The hypothetical epidemic of coronary heart disease and atherosclerosis.

Accurate usage of the term 'epidemic' is important scientifically and it should ideally be used to mean only contagious diseases, not used loosely or emotively to mean non-infectious diseases, particularly coronary heart disease, which is a non-specific complication of many diseases. It should not be used as a surrogate term for atherosclerosis of indefinite severity. An epidemic of atherosclerosis is impossible, there being no variation in prevalence because the disease is ubiquitous. Moreover, vital statistics are too unreliable to determine the existence of an increase or decline in coronary heart disease. A coronary heart disease epidemic could be due to an increase in non-atherosclerotic coronary heart disease or increased severity of atherosclerosis. The former has not been studied and the latter would cause a shift to the left in age distribution and is inconsistent with the fall in 'all cause' and stroke mortality rates whilst coronary heart disease mortality allegedly increased alarmingly. A coronary heart disease epidemic, having no scientific basis, negates any reason for the sustained search for a speculative causative environmental factor.