What is it about diets that

Vol. 4 No. 3 Summer 2009 The Mediterranean Diet W hat is it about diets that fascinate us? For most, diets bring the promise of achieving a desira...
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Vol. 4 No. 3

Summer 2009

The Mediterranean Diet

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hat is it about diets that fascinate us? For most, diets bring the promise of achieving a desirable state of health and well-being. Because this can mean different things to different people, there are an enormous number of diets accessible to consumers. There are diets for athletes, liquid diets, diets to suit cultural or social imperatives and diets for specific allergic or medical conditions. Common diet names include the Atkins, Feingold, Pritikin or Scarsdale diets; there are also the Shangri-La, Natural Foods, Luteinfree, Cabbage Soup and Grapefruit diets, as well as the Rastafarian, Kosher or Buddhist diets. Despite the vast array of diets available, there is little doubt that the majority of dieters seek a diet in order to lose weight and maintain their new weight status permanently. Implicit in the understanding of most mainstream diets is the notion that the dieter will feel and be healthier (although for some dramatic weight loss diets, this may not be the case). The one diet that has stood out above all the rest and has largely bypassed most nutritional controversies is the Mediterranean Diet. It is a bit of a misnomer because the Mediterranean Sea contains several very large islands and is bordered by more than 20 different countries, each with its own distinct cuisine. In fact, even

Morton Satin ∙ Salt Institute within the borders of a single Mediterranean country, such as Italy, you can find very different diets for those people living along the coastal regions, such as the Neapolitans and those living in, let’s say, Avellino, less than 25 miles away, nestled in the heart of the Abruzzi Mountains. Neapolitans will eat far more fish and seafood, while residents of the Abruzzi will consume considerably more meat, chicken and legumes. If the diets of the Neapolitans were compared to their countrymen living in Bologna, you would think they lived on different continents. How then, can the diet in Italy be compared with those of Morocco, Egypt, Spain, or Turkey? In fact, there is no single Mediterranean diet as such. Our understanding of the Mediterranean diet is really a synthesized pastiche of several foods that are commonly consumed in the countries surrounded or bordered by the Mediterranean Sea. More than any other food, the olive represents the Mediterranean. The olives of biblical reference - the olive branch representing peace and olive oil used to anoint those who aspired to greater holiness. Olive oil is one of the most delectable eating oils, conferring wonderful taste and mouthfeel to all foods on which it is used. Olive oil is also one of the most nutritious oils, as it contains a very high level of

monounsaturated fats, most notably oleic acid and epidemiological studies suggests that a higher proportion of monounsaturated fats in the diet is linked to a reduction in coronary heart disease risk1. There is also considerable clinical data to show that antioxidants in olive oil can provide additional heart health benefits such as positive cholesterol regulation and LDL cholesterol reduction, and that it exerts additional anti-inflammatory and anti-hypertensive effects in humans2. Of course, there are many other foods common to the region - dates, pomegranates, honey and various legumes that have been considered healthful from time immemorial. Historically, the Mediterranean has always been depicted as a region of bountiful fruits, vegetables, cereals and legumes - and, if high density protein was sought, then the sea yielded up its bountiful harvest of fish. Fruits, vegetables, cereals, legumes and fish are the foods typical of the Mediterranean coastline. In most of the region’s countries, the inland production of sheep, goats, and cattle (where good pastures exist), together with the dairy products produced from them, have entered the diets, mostly as cheeses and in the eastern Mediterranean, as yogurt.

The Mediterranean Diet Each country has its own particular combination of foods leading to distinct diets. These diets carried on from antiquity until well into the time of the Roman Empire. Slight changes occurred during the period of Empire to reflect the broad trade of foodstuffs that accompanied it. But the basic focus on cereals, vegetables, fruits, fish and legumes continued until the influence of the invading barbarians from the North (forest dwelling meat eaters) began to be more established.

