The Framingham Study is a famous long-term health survey. According to an NIH webpage, its goal was “to identify the common factors or characteristics that contribute to CVD by following its development over a long period of time in a large group of participants who had not yet developed overt symptoms of CVD or suffered a heart attack or stroke.”
That is not quite right. It was originally called the Framingham Diet Study. Now it is called the Framingham Heart Study. Why the change? Well, Michael Eades, the author of Protein Power, found an early report on the findings of this study and wrote a fascinating post about it. One of his excerpts from the report:
In undertaking the diet study at Framingham the primary interest was, of course, in the relation of diet to the development of coronary heart disease (CHD). It was felt, however, that any such relationship would be an indirect one, diet influencing serum cholesterol level and serum cholesterol level influencing the risk of CHD. However, no relationship could be discerned within the study cohort between food intake and serum cholesterol level.
In the period between the taking of the diet interviews and the end of the 16-year follow-up, 47 cases of de novo CHD developed in the Diet Study group. The means for all the diet variables measured were practically the same for these cases as for the original cohort at risk. There is, in short, no suggestion of any relation between diet and the subsequent development of CHD in the study group.
That is, the findings of the study completely contradicted what the researchers believed (as indicated in the name Framingham Diet Study). This is what Leonard Syme taught his introductory epidemiology students on topic after topic: Well-known conclusions are far less certain than you think.
Thanks to Tom.
“Burr & Butland (1988) found vegetarians to suffer significantly lower mortality from heart disease than health conscious non-vegetarians. Mortality from ischaemic heart disease was 57% lower in vegetarians than the general population, and 18% lower than in non-vegetarians following a healthy lifestyle. Deaths due to cerebrovascular disease was 43% lower in the vegetarians compared with the general population.
A study of nearly 28,000 Seventh Day Adventists in California noted a clear trend of increasing incidence of heart disease with rising frequency of meat consumption (Snowdon, 1988). […]
The protective effect of a vegetarian diet is believed to be related to the lower blood cholesterol levels seen in vegetarians. Repeated studies have demonstrated the low blood cholesterol levels of vegetarians (Resnicow, 1991).” https://www.vegsoc.org/info/health2.html
Obviously, diet has nothing to do with either cholesterol levels or heart disease.
As John Tierney points out in his review of “Good Calories, Bad Calories: Challenging the Conventional Wisdom on Diet, Weight Control, and Disease,” by Gary Taubes, “To bolster his [low fat] theory, Dr. Keys in 1953 compared diets and heart disease rates in the United States, Japan and four other countries. Sure enough, more fat correlated with more disease. But critics at the time noted that if Dr. Keys had analyzed all 22 countries for which data were available, he would not have found a correlation.”
https://www.nytimes.com/2007/10/09/science/09tier.html
When it comes to longevity, the one variable that empirically makes the biggest difference in all animal studies is caloric intake: the lower (to a point), the better. So when people talk about low-fat, high-fiber “Third World” and vegetarian diets, the critical intervening variable may well be low caloric intake. Epidemiological studies involving countries like Japan and Korea should factor in the twenty-year span during the middle of the 20th century when caloric consumption fell drastically.
At any rate, the incidence of heart disease or cancer in any population is meaningless unless paired with actual life expectancy. In Japan, death from stroke over the past 50 years has fallen dramatically. Death from heart disease has climbed. Each generation of children has been bigger than their parents. Longevity has steadily increased, despite the fact that Japanese men still smoke like crazy. Studies have pointed to a strong inverse relationship between consumption of animal fat and stroke.
https://www.bmj.com/cgi/content/full/333/7559/148-b
Everybody dies of something. What matters is when, and the quality of life up to that point.
Cool stuff, digged