Olive oil may protect against bowel cancer, according to Spanish researchers. Dr R. Bartoli (department of gastroenterology, University hospital, Barcelona) and colleagues found that a diet containing olive oil, as opposed to safflower oil, prevented colonic carcinogenesis in rats (Gut 2000;46:191).
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Olive oil may protect against cancer through effects on prostaglandins, researchers say |
After 19 weeks of administration of the carcinogen azoxymethane, tumours developed in 58 per cent of the olive oil group, 45 per cent of the fish oil group and 83 per cent of the safflower oil group. The number of malignant colonic tumours per rat was 0.8 for the olive oil group, 0.7 for the fish oil group and 2.5 for the safflower group. The preventative effect of n3 fatty acids on colon carcinogenesis has already been reported, the researchers say.
The authors comment that because oleic acid is found in other fat sources that act as tumour promoters, it is likely that it is other components of the olive oil, such as squalene, flavonoid and polyphenolic compounds, that have chemopreventive activity against colon carcinogenesis.
They suggest that both olive oil and fish oil may prevent carcinogenesis through effects on arachidonate metabolism. The oils may inhibit the formation of prostaglandins that stimulate colon cancer proliferation, they say.