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Here is an example of Castelvetro’s thoughts: Of all the salads we eat in spring, the mixed salad is the best and most wonderful of all. Take young leaves of mint, those of garden cress, basil, lemon balm, the tips of salad burnet, tarragon, the flowers and tenderest leaves of borage, the flowers of... cress, the young shoots of fennel, leaves of rocket, of sorrel, Rosemary flowers, some sweet violets, and the tenderest leaves or the hearts of lettuce. When these precious herbs have been picked clean and washed in several waters, and dried.... with a clean cloth, they are dressed as usual, with oil, salt and vinegar. However, England had far more ambitious things to think of, such as building an empire and extracting the wealth of its distant colonies to supplement its own limited resources. England continued with its humdrum diet of meat and starchy vegetables punctured occasionally by sweets made from the sugar obtained from its distant tropical possessions.

The promotion of the benefits of the Mediterranean-type diet took place in England during the early Renaissance, when the Italian, Giacomo Castelvetro, living in England wrote his book, “A Brief Account of the Fruits, Herbs and Vegetables of Italy.”3 He tried, without success, to convince the English to eat more fruits and vegetables. It is interesting that recent epidemiological studies seem to support the notion that “The Sacred Law of Salads” (i.e., raw salads and generous amounts of olive oil) - originally proposed in Castelvetro’s book is considered the first example of customized diets for cancer prevention based on individual genetic make-up.4

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Although concern with the impact of food upon health continued, it began to be driven by the new science of nutrition – the study of specific nutrients found in various foods and agricultural products. Much of the incentive behind this science came out of the necessity of keeping sailors and soldiers alive and in good health during the extended sea voyages necessary to expand and maintain the growing empire. As a result, the focus fell upon individual foods and their nutrients rather than diets. Of particular interest were the foods that demonstrated anti-scorbutic properties to prevent scurvy and those foods, such as “portable soup”, that would keep up a man’s strength at the cheapest cost.

The focus on individual nutrients continued well into the 20th century as the science of nutrition developed. There were some notable exceptions where whole diets were prescribed to improve health such as the diet regimes that J. H. Kellogg instituted at the Battle Creek Sanitarium. But, by and large, the focus remained on specific nutrients. This began to change somewhat in the 1950s when the nutritionist Ancel Keys (known for his development of K-rations during World War II) noticed that the cardiovascular performance of Southern Italians and residents of the island of Crete were so much better than their counterparts in the North of Europe. He attributed this to their high consumption of olive oil, salads, vegetables, fruits and cereals. The fact that, unlike their counterparts in Northern Europe and USA, these coastal Mediterranean residents lived in regions that had virtually no large industry and held to a slower-paced rural lifestyle that included 3-4 hour lunch-siestas, went almost totally unrecognized. At the time, Keys was promoting the critical role of cholesterol in the etiology of cardiovascular disease. The nutrient profile of the generic Mediterranean diet fit his advocacy perfectly and he immediately began promoting its benefits. Unfortunately, he ignored whatever did not fit his purposes, namely lifestyle and one particular nutrient - salt. Olive oil is the anchor of the Mediterranean diet. When drizzled on salads and vegetables or white cheeses such as mozzarella and ricotta or grilled

SALT & Health / Summer 2009

The Mediterranean Diet fish, it adds flavor and a pleasing mouthfeel. But olive oil by itself is rather bland and thus is always accompanied by salt. Even the descriptions of Castelvetro back in the 17th century highlight salt, though it was a very costly commodity at the time. People’s preference for salt may vary, but salt has always accompanied the consumption of olive oil – salt is olive oil’s alter ego. Salt is a critical element of the diet of Southern Italians, Cretians and all other residents of the Mediterranean region. Salt is found everywhere olives cannot be consumed unless they’re soaked in heavy salt brine for weeks. The white Greek feta cheese is cured and stored in salt brine. Anchovies, capers, olives, cod and fish roe are all Mediterranean staples and are all packed in salt. The breads, pastries and sauces of the Mediterranean are all high in salt. Virgin olive oil, so cherished for making salads, is slightly bitter because of all the unique antioxidants it contains, so salt is especially important for improving its taste. The famous Greek taramosalata, is made from salted codfish roe; tzatziki is made from salted, fresh cucumbers that are drained and added to yogurt; North African baba ghanoush is made of roasted and mashed aubergine, blended with tahini, garlic, lemon juice and lots of salt before being topped with olive oil and so forth. Yet, the people who consume all these highly salted foods of the Mediterranean are the very ones that Keys described as having amongst the best cardiovascular performance in the world - but he made no mention of salt. The Mediterranean diet banner was picked up and promoted by Professor Willett and colleagues at Harvard University as a food pyramid – an idea that was readily captured by the media. The name

