When the dietary guidelines were devised in the 1970s/1980s one of the most important studies used to justify them was the investigation conducted in North Karelia, which is a province in Finland. Population studies were conducted between 1972 and 1992 to monitor blood cholesterol (TC), blood pressure (BP), height, weight and the incidence of smoking. Deaths were recorded (1).
Between 1972 and 1992, TC decreased by 13.0% in men and 17.6% in women; diastolic BP decreased by 9.2% in men and 13.3% in women. The prevalence of smoking decreased from 53% to 37% in men but increased from 11% to 20% in women.
During that period, the mean age standardised mortality from ischaemic heart disease (IHD) in men was 647/100,000 population, dropping to 289/100,000 in 1992. In women, the corresponding decrease was from 114/100,000 to 36/100,000.
It was claimed that these reductions in the mortality rates were due to a reduction in risk factors. For men, it was argued that this was due to the 13% decrease in TC that predicted a 26% decline in mortality from IHD, a 9.2% decrease in diastolic BP that predicted a 15% decline and a 16% decrease in smoking that predicted a 10% decline. Apparently this worked quite well for the first 10-12 years but after that the decline was even greater that the predictions.
For women, the actual decline was 68% but the change in risk factors could only predict a reduction of 49%. This was based on a decrease of 18% in TC that predicted a 35% decline, a decrease of 13% in diastolic BP that predicted a 31% decline and an increase in smoking of 9% that predicted an 11% increase.
Because the changes in risk factors seemed to explain the decline in the incidence of IHD it was concluded that:
“The findings of our study show that the population strategy for preventing ischaemic heart disease in Finland has been successful.”
The results of this study are frequently used to justify the many of the conventional health promotion strategies, especially TC lowering. Here are the conclusions of a paper written by a senior WHO official in 2002:
“The experiences and results of the North Karelia Project in Finland support the idea that a well-planned and determined community-based programme can have a major impact on lifestyles and risk factors, and that such a development really leads quite rapidly to reduced cardiovascular rates in the community. Furthermore, they demonstrate the strength of community-based approach in changing the people’s risk factors as well as give practical experience in organizing such activities.
The experiences also show that a major national demonstration project can be a strong tool for favourable national development. Experiences have actively contributed to a comprehensive national action with very good results. The decline in heart disease mortality during the last few years has been in Finland one of the most rapid in the world and the overall health of the adult population has greatly improved.
Active international collaboration with WHO and other agencies initially helped the North Karelia Project. Later on WHO has helped to apply elsewhere the approach and experiences of the North Karelia Project. As indicated earlier, numerous community-based projects and national demonstration programmes are under way in many countries of the world, particularly related to the WHO programmes. This development will ultimately help different parts of the world to start controlling the modern epidemics of non-communicable disease and tell us more about the usefulness of different intervention approaches in different cultural settings.” (2)
There is however one major problem, similar results were obtained in Kuopio, another province in Finland, where no special measure were introduced. This has been noted and explained by two academics from Trinity College, Dublin, Dr James McCormick and Dr Peter Skrabanek as early as 1988. In a letter to The Lancet they compared the results from the two provinces (Table 1)(3).
|All-cause mortality||1970/71||1976/77||% decline||1970/71||1976/77||% decline|
|Heart disease mortality|
Table 1. Comparison of death rates in North Karelia and Kuopio.
These results are very revealing because they provide no indication that people of North Karelia, which had massive efforts to alter the “risk factors”, fared no better than those of Kuopio, where there were no special efforts to make changes. In fact, if anything the results for Kuopio were marginally better than those of North Karelia. The authors commented as follows:
“Perhaps surprisingly, larger percentage reductions were observed in Kuopio—where there was no change in the average number of cigarettes smoked per day, no change in plasma cholesterol, and no change in mean blood pressure—than in North Karelia, in which it was claimed there had been a significant reduction in risk markers. Also unexplained is the observation that women in Kuopio and North Karelia had a larger relative reduction in mortality from coronary heart disease than men, although the reduction in risk markers in women was generally negligible or non-existent. At the end of 1977, North Karelians still had the highest mortality from coronary heart disease in Finland.”
Unfortunately this is just one more example of bad science, which has dogged so much of human nutrition in the past 50 years. The values placed on the risk factors are just “guessology”. There can be no excuse for ignoring the fact that the reductions in death rates in Kuopio were at least as good as in North Karelia, even though the risk factors remained the same. It is interesting to note that the effect of lowering TC is based on the results of the Lipid Research Clinics Coronary Primary Prevention Trial. This was subject to a detailed critique in a recent blog (4). It is unbelievable that a body such as WHO should place so much reliance on evidence that is so obviously flawed. The reality is that so many “scientists” who prepare these reports simply follow the official line and discount or ignore any research that does not support it.