. 

Does Cholesterol Cause Heart Disease? 

The cholesterol theory of heart disease asserts that: 1) The risk of cardiovascular disease correlates with the serum level of cholesterol; and 2) Eating cholesterol-containing foods raises your cholesterol level. Let us explore this theory and alternative hypotheses in more detail.

About 100 years ago scientists noted that fatty deposits in the arteries often contain cholesterol. Of course, it was not known whether cholesterol deposits were the cause or the result of heart disease. Studies were done, including the large Framingham study, that found a definite correlation between high serum cholesterol levels and the risk of heart disease.

However, the picture is not as clear as it seems. The Framingham study found that LDL or oxidized cholesterol was more predictive of heart disease than total cholesterol. Also, the study could not correlate eating foods containing cholesterol and an increase in the blood cholesterol.

Furthermore, many studies from around the world do not support the simplistic idea that eating more cholesterol or saturated fat increases the risk of heart disease. In an interesting book, The Milk Of Human Kindness Is Not Pasteurized,(1) William C. Douglass, MD cites the following:

• The famous heart surgeon Michael Debakey analyzed 1700 patients with hardening of the arteries and found no correlation between blood cholesterol levels and the degree of atherosclerosis.(2)
• The New England Journal of Medicine reported that a group of Guinea natives whose diet is normally low in cholesterol were fed eggs to see how much the eggs would influence their cholesterol. There was no significant effect on cholesterol levels.(3)
• A study done by the American Cancer Society revealed that non-egg users has a higher death rate from heart attacks and strokes than egg users. This was a large and therefore convincing study involving over 800,000 people.(4)
• Eskimos living on a diet of mostly meat and fat, have low cholesterol levels (about 130mg) provided they stay on their native diet.
• The Masai tribe of Africa drink about 7 quarts of milk per day containing 60% saturated fat. Yet the average adult cholesterol level is 122.(5)
• The American Academy of Pediatrics is warning against the latest call for low cholesterol foods for children, since it is known that cholesterol is vital for children's growth

Many other studies show no significant effect on blood cholesterol from eating eggs or other cholesterol-containing foods. Several are reported in The New Vegetarian, by Gary and Steve Null. A study in France found that although butter consumption is much higher in Western than in Eastern France, the mortality from heart disease in Western France is almost half that of Eastern France.(6)

Before Western eating habits were introduced into the Eskimo population, they lived almost exclusively on animal meat and fat. Yet the incidence of heart disease was very low and cholesterol levels were below 200 mg.(7) Similar results were found in studies in the Soviet Union, India, and elsewhere.(8)(9)

The cholesterol theory of heart disease is very simplistic. It is like saying that duct tape wrapped around a damaged water hose is the cause of the hose damage. More likely, the tape - and the cholesterol - are the result of the damage, not the cause. In fact, two scientists, Brown and Goldstein, won a Nobel Prize in 1985 for their research into this theory. Cholesterol plaques are often there to protect a damaged artery. After all, a clogged artery is far preferable to a ruptured one. Elevated cholesterol is associated with heart disease, but may not be its cause.

References: 

1. Douglass, W.C., The Milk of Human Kindness is not Pasteurized, Copple House Books, Lakemont, Ga., 1985.

2. JAMA 189:655-59 (1964).

3. New England Journal of Medicine, 98:317 (1978).

4. Abrams, Journal Applied Nutrition, Vol. 32, #2, pp. 53-87.

5. Cardiovascular Disease of the Masai, Mann et. al.

6. Maclennan, R. and Meyer, F., Food and Mortality in France, The Lancet, 2 (1977): p. 133.

7. Ho, K.J. et al, Alaska Arctic Eskimo: Responses to a Customary High Fat Diet, American Journal of Clinical Nutrition, 25:1972, pp. 737-745.

8. Malhotra, S., Graphic Aspects of Acute Myocardial Infarction in India with Special Reference to Patterns of Diet and Eating:, British Heart Journal, 29:1967, pp. 337-344.

9. Prior, I.A. et al., Cholesterol, Coconuts, and Diet on Polynesian Atolls: A Natural Experiment, American Journal of Clinical Nutrition, 25:1972, pp. 737-745.