A recent study has once again confirmed that people who closely follow ‘the Mediterranean Diet’ live longer than other Europeans (1). So what exactly is the Mediterranean diet and how does it exert this spectacular effect.

The Mediterranean diet is not a specific diet plan or diet program but a collection of eating habits that are traditionally followed by the people of the Mediterranean region. There are at least 16 countries bordering the Mediterranean Sea and food habits vary between these countries according to culture, ethnic background and religion. But there are a number of characteristics common to them all…(2).

• A high consumption of fruits, vegetables, potatoes, beans, nuts, seeds, bread and other cereals
• Olive oil used for cooking and dressings
• Moderate amounts of fish but little meat
• Low to moderate amounts of full fat cheese and yogurt
• Moderate consumption of wine, usually with meals
• Reliance on local, seasonal, fresh produce
• An active lifestyle

Protection from chronic diseases

In a recent study (1) the diets of more than 22,000 people living in Greece were ranked according to how closely they adhered to the traditional Greek style Mediterranean diet. During the 4 years of the study, it was found that the closer people followed the traditional diet the less likely they were to die from either heart disease or cancer, with slightly greater protection against heart disease than cancer. Overall, people following the Mediterranean diet most closely were 25% less likely to die during the study period than those who did not, suggesting that those closely following the Mediterranean diet end up dying later than those who do not.

The secret ingredients

Since mortality statistics first identified that Mediterranean populations were living longer than other Europeans, scientists have been trying to deduce which components of the Mediterranean diet are responsible for its considerable benefits. Here are some of the candidates so far...

Olive oil

Olive oil is first choice for investigation as it is used almost exclusively in Mediterranean cooking instead of butter, margarine and other fats. Olive oil is a rich source of monounsaturated fat, which is protective against heart disease, possibly because it displaces saturated fat from the diet. Olive oil is also a source of antioxidants including vitamin E. But it is important to remember that olive oil is used to prepare vegetable dishes, tomato sauces, salads and to fry fish.

Fruit and vegetables

A high intake of fresh fruit and vegetables has been shown to be protective against both heart disease and cancer; probably because of the antioxidants they contain (3). Tomatoes have come under particular scrutiny because they feature so heavily in Mediterranean food. Tomatoes are indeed a major source of antioxidants and heat processing such as cooking, as in the preparation of tomato sauces is recommended as it increases the availability of lycopene, one of the main antioxidants in tomatoes.

Oily fish

It has also been suggested that fish, in particular oily fish such as sardines, have important health benefits (4). Oily fish are a source of omega-3 polyunsaturated fats and the complex long chain derivatives of these fats appear to be particularly beneficial to heart health because of their anti-inflammatory and vasodilatory properties, which keeps blood flowing smoothly.

Wine in moderation

Throughout the Mediterranean wine is drunk in moderation and usually taken with meals. For men moderation is two glasses per day, for women one glass per day.
Wine, especially red wine, contains a vast array of plant compounds with health-promoting qualities called phytonutrients. Among them, polyphenols, which are powerful antioxidants, protect against LDL oxidation and other pathologic sequelae of the oxidative process. Other phytonutrients play a role in the inhibition of platelet aggregation, vasodilation,etc.

Combined effect

In the Greek study (1) individual components or food groups of the Mediterranean diet did not provide any significant protection. In practice it is likely that a combination of all the different ingredients of the diet make it so healthy. Not only that but other factors such as a more relaxed attitude to eating, plenty of sunshine and more physical activity are likely to be contributing to the overall healthy lifestyle in this region.

Times are changing

But times are changing and nowadays fewer people have the lifestyle to follow the traditional diet. Professor Lluis Serra, President of The Foundation for the Advancement of the Mediterranean Diet (5) believes this is both an opportunity and a threat. ‘Sociological changes mean that people are less likely to spend time in the kitchen preparing food, but at the same time it is a great opportunity for catering outlets and restaurants, especially as Mediterranean people now know that their traditional fare is very healthy’ he said.

References

1. Trichopoulou A, Costacou T, Bamia C, Trichopoulos D. (2003) Adherence to a Mediterranean diet and survival in a Greek population. New England Journal of Medicine 348:2599-2608
2. Willett WC, Sacks F, Trichopoulou A, Drescher G, Ferro-Luzzi A, Helsing E, Trichopoulos D. (1995) Mediterranean diet pyramid: a cultural model for healthy eating.
   Am J Clin Nutr. 1995 Jun;61(6 Suppl):1402S-1406S. Review.
3. WHO/FAO (2003) Diet nutrition and the prevention of chronic diseases. Geneva, Switzerland. Available at www.who.int
4. Hu FB, Willett WC. (2002) Optimal diets for prevention of coronary heart disease.
   JAMA. 2002 Nov 27;288(20):2569-78. Review.
5. www.dietamediterrranea.com

FOOD TODAY 05/2004