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First, some background discussion |
At a time when obesity has reached epidemic levels in much of the industrialized world, "diets" are everywhere. New diet prescriptions are constantly being developed in an effort to find solutions to this enormous personal and social health problem. Some of these diets work for some people, of course, but the successes they achieve are merely individual, and have little effect on the bigger picture - for instance, a country like the United States where fully 60 percent of the population is now considered overweight. Obesity is not the only problem. According to the World Health Organization, unhealthy diets and physical inactivity are also two of the main risk factors for high blood pressure, high blood glucose, abnormal serum lipids, cardiovascular diseases, cancer, and diabetes. Any "diet" problem lies in part in the fact that the larger cultural context of the individual - food resources and lifestyle taken altogether - do not create a climate for health. The actual Western diet or American diet of today, in this larger sense of what people generally do and eat, doesn't bear much resemblance to anything that doctors and nutrition experts would recommend - not just for proper weight, but for optimal or even adequate health. There is no single definition of a healthy diet, of course. But there are some fundamental elements that have come to be recognized and accepted by the health community. There is a remarkable consensus among the American Heart Association, the USDA, and the World Health Organization, for instance, regarding their advice on a more healthful diet and lifestyle:
Interestingly, in most respects just such a "diet" has existed and perhaps still does in the countries of the Mediterranean, including Greece, Italy, Cyprus, Spain, Portugal, northern Africa and Turkey. This is what's known as the Mediterranean diet. It's not a weight-loss diet in the prescriptive sense - like Atkins or South Beach - but a description of the food and dietary habits of the peoples of a group of countries that ring the Mediterranean Sea and share certain climate and agricultural characteristics that have shaped their diet, lifestyle, and health in distinctive ways. The Mediterranean diet (MD) began to be studied in the 1950s and 1960s, when it was reported that the population of the island of Crete seemed to live longer than average with lower incidences of heart disease, stroke and even some cancers, despite the fact that their diet was not particularly low in fat.1 Since that time, an enormous body of research has developed analyzing what the Cretans and other Mediterranean peoples were eating, and how those diets influenced their health. This research has in fact been one of the prime sources for the development of the basic dietary guidelines above. What does this cumulative body of scientific evidence suggest are the most important factors at work in the Mediterranean diet? Dr. Faustino Perez-Lopez of the University of Zaragoza and the Hospital Clínico de Zaragoza, and his colleagues recently provided a fascinating analysis of what the MD actually is...and is not...along with a comprehensive overview of the medical and health benefits which can be traced to the MD.2 |
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What is the Mediterranean Diet? |
As Dr. Perez-Lopez and his colleagues stress, what has come to be known as the Mediterranean diet is actually a group of dietary patterns that developed over centuries in more than 20 countries surrounding the Mediterranean Sea. There are many variations, and most of the research and observation that has shaped the current definition date from the way people ate and lived in the 1960s. The diets of these countries traditionally featured: generous quantities of fresh fruits, cooked vegetables, legumes, and whole grains; more moderate portions of fish, nuts, some dairy foods (particularly cheese and yogurt) and wine; and perhaps most significantly, lots of olive oil. With its reliance on olive oil for as much as 25 to 35 percent of calories in addition to nuts and oil-rich fish, this is not a low-fat diet, but it does rely on a very different kind of fat from that found in modern western diets that feature animal fats. Beyond the food they eat, the lifestyle and activity patterns of these Mediterranean populations at the time these studies occurred also need to be taken into account--as does the influence of the relatively sunny climate they still benefit from. At the time of the research studies that initially identified the MD, much of the Mediterranean region was economically depressed, and meat was relatively scarce and expensive. Many more peoples' livelihoods depended on physical labor, and obesity was not a significant issue. Many of these cultures adhered until quite recently to healthful customs like the siesta, a more leisurely out-of-doors social life, and a seasonal, natural food supply. |
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Health Benefits of the Mediterranean Diet? |
