Spanish researchers were curious to know why people who consume a diet rich in olive oil have less cancer.
Researchers from the University Autònoma de Barcelona discovered the oil is particularly effective against breast cancer.
In fact, a dribble a day is enough for it to be effective. Olive oil attacks tumours on several fronts by stunting growth, forcing them to implode. In addition, it protects against potentially-cancerous damage to DNA.
After experiments on rats, researchers found the oil thwarts a gene that promotes breast tumour growth.
Another Spanish study found that olive oil "puts down" a gene associated with hardening of the arteries and heart disease.
Dr. Gerald Weissmann is editor-in-chief of the FASEB journal (Federation of American Societies for Experimental Biologies) which published the finding.
He commented: "This study is ground-breaking because it shows that olive oil and a Mediterranean diet affect our bodies in a far more significant way than previously believed."