By Hans R. Larsen, MSc ChE :Cardiovascular disease is the major cause of death in the United States; it claims more lives than all other diseases combined(1). Worldwide it is estimated that more than 12 million people die every year from cardiovascular disease(2).
What is cardiovascular disease?
Cardiovascular disease involves the heart and its two networks of blood vessels, the system which circulates the blood throughout the body and the system which circulates the blood through the lungs.
The heart, apart from what other mythical and emotional characteristics we may ascribe to it, is basically a living pump. Its failure, for whatever reason, usually means instant death. The heart is one of the hardest working organs in the body; it contracts and expands about 100,000 times every day. It supplies a blood vessel network 96,000 kilometers long and pumps in excess of 10,000 liters of blood around the body every single day.
The heart pumps returning "used" blood through the lung capillaries where waste gas, primarily carbon dioxide, is expelled and fresh oxygen is taken up by the blood. From the lungs the now oxygenated, bright red blood is pumped through the aorta into the smaller arteries, the capillaries, where the actual nutrient and oxygen exchange with individual body cells takes place, and then back to the heart through the veins. Immediately after exiting from the heart the aorta branches off into the right and left coronary arteries which supply the heart itself with fresh blood and the nutrients it needs. The coronary arteries are attached directly to the wall of the heart and are squeezed and expanded 100,000 times a day. This constant stress makes them especially vulnerable to damage and disease.
Coronary heart disease and stroke are the two major manifestations of cardiovascular disease. In the United States, about 500,000 people die every year from coronary heart disease and about 150,000 from stroke(3). The cost of treating cardiovascular disease with surgery and drugs now exceeds $115 billion a year in the United States alone(4). Cardiovascular disease is very much a disease of Western Civilization and its incidence varies from almost 1,000 deaths per 100,000 population in Hungary to less than a third of that in Japan(2).
Coronary heart disease strikes hardest at men in their mid-fifties while women usually are spared until about age 65(5). Coronary heart disease is also known as ischemic heart disease and its most common forms are myocardial infarction (heart attack) and angina pectoris (chest pain).
Conduction disturbances, valve malfunctions, and arrhythmias are other common manifestations of heart disease, but their significance pales in comparison with the impact of coronary heart disease. Stroke, intermittent claudication (a peripheral vascular disease) and macular degeneration (a leading cause of blindness involving the central part of the retina) are cousins of coronary heart disease and all have one common ancestor – atherosclerosis(3,5,6).
Atherosclerosis is a disease of the arteries in which fatty, often calcified deposits develop on the inside of the arterial walls and eventually cause blockages which lead to cardiovascular disease. Atherosclerosis is the result of the body’s attempt to patch up injuries to the inside of the arterial walls. These injuries come about because of weaknesses in the walls and because the walls are constantly exposed to mechanical stress induced by the heart’s pumping action. This stress is exacerbated by high blood pressure (hypertension) and chronic emotional stress(3,5,7).
Free radical activity also plays a major role in the development and progression of atherosclerosis both through the generation of oxidized, reactive lipoproteins (compounds of proteins and fats which serve as carriers for cholesterol) and through direct attacks on the DNA of the arterial wall cells(7-12).
The body attempts to repair the damage to the arterial walls by producing more smooth-muscle cells in the area of the injury; these cells in turn tend to accumulate cholesterol and oxidized lipoproteins and may also undergo calcification(3,5,10). As the deposits grow they narrow the inside opening of the artery and eventually create a blockage. If the blockage is in the coronary arteries angina pectoris may develop or a heart attack may occur. If it is in the brain, a stroke may be the result and if the blockage is in the legs intermittent claudication may occur.
