Diet in the epidemiology of coronary heart disease

The nutritional epidemiology of cardiovascular disease

A basic review of the extensive literature focusing on the major risk factors of atherosclerotic coronary heart disease and stroke, i.e., elevation of blood lipids related to diet, blood pressure elevation, and genetic factors using the traditional epidemiological model of interaction between host, agent, and environment, has strongly supported the concept that diet and particularly saturated fat and/or cholesterol are significant contributors to the elevation of blood lipids, especially cholesterol, and contribute importantly to the premature development and mortality of atherosclerotic coronary heart disease. Certainly genetics exert an important impact on this process. To date it remains unclear whether or not major changes in the dietary pattern of huge population groups can be practically effected. The minor dietary modifications so far studied in the average atherosclerosis-prone population cannot be anticipated to make a major dent in the epidemic proportions of atherosclerotic coronary heart disease. It is quite clear that prospective preventive medicine must be implemented at a very early age in the pediatric age group, in which atherosclerosis is now recognized by many as the number one pediatric problem. Tremendous biochemical advances have provided new insights in knowledge regarding the transport of blood lipids, particularly cholesterol, and the regulatory mechanisms at the cellular level for cholesterol under normal circumstances and in the genetic influenced hyperlipidemias (TABLE 4). A bright future lies ahead for the reduction of the epidemic of atherosclerosis which could be greatly enhanced by a greater personal responsibility for health care and a much more careful and prudent diet selection and exercise managment.

The cardiologist's responsibility for preventing coronary heart disease

The recent increase in coronary heart disease is real and the causes must mainly be environmental. Consequently the condition should largely be preventable. The application of what is already known is likely to be a far more effective way of reducing the mortality rate than all attempts at palliative treatment, but vigorous action will be necessary. Much greater sums are being expended on coronary-care units and cardiac surgery than in preventing the need for them, although there is little evidence that they have significantly lowered the over-all mortality rate. Conventional treatment is immensely expensive. Prevention could in the long run be much cheaper. Cardiologists on their own are unlikely to succeed in a program of prevention. They need the help of many others, including community nurses, nutritionists, public health workers, sociologists, and of course general practitioners, but they have responsibility for leadership and for providing background knowledge. For the detection of certain risk factors, health examinations are necessary and should be part of general practice. Also, advice is best given on an individual basis. The chief-known risk factors (hyperlipidemia, hypertension, smoking, physical inactivity) could be controlled. CHD occurs in adults but atherosclerosis starts many years before. Prevention should begin with appropriate infant feeding, whenever possible with breast milk, and continue into childhood, when habits are formed and attitudes to life can best be influenced. It should be possible to bring up children virtually free from risk factors. It may never be possible to prove the effectiveness of such a multifactorial program by prospective controlled intervention studies, but the evidence indicates strong probability. The stakes are too high to delay action any longer. Physicians daily give advice in areas where the evidence is much less certain. Such a program for the control of coronary artery disease is urgently needed and could become one of the most rewarding activities for the medical profession.