A number of epidemiological studies have linked consumption of olive oil with a reduced risk of cancer and researchers are increasingly investigating this association further in laboratory studies.
But while a recent report from the US suggests that one of the oil's fats - oleic acid - could be responsible for protecting against breast cancer, the latest research, by a team at the University of Ulster in Northern Ireland, suggests that a mixture of compounds in virgin olive oil, called phenols, could protect against colon cancer.
Writing in the 20 October issue of the International Journal of Cancer (vol 117, issue 1, pp1-7), the researchers say their tests on in vitro cell models also pointed to mechanisms by which olive oil may reduce the risk of this cancer.
"We found that incubation of one cancer cell line with increasing concentrations of olive oil phenols for 24 hours protected the cells from DNA damage," said key researcher Dr Chris Gill.
"The effect of olive oil phenols on another cell line after 48 hours of exposure suggested that they may exert an anti-promoter effect in the carcinogenesis pathway," he added.
The researchers say that the olive oil phenols also led to a significant reduction in the invasiveness of a colon cancer cell line in vitro.
"The research shows that the effect is not only related to the types of fat present in the oil but also the phenolic compounds present," said Dr Gill.
"We have demonstrated that phenols extracted from virgin olive oil are capable of inhibiting several stages in colon carcinogenesis in vitro," write the researchers in the journal report.
The next stage is to assess the effects in a suitable animal model, added Dr Gill.