University of Minnesota

Martti Karvonen on the Finnish Mental Hospital Study

A remarkable Cross-over-design diet-disease study was begun in the 1950s in Finnish mental hospitals as described here by a pioneer principal investigator, Martti Karvonen, who was also a leader in the Seven Countries Study and the North Karelia Study.

The Finnish Mental Hospital Study

The ideas for the study were jointly developed by Osmo Turpeinen, Paavo Roine, Maija Pekkarinen, and myself. Matti Miettinen, a young specialist in internal medicine, was recruited to conduct and lead the clinical aspects of the study. The design of the study was to change the diet of the patients in one large mental hospital with regard to its fat content by substituting butter and milk fat with margarine containing unhydrogenated, polyunsaturated fatty acids, whereas the diet of another mental hospital, the “control hospital” would be left unchanged, representing the ordinary Finnish diet of that time with a very low P/S ratio (less than 0.20).

Such special margarines were not yet available in the 1950s and we had difficulties in getting the margarine industry to help us get such margarines. Finally we, however, got in touch with a small . . . Factory, OTK margarine factory, which had back-up of the large, internationally recognized Dutch margarine industry, and with their help we got the margarine needed to change the dietary P/S ratio to about 1.5 in the experimental hospital.

Positive attitudes toward the trial of the chief physicians of the mental hospitals (Risto Elosuo and Erkki Paavilainen) and their other personnel was, of course, of decisive importance in getting this long-term trial started and finally completed.
We had, of course, initially the highest cardiovascular disease rates in Europe and in the whole world. But our own Finnish epidemiological research results from participation in the Seven Countries Study, the work of the Finnish Heart Association to give publicity to the findings and possibilities for prevention by lifestyle changes, and the publicity around the success of the North Karelia project have been the most important contributors to the ‘snowball phenomenon’ leading to these favourable [national] developments during the last decades.” (Martti Karvonen)