Diet, fats and cholesterol
Part 1: Introduction
People are exercising like crazy, changing their diets, gulping supplements, and taking expensive drugs to lower their cholesterol. Yet none of this is making a dent in heart attack statistics. Why? Because they think that high cholesterol causes heart disease. But over the last half century study after study has shown that it doesn't. See an excellent paper on cholesterol and heart disease at Dr Barry Groves's Second-Opinions website
Atherosclerosis is a condition whereby arteries become blocked or partially blocked. This blockage effectively reduces the interior diameter of the artery thus restricting blood flow. The body then either increases the blood pressure, or oxygen transport around the body is lessened. If the coronary arteries are involved, the heart muscle is starved of the oxygen it needs. That results in the chest pain called angina. Eventually, as arteries become completely blocked either by the atherosclerosis or a blood clot, in a heart attack.
We are taught that atherosclerosis is caused by high levels of cholesterol in the blood - that it 'furs up' the heart's arteries. No it doesn't! In this section, we will explain what does.
Drs Michael Brown and Joseph Goldstein were awarded the 1985 Nobel Prize in Medicine for the discovery that atherosclerotic plaques are deposited in response to injury of the blood vessel wall. Where arteries pass through bony channels in the skull or through the heart muscle, they never develop atherosclerosis. This suggests that the stiffening action of atherosclerosis is actually a protective measure.
In 2002 the hearts of 11 young adults aged under 35 years, who had died within an hour of the onset of cardiac symptoms, were examined for the type of underlying plaque complication and the time of onset of clot formation. Only one of the eleven culprit lesions was rich in cholesterol. All lesions contained evidence of inflammation.
Doctors are beginning to recognise that inflammation is the major cause of athersclerosis - and ultimately CHD - not cholesterol. Raised cholesterol is merely an indicator that something is wrong.
But, if atherosclerosis is a protective response to some inflammation, the question is: What could cause that inflammation?
There are several possible answers.
- Oxidised LDL
- Bacterial or virus infection
- High levels of glucose in the blood
- High levels of insulin in the blood
What we eat affects all of these - but probably not in the way you think.
1. Brown MS, Goldstein JL. Michael S. Brown, MD and Joseph L. Goldstein, MD. 1985 Nobel laureates in medicine. J Investig Med 1996; 44: 14-23
2. Saul GD. Arterial stress from intraluminal pressure modified by tissue pressure offers a complete explanation for the distribution of atherosclerosis. Med Hyp 1999; 52: 349-351.
3. Henriques de Gouveia R, van der Wal AC, et al. Sudden unexpected death in young adults. Eur Heart J 2002; 23: 1433-1440
for more on cholesterol and heart disease, see Cholesterol-and-Health.org