The Mediterranean Diet Story
The story of the California Mediterranean Diet is in many ways a story of the history of nutrition through the 20th century. For the first half of the 20th century, nutrition research focused on discovering the nutritional causes of deficiency diseases. During this period the majority of vitamins were isolated. Food fortification to prevent deficiency diseases was one of the primary nutrition interventions. As the century progressed other nutritional issues began to move to the foreground.
One of the most important nutritional researchers of the 20th century was a physiologist named Ancel Keys. You may have heard of the K-rations used to feed the soldiers during World War 2? Ancel Keys developed the K-ration. In the 1950’s Ancel Keys became concerned about what is now the primary nutritional problem in the world, which is nutrition as a cause of chronic disease. He specifically was interested in determining the nutritional causes of heart disease. He wondered why some countries have high rates, and some have low rates, and he designed a study to look at lifestyle factors and diet in relation to risk of heart disease. This was called the Seven Countries Survey and it looked at the diets and death rates in regions of the US, Greece, Japan, Finland, Yugoslavia, Netherlands and Italy. It is from the results of this study that the relationship between cholesterol and heart disease began to be developed.
The Seven Countries Survey showed that the lowest mortality rate of all the groups studied was on the Greek island of Crete. It has been said that a man living on Crete in the 1950’s, and eating the traditional diet at that time, had the longest life expectancy of any man in the world. Long life spans have also been seen in those eating a similar diet in southern Italy, Spain and France, and that eating pattern has become known as The Mediterranean Diet.
The Mediterranean Diet is a diet that is based primarily on plant-based foods that are minimally processed. The majority of the diet is made up of fruits and vegetables, whole grains, legumes (dried beans), nuts, and unprocessed olive oil. Fish is eaten at least several times a week. Wine is consumed in moderate amounts. There is some variability in the use of dairy and chicken in the different Mediterranean diet patterns but red meats, processed foods and sweets are very limited.
The Harvard School of Public Health and Oldways Preservation and Exchange Trust published a Mediterranean Diet Pyramid which reviews the principles. You can find it at this link:
Follow-up diet intervention studies have shown that implementing a similar type of eating pattern today can reduce heart disease and high blood pressure. Two of the most famous studies are the Lyon Diet Heart Study, which followed the plant based principles of the Mediterranean Diet and included fish and wine, but did use a canola oil margarine in place of only olive oil as the fat (Those French needed something to replace their butter!) This study showed a dramatic decrease in follow-up cardiac events in those who already had heart disease. The DASH diet for managing hypertension had a similar structure, with a heavy emphasis on fruits, vegetables, whole grains, legumes and nuts, but the diet also included low-fat dairy products in fairly liberal amounts (up to 3 servings per day). Blood pressure was significantly reduced on this diet. Other population studies have shown a Mediterranean eating pattern may reduce the risk of cancer and some other chronic diseases.
Research on foods has now progressed to looking at a variety of plant-based compounds present in fruits, vegetables, whole grains, nuts, legumes and olive oil. These compounds are called phytochemicals and research has focused on the ability of various phytochemicals to protect the body against disease. Thus you may hear of the benefits of eating blueberries, or pomegranates, or walnuts, or drinking red wine. But when many of these phytochemicals are provided together as part of a mixed diet, such as occurs with the traditional Mediterranean Diet, the protection is much more powerful than any one phytochemical alone.
Another area of research has been on the good “omega-3” fats. The Mediterranean Diet was not particularly low in fat, but contained a high amount of both plant omega-3 fat (from walnuts and a wild plant called purslane) and fish omega-3 fat. Omega-3 fats can have powerful effects on fighting inflammation, reducing clotting and even stabilizing heart rhythm so these are a very important factor in the reduction of heart disease seen with the Mediterranean Diet. Finally the diet contains a high amount of fiber and we now know that fiber can help control both blood sugar and cholesterol levels. So in the study of the Mediterranean Diet we see the progression of nutrition research over the past century, from looking at individual nutrients to prevent deficiency in the beginning , to looking at whole eating patterns to prevent chronic disease in the end.
The California Mediterranean Diet is based on the concepts of the traditional Mediterranean Diet, but with the addition of foods proven in some of the newer studies to be associated with similar positive outcomes. Non-fat and low-fat dairy products are a good source of protein and calcium, and based upon the results of the DASH study it seems reasonable to include these foods in moderate amounts if desired. A margarine free of trans fats and high in monounsaturated fats and containing plant omega-3 such as an organic canola oil margarine, is a reasonable option for an alternative fat to olive oil or butter at times, as shown in the outcomes of the Lyon Diet Heart Study. Most importantly, the use of a variety of plant foods grown in California, including healthy foods and seasonings from traditional Latin and Asian cuisines, makes the California Mediterranean Diet a healthful diet with the variety to please modern tastes and lifestyles.
© 2015. Dayna Green-Burgeson RD, CDE. All Rights Reserved.