The Mediterranean diet: A mode... Health Article

No matter where they live on our vast and wonderful planet, people are people. But if all humans share a common biologic backbone, the peoples of the earth display a remarkable diversity of cultural norms. Language, religion, family structure, governance, music, dance, sports, and clothing are all subject to amazing cultural differences. And the human diet is every bit as diverse as the other cultural traditions.

All people eat to live, but the foods they choose depend on complex interactions between climate, geography, national resources, religion, and tradition. Each culture has its signature dishes; for example, Asians are noted for rice, noodles, and soy, Italians for pasta and bread, Germans for meat and potatoes, the French for wine and cheese, Latinos for corn, beans, and rice, and (alas!) Americans for hamburgers and fries. As migration, travel, and the global economy shrink our world, dietary diversity has diminished. But before variety becomes the exception, Americans should consider adopting the best nutritional traditions from other cultures, not just for the occasional pleasure of ethnic dining, but as a healthful pattern for everyday life. And one of the best — and most easily attained — patterns is the traditional Mediterranean diet.

When in Greece…? When doctors prescribe the Mediterranean diet, they are advising the traditional diet present in Crete and certain other rural areas in southern Greece, Italy, or France. But with globalization, the traditional dietary pattern is eroding. In the Mediterranean, as in much of the world, the Western preference for processed foods that are high in fat, salt, sugar, and calories, but low in fiber, is taking hold. Olive oil and wine are still in vogue, but exercise is not. Since the 1970s, the Greek waistline has expanded drastically; the prevalence of obesity is now as high or higher than in any area of the world except certain Pacific islands. Diabetes is also rampant, and an epidemic of heart disease may be just a heartbeat away. When in Greece, do as the Greeks used to do.

What is it?

Although the Mediterranean Basin occupies only a small fraction of the earth, there is considerable dietary diversity within the region. When nutritionists speak of the traditional Mediterranean diet, though, they refer to a centuries-old dietary pattern that has flourished in Crete, various rural regions in the rest of Greece, and parts of southern Italy and France. And that pattern has 10 characteristic features:

1. An abundance of vegetables, fruits, beans, nuts, seeds, and other plant foods.

2. An abundance of unrefined grains, such as whole-grain cereals and breads.

3. Olive oil as the major source of fat.

4. Fish in moderate to high amounts.

5. Fruit as the typical dessert, with sweets containing honey or sugar consumed several times a week.

6. Yogurt, cheese, and other dairy products consumed daily in low to moderate amounts.

7. Four or fewer eggs consumed per week.

8. Poultry consumed in moderate to large amounts and red meat in low amounts.

9. A reliance on locally grown, fresh, minimally processed foods.

10. Alcohol consumed in moderate amounts, usually as wine with meals.

Although the farmers of Crete did not analyze the nutrients in their diets, modern scientists have run the numbers. The traditional Mediterranean diet is high in complex carbohydrates and fiber but low in simple sugars, moderate in unsaturated fat, moderate in proteins, and moderate in alcohol. It's also tasty — but does it work?

Studies in Greece and Europe

The modern study of diet, heart disease, and health dates to the landmark Seven Countries Study initiated by Dr. Ancel Keys in the 1950s. It showed that regions with a low consumption of saturated fat, such as the Mediterranean countries, had a much lower incidence of coronary artery disease than regions with a high consumption of saturated fat, such as the Scandinavian countries. The study gave birth to "the cholesterol hypothesis," now accepted as fact. But current research has gone beyond fat to study many of the features of the Mediterranean diet. Here are some studies from Europe:

• A study of 22,043 adults in Greece found that people who adhered to the traditional Mediterranean diet enjoyed a lower mortality rate than those who did not. Compared to people with the least traditional diets, people with the best diets were 33% less likely to die from heart disease and 24% less likely to die from any cause during the 44 months of the study. And benefit depended on the overall Mediterranean dietary pattern rather than any individual nutrients; olive oil won't help unless you include the other good stuff in your diet.

• A study of 74,607 men and women ages 60 or older in nine European countries found that following the principles of the Mediterranean diet was associated with increased survival and longevity. Protection was consistent in Mediterranean and non-Mediterranean countries; in northern Europe, polyunsaturated fats appeared as beneficial as the monounsaturated fats favored in the olive belt.

• A study of 2,339 people between the ages of 70 and 90 in 11 European countries linked the Mediterranean diet to a 23% reduction in the overall mortality rate. And when exercise, moderate alcohol use, and avoidance of tobacco were added to the diet, the death rate was reduced by more than 50%.

• A study of 1,302 Greek patients with heart disease found that greater adherence to the traditional Mediterranean diet was associated with a 27% lower death rate during nearly four years of observation.

• A study of 1,926 Greek adults found that people who followed a Mediterranean diet enjoyed a 27% decrease in the likelihood of acute coronary artery disease; the diet was more beneficial in southern (Mediterranean) Greece than in northern Greece.

