Let's look at the historical research behind dietary recommendations in the US. Dr. Ancel Keys, a famous researcher in the 50s through the 90s, traveled the world discovering diets and their effects on health. In his travels, Dr. Keys noticed there were varying rates of heart disease depending on the countries he visited, and was intrigued by the relationship between what people ate and their overall health. Dr. Keys began an epidemiological study to research this link. The Seven Countries Study was formally started in 1958. In total, 12,763 males between 40 and 59 years of age were enrolled as 16 cohorts in 7 countries in 4 regions of the world, the United States, Northern Europe, Southern Europe, and Japan.
The Seven Countries Study still continues today. One of the first observations of this study was that, there was very little heart disease in Crete and a very high prevalence of heart disease in the US and East Finland.
When Dr. Keys compared the amount of fat people in these countries ate, he plotted a graph showing that the less fat people ate, the less heart disease they contracted. Japan is at the bottom, with the lowest fat and lowest prevalence of heart disease. The US had the highest fat consumption and the highest prevalence of death from heart disease.
This study was the first of its kind and led to a lot of press. Fat became a villain. Dr. Keys shared his research findings globally in talks to scientists and politicians. At the time, politicians were very concerned with the state of health in the American public. In the 1970s, Senator McGovern released the McGovern Report, which led to the first food guide pyramid. The guide recommended sparing use of fat and an increase in the consumption of grains in the form of cereal, bread, and pasta to 7 to 11 servings per day. These guidelines were later adopted by the World Health Organization.
The public trusted and followed these government recommendations. Immediately following the first US food pyramid, people started eating less fat and more carbohydrates in the form of cereals. Sugar consumption from sugar cane also increased. To prove this correlation between fat intake and heart disease in mortality, Dr. Keys designed a double-blind 4.5 year randomized trial, the Minnesota Coronary Experiment. It was conducted in six Minnesota state mental hospitals and one nursing home and involved 4,393 institutionalized men, and 4,664 institutionalized women. Randomized patients ate a diet low in saturated fat, where the saturated fat was replaced with nonsaturated fat in the form of Alpha Linoleic acid, the other group ate a diet high in saturated fat. The foods were designed to look exactly the same, so none of the nurses or doctors knew who is eating what. The Minnesota Coronary Experiment looked at arteriosus chlorotic heart disease, a hardening of the arteries in the heart In vascular lesions or strokes in the central nervous system, death from cardiac arrest, effects of hypertension on the heart and kidneys, clots in the heart, and many other things. There was no difference in the rate of disease for those people who had the dietary intervention, and this was even more obvious in women. In fact, in some cases, people on the diet did even worse in terms of disease.
Around the same time, another study was taking place with about 458 men with coronary heart disease, participated in a trial of secondary prevention for two to seven years. They were allocated randomly to two dietary groups. In one group, the diet consumed derived 9.8% of calories from saturated fat and 15% from polyunsaturates. In the second group, saturated fat contributed 13.5% and polyunsaturated fatty acids 8.9% of total calories. Overall, the five-year survival rate was 81%. The majority of the men had already made changes in their diets, smoking habits, and had lost weight. But surprisingly, overall survival was slightly better in the second group, the group the consume greater amounts of saturated fat.
Interestingly, the epidemiologist and the statistician who participated in the Seven Country Study did another analysis and looked at 22 countries. Japan had the lowest fat and the lowest mortality. France was in the eighth place, with high fat and low mortality. The Netherlands in 15, Norway in 17, Denmark in 6, and Sweden in 19. They all had what you would consider a high-fat diet with low mortality. So what is happening there?