Etiology of Coronary Heart Disease

There are many theories today concerning the etiology of coronary heart disease, but much of current thinking can be summed up in two syllogisms. The first is, "Coronary heart disease is becoming more common; you cannot have coronary heart disease without atheroma: therefore, atheroma must be more common"; and the second, "Populations with high death rates from coronary heart disease have on the average a high serum cholesterol; atheroma contains cholesterol: therefore, a high serum cholesterol causes atheroma." Although in each of these arguments the premises are correct, the conclusions are questionable; and this is not surprising since the Aristotelian fallacy of the undistributed middle is committed in both.