• A study of 11,323 Italian heart attack survivors found that patients who succeeded in adopting a Mediterranean diet were only half as likely to die during 6.5 years of observation as patients who did not succeed in improving their diets.

It's a small world, and Europe may seem a long way from Main Street. But although most American studies don't refer to the healthful diet as "Mediterranean," they report strikingly similar findings from a similar dietary pattern.

The Mediterranean diet for arthritis and Alzheimer's? Although the main long-term health benefit of the Mediterranean diet is protection against heart disease, it also appears to reduce the risk of certain malignancies. A small study from Sweden also raises the possibility that it may ease some signs of rheumatoid arthritis. In the study, 26 patients with the disease reported reduced arthritic symptoms after three months on the diet, while 25 control patients who remained on their normal Scandinavian diet did not improve. It's just one study, and it's brief and short-term at that. But it may provide additional motivation for some people to improve their diets as scientists continue to investigate. And if that's not enough motivation, consider an American study of 2,258 people that linked faithful adherence to a Mediterranean diet to a 40% reduction in the risk of Alzheimer's disease.

Studies in America

Harvard's Health Professionals Follow-up Study examined the effect of dietary patterns on the health of 44,875 men over an eight-year period. When the study began, all the men were 40 to 75 years of age and none had been diagnosed with cardiovascular disease or cancer. In addition to providing their medical histories and dietary information, the volunteers also disclosed details about their family medical histories, smoking, height, and weight. Then the researchers tracked the men to see if diet influenced the development of fatal and nonfatal heart disease and if that effect was independent of other heart disease risk factors.

The scientists identified two overall dietary patterns. One was a typical American diet, characterized by a high consumption of red meat, processed meat, refined grains, French fries, whole-fat dairy products, sweets, and desserts. The other pattern was a "prudent" diet, high in fruits, vegetables, legumes, whole grains, fish, and poultry. This pattern was quite similar to the Mediterranean diet, though it featured less olive oil.

The volunteers' diets were scored according to how closely they approached the American or prudent patterns. The results were striking: men with the most American patterns were 64% more likely to develop heart disease than men with the most prudent diets. And in a follow-up study, the prudent diet was also linked to a lower risk of type 2 diabetes. In both cases, these associations remained strong even after the scientists adjusted the findings for smoking, drinking, and obesity (more common in the men who followed the American pattern), as well as vitamin use and exercise (more prevalent with the prudent pattern).

Harvard University is fully coeducational, and its medical scientists study women as well as men. In reports from the Nurses' Health Study, women who followed the prudent dietary pattern enjoyed a 24% lower risk of coronary artery disease and a 26% lower risk of stroke than those who consumed Western-style foods. And when women combined regular exercise and prudent eating with other beneficial habits, they enjoyed a remarkable 83% reduction in the risk of heart disease. The Western diet was also associated with a higher risk of colon cancer.

What's good for Athens, Greece, seems to be good for Athens, Georgia.

How it works

The Mediterranean diet works because it has lots of the things that can protect you from heart disease, diabetes, and other chronic illnesses; the list includes dietary fiber, vitamin-rich fruits and vegetables, and fish, as well as the moderate amounts of alcohol that also appear to protect the heart. At the same time, it shuns items that are harmful, including saturated fat from animal sources, trans fat from partially hydrogenated vegetable oils, salty processed foods, and rapidly absorbed simple carbohydrates. The net results include lower levels of LDL ("bad") cholesterol, higher levels of HDL ("good") cholesterol, lower levels of blood sugar and insulin, and lower blood pressure readings. In addition, a randomized clinical trial of 180 patients with the metabolic syndrome, a major precursor of cardiovascular disease, found that the Mediterranean diet reduced body weight, improved arterial function, and lowered levels of C-reactive protein and other markers of vascular inflammation. Researchers have demonstrated that the Mediterranean diet produces similar risk factor improvements in healthy adults.

Statins, diet, or both? Since so many excellent medications can lower your cholesterol and reduce your risk of heart disease, why not just take a statin pill and skip the fish, whole grains, and olive oil? The answer comes from scientists in Finland who compared the effects of diet, medication, and a combination of the two. The subjects were 120 men between the ages of 35 and 64; all the volunteers had high cholesterol levels. The effects of a modified Mediterranean diet were compared with those of a normal Finnish diet, the effects of 20 mg simvastatin (Zocor) were compared with those of a placebo, and the combination of diet and medication was tested against the other groups. The modified Mediterranean diet featured monounsaturated and omega-3 fatty acids and lots of fruits, vegetables, and dietary fiber. It worked, lowering total cholesterol by 8% and LDL cholesterol by 11%. Simvastatin was even better, reducing total cholesterol by 21% and LDL cholesterol by 30%. But the combination was best of all, reducing LDL cholesterol by 41%. And the combination had other advantages. Diet alone had the unwanted effect of lowering HDL cholesterol by 5%, but the combination preserved HDL levels. Similarly, simvastatin raised insulin levels by 13%, but the combination corrected that potentially harmful result. From the standpoint of cholesterol, the Mediterranean diet can boost the benefits of medication. And diet can do things that even the statin drugs cannot. It reduces the risk of hypertension, diabetes, and obesity. It may provide some protection against Alzheimer's disease and other forms of dementia. In addition, a diet high in fiber but low in red meat may reduce the risk of colon cancer. And men may stand to gain even more than women, since the same dietary pattern that provides all these gains also appears to reduce the risk of prostate cancer. Finally, there is a third benefit of the diet that no drug can match: it tastes good.