It is interesting that cardiovascular disease is unknown among other mammals. Why are humans the only species afflicted with this disease? Nobel laureate Dr. Linus Pauling and Dr. Matthias Rath, MD, a German physician and leading expert in cardiovascular disease believe that the root of the problem is our inability to produce vitamin C. Only Homo Sapiens, primates and guinea pigs do not manufacture vitamin C internally. Drs. Pauling and Rath believe that cardiovascular disease is a form of early scurvy and that the vitamin C deficiency inherent in both diseases manifests itself by the development of fragile blood vessels lacking in collagen – the reinforcing rods of arteries. They also believe that we developed the artery wall repair mechanism thousands of years ago as a compensation for our inability to produce vitamin C and sufficient collagen to maintain strong, healthy arteries which would not be prone to tears and injuries(2,13,14).
Many scientific studies have shown that a lack of vitamin C and other antioxidants increases the risk of heart disease and stroke(2,15-23). Other major risk factors for cardiovascular disease are smoking, a high level of cholesterol and lipoproteins, diabetes, hypertension (high blood pressure), obesity (especially around the abdomen) and lack of exercise(3,5,24,25,26). Genetic predisposition can also be a factor in the development of heart disease, but some experts downplay its importance(3,5,25).
Excessive exposure to free radicals generated through contact with pesticides, chlorinated water, air pollutants and other toxic chemicals is a strong risk factor for cardiovascular disease(7,10). Chronic emotional stress is also a significant risk factor and acute emotional or physical stress may precipitate a heart attack(3,24,27,28). Stress not only raises the blood pressure and constricts the arteries, it also generates large quantities of adrenalin which the body converts to adrenochrome – a potent free radical(29).
The role of alcohol in the development of cardiovascular disease is controversial. Recent research has shown that consumption of moderate amounts of wine, especially red wine, actually reduces the risk of developing heart disease; other studies dispute this. The consensus of opinion now seems to be that a couple of glasses of wine or a beer or two a day will not promote heart disease and may even help to prevent it. Heavy drinking, however, is still considered a potent risk factor for heart disease(30-33).
Iron has recently been implicated in heart disease(34,35). Researchers at Harvard University now conclude that it is not the overall iron intake which increases the risk of heart attack, but rather the intake of heme iron as found in red meat. The Harvard researchers found that men who ate beef four times or more per week had a 38% greater risk of having a heart attack than did men who ate beef once per month or less(36). More recent studies show that the body is remarkably efficient in keeping the blood’s iron content within safe limits(37).
Cholesterol is an important intermediary in the production of many vital hormones. The liver supplies all the body’s needs (about 3000 mg/day) and any excess dietary intake is unnecessary and harmful(24,25).
A high overall cholesterol level and a high level of LDLs (low density lipoproteins) are strong risk factors for cardiovascular disease in men. One recent study found that men with cholesterol levels higher than 6 mmol/l (240 mg/dl) have a three times higher risk than men with a level below 5 mmol/l (200 mg/dl)(3). Another study found that men who had a high cholesterol level in their youth are twice as likely to develop heart disease as are men with a low to normal level(38).
Cholesterol risk factors are different for women. The high density lipoprotein (HDL) level and the level of triglycerides are far more important risk factors for women than are total cholesterol and LDL levels. Women with low levels of HDL have a three times higher risk of dying from cardiovascular disease than do women with higher levels. Women with a low level of HDL and high levels of triglycerides have a death rate almost eight times greater than women with normal triglyceride levels and low HDL levels(39,40).
Recent research has shown that a high level of the amino acid, homocysteine, in the blood increases the risk of cardiovascular disease very significantly(41-44). Finnish researchers have discovered that mercury is a potent initiator of heart disease and other researchers have found that the risk rises with the number of amalgam tooth fillings(45). The Helicobacter pylori bacterium has also been implicated in the development of coronary heart disease(46).
The prevention of heart disease and stroke is synonymous with the prevention of atherosclerosis. Atherosclerosis can be prevented by developing strong artery walls, by controlling the factors which cause injuries to them and by minimizing the level of fats, lipoproteins, cholesterol and homocysteine in the blood.