19 - The Secular Decline in the Coronary Heart Disease Epidemic

Summary

The announcement for this reversal in the long-term upward trend [of coronary heart disease mortality] was received with great astonishment, both in the United States and in other countries.

No one has yet established a convincing fit of trends for any risk factor with cardiovascular mortality trends.

The Secular Decline In The Coronary Heart Disease Pandemic

The great twentieth-century coronary heart disease pandemic, which killed millions of persons in westernized countries, abated after 1960 and continued to wane for the remainder of the century. Its rise and fall has usually been explained by population-wide changes in personal risk factors, which include excessive animal fats and cholesterol in the diet, obesity, smoking, sedentary living, lack of physical exercise, and stress. According to this theory, a meaningful decline in coronary heart disease rates occurred after the risk factors were modified in large numbers of persons.

From one perspective, it is inconceivable that an international pandemic of any disease could be caused or eliminated by changes in personal behaviors. The millions of persons affected by the coronary heart disease pandemic lived in two dozen countries with different social and economic structures, customs, traditions, diets, and work and recreational activities. Such diversity could never produce identical patterns of personal behavior that materialized and diminished simultaneously in all of the countries. Furthermore, personal behaviors have never been considered responsible for the great pandemics of the past, such as the nineteenth and early twentieth centuries pandemics of cholera, tuberculosis, and influenza. All great pandemics have been explained by singular combinations of social, economic, and technological changes, usually including new patterns of transportation that permitted the spread of the disease across countries and continents.

From another perspective, the factors that produced great pandemics were never the same as those that produced different rates of the disease in specific groups. For example, before, during, and after the coronary heart disease pandemic, the disease was more prevalent in men, lower socio-economic groups, and hypertensive persons. Thus these factors could not have caused the pandemic to develop or diminish.

To demonstrate a correlation between risk factor changes and the decline in coronary heart disease mortality rates, it is necessary to compare the date of onset of the decline in coronary heart disease rates to trends in the prevalence of risk factors.