This Pyramid, which represents the optimal, traditional Mediterranean diet, is based on the dietary traditions of Crete and southern Italy in the 1960s. It is structured in the light of nutrition research carried out in 1993 and presented by Professor Walter Willet during the 1993 International Conference on the Diets of the Mediterranean, held in Cambridge, Massachusetts
The Mediterranean Diet Pyramid underlines the importance of the foods making up the principal food groups. Each of these individual food groups offers some, but not all, of the nutrients one needs. Food from one group cannot replace that of another group. All the groups are necessary for a healthy diet.
The basic products of the Mediterranean diet, in descending order of recommended quantity and frequency, are:
Grains
These form the base of the majority of meals in Mediterranean countries – bread (wholemeal or otherwise), pasta, couscous and rice.
Fruit and vegetables
Meals are more flavoursome when in-season products are selected and they are cooked very simply. In the Mediterranean countries the dessert is generally fruit.
Legumes and Nuts
A wide variety of legumes and nuts, such as chickpeas, lentils, haricot beans, pine kernels, almonds, hazelnuts, walnuts, etc. are used in cooking.
Olive Oil and Olives
“Olive oil” and “Virgin olive oil” are used throughout the Mediterranean. The former is normally used for cooking. The latter, which is appropriate for all uses, is excellent when consumed raw to best appreciate its aroma and flavour and to benefit fully from all its natural components. The proportion of fats in the traditional diet of Crete observed by Professor Ancel Keys, was more than 40% kcal/day of which 8% were saturated fats, 3% polyunsaturated and 29% monounsaturated (olive oil).
OLIVE OIL AND CANCER
Epidemiological studies suggest that olive oil exerts a protective effect against certain malignant tumours (breast, prostate, endometrium, digestive tract, …).
A number of research studies have documented that olive oil reduces the risk of breast cancer. Eating a healthy diet with olive oil as the main source of fat could considerably lower cancer incidence. The reason is that the cell mutations caused by cancer are partly due to toxins which, when consumed through the diet, attack DNA. On passing through the liver, these toxins produce free radicals that then attack DNA. To combat such free radicals, the body needs vitamins and antioxidants like those contained in olive oil.
It has also been reported that an olive-oil-rich diet is associated with reduced risk of bowel cancer. The protective effect of olive oil is irrespective of the amount of fruit and vegetables eaten in the diet.
Recent studies have demonstrated that olive oil provides protection against cancer of the colon. Lately, research has been looking into the metabolic implications of fats, more specifically the protective role of olive oil in chronic liver disease and in the disorder of the intestines known as Crohn’s disease. Results point to beneficial effects of olive oil on pre-cancerous lesions. After analysing three types of diet, research scientists arrived at various conclusions. The olive oil diet reduced the number of cancerous lesions; the number of tumours that developed was clearly and significantly low; and the tumours were less aggressive and had a better prognosis.
This beneficial effect could be related to oleic acid, the predominant monounsaturated fatty acid in olive oil. It has been observed that this fatty acid lowers the production of prostaglandins derived from arachidonic acid, which in turn plays a significant part in the production and development of tumours.
However, it is not excluded that other constituents of olive oil, such as antioxidants, flavonoids, polyphenols and squalene may also have a positive influence. Squalene is believed to have a favourable effect on the skin by reducing the incidence of melanomas.
Olive oil also adds to the taste of vegetables and pulses whose benefits in cancer prevention have been amply proved.
Some very promising, current research is centred on the protection provided by olive oil against child leukaemia and various cancers, such as oesophageal squamous cell cancer.
Much has still to be discovered about how olive oil affects cancer and concrete data are still lacking on the mechanisms behind the beneficial role it plays in the prevention or inhibitionof the growth of different types of cancer. However, according to the information available at present, olive oil could actsimultaneously during the different stages involved in the process of cancer formation.
OLIVE OIL AND OBESITY
Olive oil is a nutrient of great biological value. Like all other fats and oils it is high in calories (9 Kcal per gram), which could make one think that it would contribute to obesity. However, experience shows that there is less obesity amongst the Mediterranean peoples, who consume the most olive oil.
It has been demonstrated that an olive-oil-rich diet leads to greater and longer-lasting weight loss than a low-fat diet. It is accepted better because it tastes good and it is a stimulus to eat vegetables.
OLIVE OIL AND DIABETES
An olive-oil-rich diet is not only a good alternative in the treatment of diabetes; it may also help to prevent or delay the onset of the disease. How it does so is by preventing insulin resistance and its possible pernicious implications by raising HDL-cholesterol, lowering triglycerides, and ensuring better blood sugar level control and lower blood pressure. It has been demonstrated that a diet that is rich in olive oil, low in saturated fats, moderately rich in carbohydrates and soluble fibre from fruit, vegetables, pulses and grains is the most effective approach for diabetics. Besides lowering the “bad” low-density lipoproteins, this type of diet improves blood sugar control and enhances insulin sensitivity.
These benefits have been documented in child and adult diabetes.
OLIVE OIL AND CHOLESTEROL
Olive oil lowers the levels of total blood cholesterol, LDL-cholesterol and triglycerides. At the same time it does not alter the levels of HDL-cholesterol (and may even raise them), which plays a protective role and prevents the formation of fatty patches, thus stimulating the elimination of the low-density lipoproteins.
The beneficial effect of olive oil consumption with regard to cardiovascular disease has been demonstrated in primary prevention, where it reduces the risk of developing the disease, and in secondary prevention, where it prevents recurrence after a first coronary event.
At present, research is revealing the effectiveness of the Mediterranean diet in the prevention of secondary coronary events and the positive influence of olive oil on the depression associated with such events and on mood. These findings are very important in view of the high incidence of depression in the modern-day world and the great risk it poses in recurrent heart disease.
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