Providers newsletter

Nutrition: The Scientific Foundations of the Mediterranean Diet


By Holadoctor

The Mediterranean diet has been the subject of countless nutritional studies. Its focus on fresh produce, fruits, legumes, whole grains, nuts, lean proteins, and healthy fats has made it a leader not only in delicious food, but also in disease prevention. 

In addition, it is one of the few diets supported by a solid body of scientific studies, both small and large, that have demonstrated its advantages in helping to lower blood pressure and cholesterol, reduce the risk of type 2 diabetes, and improve overall cardiovascular health.

One of these mega-studies is the Seven Countries Study (SCS), one of the first collective international studies. The SCS was begun in the mid-20th century to examine nutritional culture, saturated fat consumption, and cardiovascular disease (CVD) in seven countries: the United States, the Netherlands, the former Yugoslavia, Finland, Greece, Italy, and Japan.

The research was conducted simultaneously with dozens of studies, which were followed up on 25 and 50 years after they began.

Part of this research focused on the Mediterranean diet and applied the Mediterranean Adequacy Index (MAI), developed to assess how close a diet is to the Healthy Reference National Mediterranean Diet (HRNMD), in which Mediterranean dietary patterns are inversely correlated with the prevalence of risk factors for chronic disease.

The Seven Countries Study showed that animal food groups, with the exception of fish, were strongly positively related to coronary heart disease mortality and that plant foods, with the exception of potatoes, were inversely related. 

Of the individual foods, butter, hard margarines, and meat were most strongly associated with coronary heart disease mortality rates. The factor score, i.e., the degree of the risk factor, was positive for foods of animal origin and negative for plant foods. Population factor scores were positively correlated with coronary heart disease mortality rates.

In their search for longevity, the scientists found that people living in southern Europe not only lived longer than those from many other parts of the world, but they also had much lower rates of cardiovascular diseases.

In plasma metabolomic studies, the Mediterranean diet was able to attenuate the negative cardiovascular effects of branched-chain amino acids, ceramides, and certain metabolites. Other studies indicate that the amounts of polyphenols generally present in this diet are sufficient to trigger substantial changes in the metabolic pathways that play a key role in cardiovascular health.

Diet has traditionally been considered a major determinant of cardiovascular health. In fact, one of the seven metrics of cardiovascular health proposed by the American Heart Association (Life’s Simple 7) directly addresses eating a healthy diet. But additionally, four of the six other proposed health metrics (body mass index, blood pressure, total cholesterol, and blood sugar) are closely determined by dietary habits. 

In Latin America and the Caribbean, cardiovascular diseases are responsible for nearly one-third of all annual deaths, 1.8 million deaths. Most CVD is caused by risk factors that can be controlled, treated, or modified. According to experts, implementing nutrition programs that include more ingredients from the Mediterranean diet would help dramatically reduce risk factors and improve the cardiovascular health of the region’s population.

The 10 Basic Principles of the Mediterranean Diet

  1. Use olive oil as your main source of added fats.
  2. Eat lots of fruits and vegetables, legumes, and nuts. 
  3. Bread and other grain products should be part of your everyday diet. 
  4. Foods that have undergone minimal processing or are fresh and locally produced are best.
  5. Daily consumption of dairy products, mainly yogurt and cheese.
  6. Red meat should be consumed in moderation, if possible as part of stews and other recipes. 
  7. Eat plenty of fish and eat eggs in moderation.
  8. Fresh fruit should be your everyday dessert. Dairy desserts, sweets, and cakes only occasionally. 
  9. Water is the beverage par excellence in the Mediterranean diet. 
  10. Staying physically active every day is just as important as eating well.

NOTE: This story was produced using content from the original study or report and from other medical research, as well as health and public health sources, highlighted in related links throughout the article.