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“Mediterranean Diet” took root and became entrenched in our everyday food jargon without specific reference to any one Mediterranean country. In other words the Mediterranean diet was a fabrication to fit current notions of what the diet should be - tied loosely to the southern coastal Mediterranean eating patterns and claiming the best cardiovascular performance. Again, what appeared to be left out was the fact that high levels of salt were commonly consumed in the Mediterranean diet. What was great about the newly promoted Mediterranean diet was that it could be so tasty. It was full of great salads, delicious fruits and vegetables, mouth-watering pasta and grilled fish – how could anyone go wrong with that? What was just as important was that it encouraged people to take the time to eat and savor their foods, not simply to scarf down as many calories as possible in the space of five minutes. The diet, enhanced by mental images of the beauty of the Mediterranean coastline and the lithe, bronzed bodies of Mediterraneans began to take hold. The number of restaurants serving Mediterranean fare exploded.

Not wanting to be left behind, the National Heart, Lung and Blood Institute (NHLBI) chose to cash in on the Mediterranean diet. They decided to support a study to test the effects of the Mediterranean diet on hypertension7. Two issues were immediately clear; 1) the NHLBI wanted to see if they could establish a relationship between diet and blood pressure, based upon what was already common knowledge (i.e. the Mediterranean diet resulted in good cardiovascular performance and; 2) that there was little doubt as to the eventual outcome of the trial - a fact revealed by the very name of the study - DASH - Dietary Approaches to Stop Hypertension. In fact, only one approach was taken

Blood pressure (BP) is recorded as two numbers—the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats). The measurement is written with the systolic on top and the diastolic on bottom. For example, a blood pressure measurement of 120/80 mm Hg (millimeters of mercury) is expressed as “120 over 80.”

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The Mediterranean Diet - the Mediterranean diet. No other unique diets were tested. Researchers cobbled together a simple version of the Mediterranean diet (the main difference being less olive oil, as it was not as popular then) and called it the DASH diet. (Because of the difference in olive oil content, the Mediterranean diet is generally considered superior to the classic DASH diet�.) Researchers then compared the DASH diet to a “typical” American diet. A diet regime halfway between the American and Mediterranean diet, termed the “Fruit and Vegetable” diet was also used to show a gradation of response. In order to amplify the resultant outcome, the patient population (cohort) was heavily weighted in favor of those people that were prone to hypertension (i.e. 60% were Afro-Americans). The sodium levels were kept constant in all three diets at 3,000 mg/day to approximate what was considered to be the normal per capita amount consumed in the USA. The study showed that the DASH diet worked - no surprises there - it was just a matter of determining how effective it was. The results of the DASH diet were very impressive, confirming that the Mediterranean diet was healthy and resulted in reduced blood pressure. The DASH diet reduced systolic BP by 5.5 mm Hg more and diastolic BP by 3.0 mm Hg more than the American diet did. Reductions with the Fruits and Vegetable diet were 2.8 mm Hg and 1.1 mm Hg – about half of that obtained with the DASH diet. What was very impressive was the 11.4 mm Hg drop in systolic BP that occurred in hypertensive patients when they compared the DASH diet to the American diet.

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DASH trial results Category

DASH – American (mm Hg)

DASH – F & V (mm Hg)

F & V – American (mm Hg)

Systolic BP All Non-hypertensive Hypertensive

-5.5 -3.5 -11.4

-2.7 -2.7 -4.1

-2.8 -0.8 -7.2

Diastolic BP All Non-hypertensive Hypertensive

-3.0 -2.1 -5.5

-1.9 -1.8 -2.6

-1.1 -0.3 -2.8

most Americans. There was no doubt that the Mediterranean/DASH diet could be useful in an American context, but it might not produce quite the same cardiovascular results simply because the lifestyles were so different from those people in the Mediterranean coastal areas. With such an impressive difference in blood pressure between the Mediterranean/DASH diet and the typical American diet, it was a bit of a surprise when the NHLBI decided to do another study to add the dimension of sodium to the diet. The new trial was called the DASHSodium trial, and again, to ensure as great a blood pressure response as possible, a cohort was selected that was heavily weighted with hypertension prone people (approx. 60% Afro-Americans).