Perez-Lopez et al. have reviewed 55 years of research - more than 150 research studies - on the effects of a Mediterranean-type diet on the health and longevity of hundreds of thousands of people in countries worldwide. Most of this research has concentrated on the native populations of the Mediterranean region, in particular Greece, Italy and Spain, but other studies have looked at people as far away as Australia and the United States whose dietary habits matched the MD profile. These studies have found that various aspects of the Mediterranean diet are consistently associated with lower rates of cancer, overweight, cardiovascular risk, hypertension, metabolic syndrome, and mortality from all causes. In other words, the Mediterranean diet contributes to increased longevity. One of the largest and most significant studies - the European Prospective Investigation into Cancer and Nutrition Elderly study, or EPIC-compared diets from nine countries in terms of their relationship to the Mediterranean diet. This study has yielded a huge store of data that is still being mined. A number of analyses have supported the claim that people following some variation of the MD tend to live longer. One found that a healthy 60-year-old man who closely follows such a diet is likely to extend his lifespan by one year.3 The HALE project studied older European men and women and found that those who adhered to an MD-type diet had a 23 percent lower annual mortality rate.4 A U.S.-based 10-year study of 566,000 older men and women found that those who reported following an MD-type diet had a 20% lower risk of death from heart disease, cancer or any other cause.5 The Mediterranean diet is associated with reduced incidence of a combination of serious health risks factors - abdominal obesity; high triglycerides, fasting glucose, and blood pressure levels; and low HDL (good) cholesterol - which together are known as the metabolic syndrome.6 It is also linked to lower risk of hypertension and cardiovascular disease and higher survival rates following heart attacks. A number of studies also show that the MD may have significant cancer-preventive properties. The key factor behind many of these health benefits is the antioxidant effect strongly associated with olive oil and many of the MD fruits and vegetables - tomatoes in particular. Olive oil is also a rich source of mono-unsaturated fatty acids (MUFAs), carotens, phenolic compounds and chlorophyll that protect the heart through anti-thrombotic, anti-inflammatory and anti-hypertensive properties. The fatty omega-3 acids contained in certain fish have similar cardio-protective properties and may even protect against Alzheimer's disease. 7 |
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Prescription from the Description |
Unfortunately, recent years have seen much of the traditional Mediterranean lifestyle give way to a more "modern" and stressful set of habits in the more developed countries of the region, like Italy, Spain, and Greece. But while the MD may be in some ways a record of a former way of living, understanding the key elements and how they function, has enabled development of new prescriptive guidelines which can lead to better health and longer lives anywhere in the world. A Mediterranean-inspired diet and lifestyle can yield health benefits even in the short term, so even older people who adopt these foods and practices may gain some protection against heart disease, atherosclerosis, high blood pressure, diabetes and even Alzheimer's.8 |
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References |
1. Epidemiological studies related to coronary heart disease: characteristics of men aged 40-59 in seven countries. 2. Effects of the Mediterranean diet on longevity and age-related morbid conditions. 3. Modified Mediterranean diet and survival: EPIC-elderly prospective cohort study. 4. Mediterranean diet, lifestyle factors, and 10-year mortality in elderly European men and women: the HALE project. 5. Mediterranean dietary pattern and prediction of all-cause mortality in a US population: results from the NIH-AARP Diet and Health Study. 6. Mediterranean diet and metabolic syndrome: a cross-sectional study in the Canary Islands. 7. Mediterranean diet, Alzheimer disease, and vascular mediation. 8. Modified Mediterranean diet and survival: EPIC-elderly prospective cohort study. |
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About the author |
Matthew Papaconstantinou, Ph.D., is a research fellow in the Department of Biochemistry and Molecular Biophysics at Washington University School of Medicine in St. Louis, MO. A native of Greece, Matthew learned of the Mediterranean diet through his own experience and hopes that by sharing the scientific background he will help others understand and adopt its benefits. He is interested in research on diet and weight loss, has a website where he reviews weight loss programs and is developing a free online diet calorie counter. |
Note: The inclusion of this article by Matthew does not indicate endorsement of his website by the owners of MoreLife.org.
Additional reading suggested regarding the Mediterranean diet: "The Secret Behind the Mediterranean Diet", Life Extension Magazine January 2010 (not yet online).
