The 7-Country study: the grandeur of Cretan Diet

At the end of the 1950s the 7-Country Study, an epidemiological longitudinal study, was designed to investigate the relations between diet and cardiovascular diseases. Sixteen cohorts were selected in Finland (East,West), Italy (Montegiorgio, Crevalcore, Rome railroad), Yugoslavia (Dalmatia, Slavonia, Velika Krsna, Zrenjanin, Belgrade), Netherlands (Zutphen), USA (US railroad), Greece (Crete, Corfu) and Japan (Tanushimaru, Ushibuka).  During the 1960s, data regarding food consumption were collected from random samples of these cohorts. Interestingly, each country and even each region within the same country had different food consumption patterns. In Finland the intake of milk, potatoes, edible fats, and sugar products was very high. A similar but of lower intake pattern was recorded in The Netherlands. A high consumption of meat, vegetables and fruit was observed in the United States, Rome, Belgrade and Zrenjanin (Yugoslavia). All three Italian cohorts typically consumed very large amounts of cereals and alcohol. Alcohol intake was also high for the cohort from Dalmatia (Yugoslavia), where also fish was particularly popular. In Velika Krsna the consumption of bread and cheese was high, while for the Slavonia cohort, cereal products and egg consumption dominated the food pattern. In Crete massive quantities of olive oil and fruits were consumed while the other Greek cohort in Corfu was found to be particularly fond of bread and fruits. For the Japanese cohorts, rice, fish and soy products were the foods most extensively consumed.     

The research was conducted on a sample of 12500 individuals aged 40-59 years old. Researchers monitored the health of their subjects, focusing primarily on cardiovascular incidents (coronary diseases and strokes) and the development of cancer tumors. In terms of death rates, results were rather stunning. Crete had by far the lowest death rates among all monitored regions. Specifically, in the first 15 years of the study only 38 of the Cretan participants died of coronary heart disease and 317 of cancer. The second best performance was that of Japanese with a total of 136 deaths caused by coronary heart disease and 623 deaths due to cancer. Death rates in the rest participating regions were 202(338)^[1] in Corfu-Greece, 242(394) deaths in Yugoslavia, 462(622) in Italy, 636(781) deaths in the Netherlands, 773(384) in the US and 972(613) in Finland.   

Among several other significant findings, death rates were observed to have a positive relation with the average percentage of dietary energy from saturated fatty acids, a negative relation with dietary energy percentage from monounsaturated fatty acids, while they appeared to be unrelated to dietary energy percentage from polyunsaturated fatty acids, proteins, carbohydrates, and alcohol. All death rates were negatively related to the ratio of monounsaturated to saturated fatty acids. Oleic acid, which represents 68-82% of total extra virgin olive oil fats, accounted for almost all differences in monounsaturates among cohorts. All-cause and coronary heart disease death rates were low in cohorts with olive oil as the main fat. No causal relationships are claimed; however it is important that specific characteristics of populations as well as of individuals within populations are taken into consideration before evaluating risks.

The impressive performance of Cretans in the 7-Country Study was attributed to their lifestyle and to their dietary pattern that evidently allowed them to shield themselves against cancer and fatal cardiovascular incidents. Indeed, intense workout was a daily routine for Cretans at that time as most of them were employed in agriculture and stock raising. As for their dietary pattern, Cretans having exited a devastating Nazi occupation had certain food categories available. Specifically, olive oil, which was found in relative abundance in the large and millennia old Cretan olive grove, was in their daily menu, combined with large quantities of grains, either as bread or as rusks (famous ‘ntakos’). In addition, their diet included massive quantities of fruits and vegetables as well as a great deal of legumes consumed 3-4 times per week. Moderate quantities of fish and poultry were consumed on a weekly basis. Importantly, red meat was almost absent from Cretan diet. Facing surviving problems, locals could not afford to use the meat of their sheep and goats in order to cover their own nutrition needs. Instead, they used their milk to produce cheese products part of which they kept for themselves, while they sold the rest to make a living. Last but not least, 1-2 glasses of wine produced by them would accompany their meals.

The above is the pattern of Cretan Diet. At this point an important distinction has to be made. Cretan Diet is indeed part of Mediterranean Diet; to be more exact, Cretan Diet served as the starting point for what was later on called Mediterranean Diet. However, Mediterranean Diet does not equal Cretan Diet. The latter carries some distinctive characteristics, relating to the frequency as well as the amounts of each food type consumed, that make it a whole lot different from the traditional dietary patterns followed in other countries of the region such as Italy and Spain. Indicatively, the average daily olive oil intake in Cretan Diet is 70gr while the corresponding figure in Italian and Spanish Diet is 15-20gr^[2]. That differentiation is clearly illustrated in the results of the 7-Country Study^[3], which scientifically validate the superiority of the Cretan Diet in terms of coronary heart disease and cancer preventing properties, over the patterns followed in Italy or even the Greek island of Corfu.

Our fathers taught us the way and we look forward to sharing it with you. In the exact words that every Cretan recipe begins with:

‘First, we pour some extra virgin olive oil in the pot…’