When the results of the DASH Sodium trial are examined, it is immediately apparent that merely changing to a DASH diet (red line) has a significantly greater impact on blood pressure than simply lowering salt consumption, once more confirming the benefits of a Mediterranean-type diet. Dropping from the normal level of sodium consumption to the Dietary Guidelines recommended level reduced the systolic pressure in the American diet (blue line) by an average of 2.1 mm Hg. However, simply changing from an American diet to the DASH diet, without any changes to sodium consumption, reduced the systolic blood pressure by 5.9 mm Hg, almost three times the drop resulting from the recommended sodium reduction.

The study confirmed that the diet of Mediterranean residents was healthier (in terms of BP) than their northern neighbors and better than

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The Mediterranean Diet This may partially explain why Mediterranean people enjoy an excellent cardiovascular status despite their high salt consumption. The one third drop in sodium consumption is extremely difficult to achieve and despite major efforts in the UK, Canada and the USA over a number of years, it has not been accomplished - despite the absurd claims by some advocacy groups that salt is toxic. The DASH-Sodium trial results showed that a decent diet alone was almost three times better in reducing blood pressure than a near-impossible to achieve reduction in salt. Even the 1/3 reduction in salt consumption to the American-type diet - an impossible figure to attain - only did as well in blood pressure reduction as the DASH diet by itself (compare the final blue point to the first red point). There could be no doubt that the popular uptake of the Mediterranean diet could provide a significant health benefit to American consumers. The results further showed that if the DASH diet were to be combined with a reduction in salt consumption, there would be an additional BP drop of 1.3 mm Hg, and a 2/3 drop would add another 1.7 mm Hg drop. The problem with these two last results was that they contradicted the nature and historical experience of the Mediterranean diet. Diets with a high olive oil and vegetable content require salt to make them palatable. Cutting the salt levels by one third would make the diet far less desirable for most people and cutting out 2/3 of the salt would make the diets completely unacceptable. The net result of this was that fewer people would consume the DASH or Mediterranean diets and lose all the benefits that came from them. (It should be remembered that the Mediterranean diet contributes to far more health benefits than blood pressure reduction alone.)

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A cross-population study on this subject has not yet been done, but there is little doubt that by significantly reducing the acceptability and uptake of the DASH/Mediterranean diet, the average population blood pressure curve would be shifted to a higher level. Unfortunately, rather than using the study results to show the benefits of a better Mediterraneantype diet, the authors of the study focused almost exclusively on the marginal benefits that the salt reduction added. While the rest of the medical and nutrition field agrees that the burden of disease across the world is due to the limited consumption of vegetables and fruits9, there are still many who remain mired in the salt-blood pressure argument, oblivious to the fact that the cardiovascular performance of high salt-consuming Mediterraneans10 remains amongst the best in the world. More recently, the Mediterranean diet had been demonstrated to be useful in reducing a broad range of cardiovascular disease conditions and risk factors (obesity, type 2 diabetes, hyperlipidemia, and hypertension)11 as well as losses in cognitive functions and Alzheimer’s diseaese 12. For millennia, this delicious diet has well-served the people of the Mediterranean region and now it is poised to contribute to the health and well-being of all those who partake of it. There are literally dozens of books on the nutritional aspects of the Mediterranean diet and dozens more with a range of excellent recipes that are easy to make. So let’s start eating right, or as they say in Italy, “Buon appetito!”

