There are dozens of risk factors for heart disease. Those cited most often by medical orthodoxy include high blood cholesterol, smoking, lack of exercise, stress and overweight. A high level of cholesterol in the blood is a mild risk factor for individuals with familial hyper-cholesterolemia (cholesterol levels chronically above 350 mg/dl) but for most of us, there is no greater risk of heart disease between cholesterol levels that are "high" (over 300 mg/dl) and those that are "low" (under 200 mg/dl).
One factor of apparent importance is smoking, which has been associated in many studies with an increased risk of coronary mortality, even after correction for other risk factors. It is easy to speculate on the mechanism by which smoking causes heart disease. Exposure to fumes containing free radicals may promote the growth of atherosclerotic plaques. Perhaps chronic carbon monoxide intoxication limits the heart's utilization of oxygen.
But the picture is more complex than simple cause and effect. In a multi-year British study involving several thousand men, half were asked to reduce saturated fat and cholesterol in their diets, to stop smoking and to increase the amounts of unsaturated oils such as margarine and vegetable oils. After one year, those on the "good" diet had 100 percent more deaths than those on the "bad" diet, in spite of the fact that those men on the "bad" diet continued to smoke.2 In a study of Indians from Bombay and Punjab, researchers found that those from Punjab had one-fifth the number of heart attacks even though they smoked eight times more cigarettes.3 And while smoking was widespread at the turn of the century, myocardial infarction was not. This suggests that there may be factors in traditional diets that protect against the negative effects of smoking. It also raises the question of whether additives now used in cigarette paper and filters and changes in the curing process itself have exacerbated the harmful effects of cigarette use.
Perhaps the association between smoking and heart disease is really an association with some other factor—stress, biochemical imbalances, nutrient deficiencies—that creates the desire or the need to smoke. Often when people quit smoking they become nervous and overweight, which may seem a bad bargain of one risk factor in exchange for two more.
Regular physical activity is one of the few risk factors that has proved consistent. In all studies, regular physical activity is inversely associated with mortality from CHD, and physical activity is the only factor that has shown dose-response in the trials. Common sense tells us why exercise may be beneficial. When we exercise, our heart beats more rapidly, the arteries widen to provide more oxygen and arterial blood flow improves.
Lack of exercise may also be a risk factor because it is a marker for something else that is the true cause. People who are overweight, for example, are less inclined to exercise. Prosperous people who have leisure time are more likely to exercise than those who must work long hours to make ends meet—and we know that heart disease in westernized nations is more prevalent among the poor.4 Dietary factors may make people less inclined to exercise. An interesting finding in the Framingham study was that those who ate the most saturated fat, the most calories and the most cholesterol were the most physically active.5 They also weighed the least and had the lowest levels of serum cholesterol!
Common sense also tells us why overweight may be a risk factor. People who are overweight are less inclined to exercise. They probably eat large quantities of refined foods that provide lots of calories but little nourishment. They may have biochemical imbalances that contribute not only to overweight but also to some of the many aspects of heart disease, such as the tendency to form blood clots.
Many doctors have noticed that heart attack strikes in the months just after severe emotional trauma—loss of a spouse or close friend, bankruptcy, layoff or disappointment. We know that grief changes many aspects of the body chemistry, making us more vulnerable to all sorts of diseases—not just heart disease but also cancer, allergies, tuberculosis and depression. But mankind has always suffered loss and grief. The question is why these traumas cause heart attacks today but did not in 1900.
Although the known risk factors may not be the underlying causes, it makes sense to exercise regularly, to avoid smoking, to maintain an appropriate body weight and to minimize stress. Unfortunately, avoidance of these risk factors is no guarantee. We all know of slim, nonsmoking, active, successful individuals who have developed heart disease—including athletes who have keeled over while jogging. And stress cannot always be avoided. All of us face loss and challenge. The question is, how do we fortify the body to deal with stress in a way that minimizes its impact on the physical body?
How can we protect ourselves against heart disease?
One factor of apparent importance is smoking, which has been associated in many studies with an increased risk of coronary mortality, even after correction for other risk factors. It is easy to speculate on the mechanism by which smoking causes heart disease. Exposure to fumes containing free radicals may promote the growth of atherosclerotic plaques. Perhaps chronic carbon monoxide intoxication limits the heart's utilization of oxygen.
But the picture is more complex than simple cause and effect. In a multi-year British study involving several thousand men, half were asked to reduce saturated fat and cholesterol in their diets, to stop smoking and to increase the amounts of unsaturated oils such as margarine and vegetable oils. After one year, those on the "good" diet had 100 percent more deaths than those on the "bad" diet, in spite of the fact that those men on the "bad" diet continued to smoke.2 In a study of Indians from Bombay and Punjab, researchers found that those from Punjab had one-fifth the number of heart attacks even though they smoked eight times more cigarettes.3 And while smoking was widespread at the turn of the century, myocardial infarction was not. This suggests that there may be factors in traditional diets that protect against the negative effects of smoking. It also raises the question of whether additives now used in cigarette paper and filters and changes in the curing process itself have exacerbated the harmful effects of cigarette use.
Perhaps the association between smoking and heart disease is really an association with some other factor—stress, biochemical imbalances, nutrient deficiencies—that creates the desire or the need to smoke. Often when people quit smoking they become nervous and overweight, which may seem a bad bargain of one risk factor in exchange for two more.
Regular physical activity is one of the few risk factors that has proved consistent. In all studies, regular physical activity is inversely associated with mortality from CHD, and physical activity is the only factor that has shown dose-response in the trials. Common sense tells us why exercise may be beneficial. When we exercise, our heart beats more rapidly, the arteries widen to provide more oxygen and arterial blood flow improves.
Lack of exercise may also be a risk factor because it is a marker for something else that is the true cause. People who are overweight, for example, are less inclined to exercise. Prosperous people who have leisure time are more likely to exercise than those who must work long hours to make ends meet—and we know that heart disease in westernized nations is more prevalent among the poor.4 Dietary factors may make people less inclined to exercise. An interesting finding in the Framingham study was that those who ate the most saturated fat, the most calories and the most cholesterol were the most physically active.5 They also weighed the least and had the lowest levels of serum cholesterol!
Common sense also tells us why overweight may be a risk factor. People who are overweight are less inclined to exercise. They probably eat large quantities of refined foods that provide lots of calories but little nourishment. They may have biochemical imbalances that contribute not only to overweight but also to some of the many aspects of heart disease, such as the tendency to form blood clots.
Many doctors have noticed that heart attack strikes in the months just after severe emotional trauma—loss of a spouse or close friend, bankruptcy, layoff or disappointment. We know that grief changes many aspects of the body chemistry, making us more vulnerable to all sorts of diseases—not just heart disease but also cancer, allergies, tuberculosis and depression. But mankind has always suffered loss and grief. The question is why these traumas cause heart attacks today but did not in 1900.
Although the known risk factors may not be the underlying causes, it makes sense to exercise regularly, to avoid smoking, to maintain an appropriate body weight and to minimize stress. Unfortunately, avoidance of these risk factors is no guarantee. We all know of slim, nonsmoking, active, successful individuals who have developed heart disease—including athletes who have keeled over while jogging. And stress cannot always be avoided. All of us face loss and challenge. The question is, how do we fortify the body to deal with stress in a way that minimizes its impact on the physical body?
How can we protect ourselves against heart disease?
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