Dietary Prevention of Coronary Heart Disease: The Finnish Mental Hospital Study

Turpeinen O [Proofessor Emeritus of Biochemistry, College of Veterinary Medicine, Hämeentie 57, 00550 Helsinki 55, Finland], Karvonen M J, Pekkarinen M, Miettinen M, Elosuo R and Paavilainen E. Dietary prevention of coronary heart disease: the Finnish Mental Hospital Study. International Journal of Epidemiology 1979, 8: 99–118. A controlled intervention trial, with the purpose of testing the hypothesis that the incidence of coronary heart disease (CHD) could be decreased by the use of serum-cholesterol-lowering (SCL) diet, was carried out in 2 mental hospitals near Helsinki in 1959–71. The subjects were hospitalized middle-aged men. One of the hospitals received the SCL diet, i.e. a diet low in saturated fats and cholesterol and relatively high in polyunsaturated fats, while the other served as the control with a normal hospital diet. Six years later the diets were reversed, and the trial was continued another 6 years. The use of the SCL diet was associated with markedly lowered serum-cholesterol-values. The incidence of CHD, as measured by the appearance of certain electrocardiographic patterns and by the occurrence of coronary deaths, was in both hospitals during the SCL-diet periods about half that during the normal-diet periods. An examination of a number of potential confounding variables indicated that the changes in them were small and failed to account for the considerable reduction in the incidence of CHD. It is concluded that the use of the serum-cholesterol-lowering diet exerted a substantial preventive effect on CHD.