North African Salad • 3 tablespoons extra-virgin olive oil, plus 1/4 cup • 2-3 cloves garlic, crushed and minced • 1 pound box Israeli couscous (or any tiny pasta such as ziti) • 3 cups chicken stock • 2 lemons, juiced • 1 lemon, zested • 1/2 teaspoon salt • 1/2 teaspoon fresh ground black pepper • 1 cup chopped fresh basil leaves • 1/2 cup chopped fresh mint leaves • 1/3 cup finely chopped Italian parsley • 1/3 cup dried chopped dates • 1/4 cup slivered almonds or pistachios, toasted In a medium saucepan, warm 3 tablespoons of the olive oil over medium heat. Add the garlic and sauté for 1 minute. Add the couscous and toast until lightly browned, stirring often, about 5 minutes. Carefully add the stock, and the juice of 1 lemon and bring to a boil. Reduce heat and simmer, covered, until the couscous is tender, but still firm or al denté to the bite, stirring occasionally, about 7 to 9 minutes. Drain the couscous. In a large bowl, toss the cooked couscous with the remaining olive oil, remaining lemon juice, zest, salt, and pepper and let cool. Once the couscous is room temperature, add the fresh herbs, dried dates, and almonds/pistachios. Toss well and serve. Greek Salad • 1 head green leaf lettuce, torn into bite-size pieces • 2 large ripe tomatoes, cut into strips • 1/2 cucumber, peeled, diced • 1 cup black olives • 1/2 red onion, thinly sliced • 4 small pickled hot peppers • 1/3 cup feta cheese, crumbled • 1/2 cup extra virgin olive oil • 1/4 cup red wine vinegar • 1/4 teaspoon dried oregano • Salt and freshly ground black pepper to taste Combine lettuce, tomatoes, cucumber, olives, onion, peppers and cheese in large bowl. Whisk olive oil, vinegar and oregano in small bowl until well blended. Season with salt and pepper. Pour dressing over salad and toss well to coat evenly.

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The Mediterranean Diet

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References (Endnotes)

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Keys, A., Menotti, A., Karvonen, M.J., et al. (December 1986). «The diet and 15-year death rate in the seven countries study,» Am. J. Epidemiol. 124 (6): 903–15. 2 Covas, M.I., (March 2007). “Olive oil and the cardiovascular system”. Pharmacol. Res. 55 (3): 175–86. 3 Castelvetro. G., The Fruits, Herbs and Vegetables of Italy, London, Viking, 1989, translated from the original published in 1614. 4 Colomer, R., Lupu, R., Papadimitropoulou, A., et al., « Giacomo Castelvetro’s salads. Anti-HER2 oncogene nutraceuticals since the 17th century?” Clinical and Translational Oncology, 10(1), 30-34, (2008). 5 Willett, W.C., Sacks, F., Trichopoulou, A., Drescher, G., Ferro-Luzzi, A., Helsing, E., and D. Trichopoulos, “Mediterranean diet pyramid: a cultural model for healthy eating,” American Journal of Clinical Nutrition, 61(supplement), 1402S-1406S, (199). 6 Burros, M., (29 March 1995). “Eating Well”.New York Times, accessed on August 12, 2009 at http://query.nytimes.com/gst/fullpage.html?res=990CEFD81438F93AA15750C0A963958260&sec=&spon=&pagewanted=all 7 Appel, L.J., Moore, T.J., Obarzanek, E., et al., “A Clinical Trial of the Effects of Dietary Patterns on Blood Pressure,” NEJM, 336 (16), 1117-1124, (1997). 8 Psaltopoulou, T., Naska, A., Orfanos, P., Trichopoulos, D., Mountokalakis, T., and Trichopoulou, A., “Olive oil, the Mediterranean diet, and arterial blood pressure: the Greek European Prospective Investigation into Cancer and Nutrition (EPIC) study,” American Journal of Clinical Nutrition, 80(4), 1012-1018, (2004). 9 Pomerleau et al, “Burden of Disease Attributable to Nutrition in Europe,” Public Health Nutrition, 2002; 6(5):453– 461. 10 C. Leclercq and A. Ferro-Luzzi, “Total and domestic consumption of salt and their determinants in three regions of Italy,” European Journal of Clinical Nutrition, Mar, 45(3), 151-9, (1991). 11 Martinez-Gonzalez, M.A., Bes-Rastrollo, M., Serra-Majem, L., Lairon, D., Estruch, R., and Trichopoulou, A., “Mediterranean food pattern and the primary prevention of chronic disease: recent developments,” Nutrition Reviews, 67(Supp 1):S111–S116 S111, (2009). 12 Scarmeas, N., Luchsinger, J.A., Schupf, N., Brickman, A.M., Cosentino, S., Tang, M.X., Stern, Y., “Physical Activity, Diet, and Risk of Alzheimer Disease,” JAMA, 302(6), 627-637. (2009).

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SALT & Health / Summer 2009