Martti Karvonen

Quotes

Origins of CVD Epidemiology in Finland

I met with Ancel Keys for the first time in the beginning of the 1950s. Two international meetings on nutrition were arranged in Europe during those years. These were not ordinary scientific conferences but meetings to which national health authorities sent their representatives and I participated in these conferences as a representative of Finland. Ancel Keys participated in the first of these two meetings as an external expert. The main topic discussed at these meetings was the role and the optimal need of main nutrients, carbohydrates, proteins and fats for the maintenance of good nutritional state and health. There was already a reasonable agreement on the need of calories, carbohydrates and proteins, but ideas about fats were still rather hazy. Ancel Keys was already at that time developing his ideas for studies on the relationship of nutrition and cardiovascular disease. I told him that coronary heart disease is very common in Finland and that we have a peculiar regional difference, East Finland having a much higher coronary mortality than West Finland. (3)

[The information I] gave to Ancel Keys was based on the PhD thesis work of Väinö Kannisto, a demographer, published in 1949, although the study was mainly based on mortality statistics of the 1930s.. In any case, he was so excited about it that he proposed that we should do a field study in Finland to identify possible factors that might explain the high coronary heart disease mortality in Finland and its regional difference. I then started the preliminary planning of the study and we chose a number of communities from North Karelia and southwestern Finland as study communities. The majority of the male population of North Karelia, where the large part of the province is covered by woods, were small farmers who worked for the most part of the year in heavy lumber work, whereas the southwestern communities were mainly grain farming communities with bigger farm sizes.

In 1956 Ancel Keys came to Finland with Flaminio Fidanza, Professor of Biochemistry at the University of Perugia, Italy, and I took them to both North Karelia and southwestern Finland to see the study communities. Flaminio Fidanza actually stayed in Finland during these pilot studies to supervise the biochemistry work. (4)

(The famous story of the 1956 visit of Ancel Keys, Flaminio Fidanza and Martti Karvonen, told in several versions, originates from that visit. Martti Karvonen drove them in his small car to North Karelia to show them the study communities. In Ilomantsi the local general practitioner, Dr Tauno Koistinen showed them the small community hospital [infirmary] which had two rooms [wards], one for men and another for women. According to the memoirs of Ancel Keys, the distribution of the diagnoses in the six-bed room for men was as follows: one had pneumonia, one had liver disease, one had been bitten by a bear, and the other three had coronary heart disease. In amended versions of the story, the number of men bitten by a bear has been two or three. Another version of the story is that having seen a man bitten by a bear the Italian Professor became so scared that he got back to Helsinki and established his cholesterol laboratory instead of in Ilomantsi at the Institute of Occupational Health in Helsinki. But according to Ancel this part of the story is not true). (5)

Conflicting Early Views of CVD Prevention

MK: In general, at that time they were not very much interested about possible causes of coronary heart disease. It was considered as a disease to which very little could be done, even in terms of treatment, and even less with regard to prevention. But among the Finnish cardiologists of that time there was one important exception, Professor Pauli Soisalo, the Chief Physician of the Department of Internal Medicine of the Kivelä Hospital, the largest Helsinki city hospital. He had made several visits to the United States and learned about the American Heart Association and its work and about early ideas of prevention. He was one of the key persons in the establishment of the Finnish Heart Association in 1955 as the second oldest Heart Association in the whole world.

KP: As you know, my own mentor in cardiology, Professor Pentti Halonen, who introduced cardiac catheterisation and modern clinical cardiology to Finland, did not believe in the possibilities of prevention of coronary heart disease at that time and not even later. He actually was rather strongly opposed to activities aiming at prevention and found strong allies among his cardiologist friends in other countries, among them Professor John McMichael and Professor Jack Shillingford in England and Professor Lars Werkö in Sweden. (9)

MK: My problem was that I was not a cardiologist and had come to this field from the field of physiology. Thus, no wonder that when the results of our pilot studies and then later reports from the Seven Countries began to become published, the cardiological community in Finland did not look at me with “a good eye” and did not pay much attention to our results. (10)

The Finnish Mental Hospital Trial

The plan for the Finnish Mental Hospital Study was really “home-made.” Professor Osmo Turpeinen was the principal investigator of the trial and also in the development of the trial design. He was about 10 years older than me. I learned to know him during the first part of the Second World War, the so-called Finnish winter war in 1939-1940. 1 was at that time a medical student and got an order to go to work in an army laboratory on war gases and that laboratory was led by Osmo Turpeinen. Fortunately the knowledge of war gases developed at that laboratory was not needed in the war. After the war, in 1947, Osmo Turpeinen became appointed as Professor of Biochemistry and Physiology of the newly established Veterinary High School in Helsinki… 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 margarine industry to help us in getting such margarine. Finally we, however, got in touch with a small margarine factory, OTK margarine factory which had a back-up of a 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. . . after the first trial period of 6 years, . . trial design included that the diets were switched for the next 6 years, the “experimental diet” hospital then getting the ordinary Finnish diet, and the original “control hospital” getting the “experimental diet.” In the world of that time such studies could still be done, because no convincing information was available about. . . changes in dietary fats on the occurrence of coronary heart disease events. (11)

The North Karelia Project

When the first Finnish results of the Seven Countries Study had become published and also known by the public through the information spread by the Finnish Heart Association, radio and the newspapers, it was natural that people began to ask whether something could be done to improve the poor cardiovascular health situation, particularly the extremely poor cardiovascular health of people in North Karelia. As has been told in the published reports, in response to the report of the 10-year results of the Finnish part of the Seven Countries Study in 1970, the Regional Governor of North Karelia, Esa Timonen invited all North Karelian members of the Finnish Parliament and representatives of official and voluntary organizations to form a pressure group and to sign a petition for the state of Finland to do something to reduce the cardiovascular health problem in North Karelia. This petition was then presented in the beginning of the year 1971 by a North Karelian delegation led by the Governor to the Finnish Government, National Board of Health, the Finnish Medical Research Council, and the Finnish Heart Association.

The Finnish Heart Association then took the next practical step and supported the planning of a community-wide cardiovascular disease prevention project. In September 1971 a planning seminar with participation of international experts (Zdenek Feijfar, WHO, Geneva, Zbynek Pisa, WHO, Copenhagen, Jerry Morris, UK, Henry Blackburn, USA) was held in Joensuu. Young Pekka Puska was appointed as a leader of the project and that was in many ways a wise decision. His enthusiasm and good capability for leadership and interaction with key people in the community proved to be decisive for the success of the project (The history and the experience from and outcomes of the North Karelia project have been described in detail in Puska P, Tuomilehto J, Nissinen A, Vartiainen E (eds): The North Karelia Project. 20 year results and experiences. Yliopistopaino, Helsinki 1 995). (14)

The Decline in Coronary Disease

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 developments during the last decades. Of course, improved management of already established cardiovascular disease has played also its role, particularly in more recent decades. (16)