The attached article is the best summary I've seen on the latest research on extra-virgin olive oil and health. Particularly important are new findings that oil rich in polyphenolic compounds (anti-oxidants), that is to say extra-virgin oil:

1. Brings about dramatic decrease in oxidative stress that leads to heart disease.
2. Oleic acid fights cancer by interacting with the human genome, suggesting the development of olive-oil-based cancer therapeutics.
3. A natural anti-inflammatory substance in extra-virgin olive oil called oleocanthal could prevent/help treat arthritis.
4. Helps protect from peptic ulcers and stomach cancer by fighting eight strains of Helicobacter pylori, some of which are already immune to antibiotics.

The trick to all this is to consume between 25 and 50 grams per day (two to four table spoons)                                               Read Article