Making it work for you

A firsthand trial of the Mediterranean diet in southern Greece would certainly be nice. Until then, you can travel the road to nutritional health right here at home. Here are some guidelines:

• Fat should supply 20% to 35% of your total daily calories. Remember that all fats are not created equal. Minimize your consumption of saturated fats; they should provide less than 7% of your daily calories. Avoid trans fats as much as possible. Favor monosaturated fats (olive oil) and polyunsaturates; omega-3 polyunsaturates from fish are particularly desirable.

• Carbohydrates should supply 45% to 65% of your daily calories. Remember that all carbs are not created equal, either. Favor complex carbohydrates rather than simple sugars, which should provide less than half of your calories from carbohydrates; the less sugar, the better.

• Protein should supply 10% to 35% of your daily calories; fish and legumes are particularly desirable sources of protein.

• Men younger than 50 should get 38 grams of dietary fiber a day; the target for older men is 30 grams a day (for women, the goals are 25 and 21 grams).

• Keep your salt intake low, aiming for less than 2,300 mg of sodium a day if you are young and healthy; below 1,500 mg a day if you are older or hypertensive.

Here's how to translate the guidelines for health into the foods you eat:

• Eat five or more servings of vegetables a day; count ½ cup of cooked or raw vegetables, 1 cup of raw leafy greens, or ½ cup of vegetable juice as one portion.

• Eat four or more servings of fruit a day; count ½ cup of fresh, frozen, or canned fruits, ¼ cup of dried fruit, one medium-sized piece of fruit, or ½ cup of fruit juice as one portion.

• Eat at least 6 ounces of grain a day. Count 1 cup of dry cereal; ½ cup of cooked cereal, rice, or pasta; or one slice of bread as the equivalent of one ounce. Whole grains should provide at least half of your grains; the more the better.

• Eat two or more servings of fish a week; count 4 ounces as one serving.

• Obtain the equivalent of 5½ ounces of protein-rich foods a day. Count 1 ounce of cooked fish, ¼ cup of cooked beans or tofu, ½ ounce of nuts or seeds, one egg, or 1 ounce of cooked lean meat or poultry equivalent to 1 ounce.

• Consume 3 cups of non- or low-fat dairy products a day.

• If you choose to drink, limit yourself to one (for women) or two (for men) drinks a day; count 5 ounces of wine, 12 ounces of beer, or 1½ ounces of liquor as one drink.

The Mediterranean diet may sound foreign, but these guidelines for nutrients are based on current American recommendations. They represent a big step forward. Still, you can do even better by giving your diet a real Mediterranean flair (see table, page 5).

Going Mediterranean in your dining room
Choose	Instead of
Grilled, baked, broiled, or steamed foods	Fried foods
Fish	Meat
Oily fish such as tuna, salmon, bluefish, and sardines	White fish
Whole-grain breads, cereal, pasta	White bread, refined grains, and cereals made with white flour
Unsalted nuts	Salted nuts
Beans, soybeans, lentils	Meat, cheese, eggs
Sweet potatoes	White potatoes
Nonfat or low-fat dairy products	Whole-fat dairy products
Olive oil (or "high oleic" sunflower or safflower oil) or canola oil	Omega-6 oils (corn, soybean, peanut, safflower, sunflower), shortening, and lard
Spreads with plant stanols and sterols (such as Benecol or Take Control)	Butter or stick margarine
Fresh, unprocessed foods	Processed foods
Fruits and vegetables	High-salt, high-sugar, or high-calorie snack foods and desserts
Lemon juice, pepper, various spices and seasonings	Salt and high-sodium condiments and sauces
Water, fruit juices, sugar-free beverages	Sugary beverages

Beyond diet

The Mediterranean diet has three major advantages: it is healthful, it is enjoyable, and it's easy to modify and adapt to American tastes and menus. But while an excellent diet is necessary for excellent health, it is not enough; it should be matched by an excellent exercise schedule. In fact, both are intrinsic parts of the traditional Mediterranean lifestyle. And just as the diet is moderate but healthful, so too is your exercise requirement. Just 30 minutes of moderate exercise (such as walking) will do the trick as long as you do it nearly every day.

The Mediterranean diet and exercise regimen are important, but they're not new. In fact, some 2,400 years ago, the Father of Medicine explained it all: "If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have found the safest way to health."

Can it be a coincidence that Hippocrates was Greek?