Including olive oil in your diet may help reduce your risk of developing colon cancer, Spanish researchers suggest. Their study results showed that rats fed an olive oil-supplemented diet had a lower risk of colon cancer than those fed diets supplemented with safflower oil. In fact, the rats that received olive oil had colon cancer rates almost as low as those fed fish oil, which several studies have already linked to a reduction in colon cancer risk.
Adding olive oil to the diet has other advantages as well. There has been interest in the health benefits of olive oil for some time, but not usually with a focus on colon cancer. The cardiovascular benefits of diets higher in olive oil are well established in improving the ratio of good-to-bad cholesterol. In addition, olive oil does not promote the secretion of bile acids as many other fats do.
Animal studies have shown that a diet high in some kinds of fat (such as corn or safflower oil) increases the risk of colon cancer, which depends on both the amount of fat consumed and the type of fatty acid it contains. Additional studies have indicated that dietary fish oil inhibits or prevents colon cancer.
Rats given a diet high in safflower oil had more premalignant changes in the linings of their colons and a higher incidence of colon cancer than those fed a diet high in fish oil or olive oil. Examination of colon tissue revealed that a diet high in fish oil or olive oil reduced the bowel tissue concentrations of arachidonate, a substance that enables the formation of cancer, to a greater extent than did a diet high in safflower oil.
The authors note that previous studies showed that fish oil can slow the division of rectal cells in humans, but the effect of olive oil on colon cells has been scarcely assessed, leading them to conclude that their findings on olive oil may be of relevance. Oleic acid is the predominant fatty acid in olive oil (about 75%), but oleic acid is also found in fats that are in foods linked to cancer in animal studies, such as beef; poultry; and corn, soybean, and sunflower seed oil.
The researchers therefore believe that other components of olive oil such as squalene and flavonoid and polyphenolic compounds may have a chemoprotective effect against colon cancer.