It is known that olive oil helps in lowering your blood cholesterol and LDL levels, thus it will raise your good cholesterol levels, HDL.
That's because olive oil contains 77 percent monounsaturated fat.
http://eatlikemira.com/2010/03/03/questions-about-fat/
http://eatlikemira.com/2010/10/27/increase-hdl-decrease-ldl/
BUT THE QUESTION! 
Do OLIVES have the same effects??
A lot of people think that unlike olive oil, olives have the ability to raise blood cholesterol.
BUT...
Olives contain some of your EFA's (Essential Fatty Acids, in this case poly-unsaturated fat) which are good for you just like olive oil...
And these are good in moderation as long as you don't over do it.
The Mediterranean diet is a beneficial kind of diet characterized by a high consumption of fruits, vegetables, whole grains, beans, nuts, seeds, healthy fats, spices and the occasional glass of wine.
It is also associated with a reduced risk of heart attacks, cancers and both Parkinson's and Alzheimer's disease. And Olives take a big part in such kind of diet! .
Along with monounsaturated fats and polyunsaturated fats, olives also contain linolenic acid, an omega-3 fatty acid and an important antioxidant that can lower triglycerides, decrease the risks of blood clots and sudden heart attacks.
But olive oil are rich in sodium and so it is not advisable for people with high blood pressure.
Note that I am talking about the non-stuffed olives. Stuffed olives can be high in fat depending on their ingredients.
10 olives contain 45 calories, are are considered as 1 exchange of fat.
