As you"ve maybe already heard, people form Mediterranean suffer less cardiovascular problems from people in any other country in the world where the consumption of animal fat is high. Also medical studies indicate the same.
One possible reason could be that in Mediterranean olive oil consumption is pretty high.
 
About olive oil
Olive oil is a rich source of monounsaturated fat which is protective against heart disease because it displaces saturated fat from the diet. It is a source of antioxidants including vitamin E, it is the healthiest type of oil with 0% cholesterol and it is also rich in vitamins against aging. Olive oil dissolves useful substances coming from food that cannot be absorbed by the human body, lowers cholesterol levels in the blood and it is known to lower blood sugar levels and blood pressure.

 It can be used in cooking in al kind of ways: in salads, as a base for sauce or to fry vegetables and fish (frying with olive oil reduces its quality because of heat). I also heard that Romans used to drink it (but that was oil from the green olives, while slaves were alowed to drink oil from mellow (black) olives), and old people say it is useful to drink a small amount in the morning on empty stomach to improve digestion system preformance.

Extra-virgin olive oil
Firstly, let"s see the difference between the extra-virgin and virgin olive oil.
Extra-virgin olive oil is alowed to be called so if the olives are brought to production 24-72 hours after harvesting and if its acidity is less than 1%.
But usually olives rarely get to the oil factory in that time so that"s how we get a virgin olive oil with acidity usually less than 2-3%. Both of those types are very good and very healthy.
One anoter thing about it is that oil bought in stores is rarely as dense as it is the one that can be bought from the people who are producing it for themselves (if you wan"t to taste the perfection, visit the Mediterranean and buy some from the local people).
In stores can be found a few other types of olive oil, but those are usually partly (with heat and/or chemically) refined ones so it is best to search for virgin types.

Mediterranean diet or?
In my opinion Mediterranean diet should be called a Mediterranean cousine as it is not really a diet. It is only way of living. In the ancient times people didn"t have the possibility to buy all kinds of processed foods in the stores. They could only rely on what the earth gave them, so it is naturally that they were eating a lot of fruits and vegetables like figs, grapes, almonds or wild potatoes. It is possible that they have been eating fish more than twice a week, but today is recommended once or twice a week. Meat is consumed in moderation, mostly poultry.
Wine should be consumed in moderation too usually with a meal. That means not more than two glasses for men and one glas for women a day.

Times changed
We live in a different world now when people have more money and more choices. I"m looking to my grandmother who is not so thin anymore mostly because of the fact that she likes to eat a lot of cakes. So choice is yours, get back to the basics, choose health!

The Art of Creating Good Health