The True Health Initiative (THI) released a paper addressing four main criticisms of Ancel Keys’ controversial Seven Countries Study (SCS). Begun in 1958, the SCS observed participants’ diets, lifestyles, and biomarkers across time to better understand diet and lifestyle-related heart disease risks and mortality. The THI report calls SCS “groundbreaking” at the time of its inception, supplying “new information on risk of coronary heart disease and its relationship to lifestyle, environment, and diet.”
Through consulting primary sources and study investigators, the THI report refutes the common “disparagements of the methods, intentions, and conclusions” of SCS that “contest its primary finding, that saturated fat was correlated with heart disease, and call into question subsequent nutrition research.” Such criticism, says the THI report, is presently in vogue.
SCS was a prospective cohort study: a study in which researchers collect data on groups of people without the disease of interest—heart disease, in this case—and follow them for some time period to observing whether or not the individuals develop that disease.
Data collected at baseline and at the follow-ups included cholesterol, body mass index (BMI), blood pressure, and electrocardiograms (ECGs) to measure heart health. The study also collected medical and smoking history. Researchers also collected dietary intake data in two of the groups, including self-reported dietary recall data as well as more rigorous seven-day weighed food records for a subsample the cohorts.
The SCS included 16 different research groups, or cohorts, of men between the ages of 40 and 59 from seven countries. The countries include the United States, the Netherlands, former Yugoslavia (modern-day Croatia and Serbia), Italy, Greece, Finland, and Japan.
The THI report acknowledges and discusses a variety of important limitations of the SCS but refutes four main criticisms from the nutritional research community.
These include some critics’ allegations that Keys intentionally chose countries that fit his hypothesis rather than including accessible data from all countries in his analyses. The THI report, however, says countries included were ultimately “based on practicality and dietary variation.”
Other critics have asserted “that SCS neglected deleterious effects of sugar on health in favor of promoting a low-fat agenda.” The THI report confronts this claim and seeks to provide evidence to address other widely held criticisms it calls “false and anachronistic.”
The THI report says SCS not only provided new findings on coronary heart disease risk but also developed “important tools for standardizing nutrition and diet research.” The THI report furthermore emphasizes the danger “deliberately or carelessly misrepresenting historical events, distorting scientific findings, and misstating researcher intent“ poses to stalling or impeding nutritional research.