The last decade or two has olive oil has received considerable attention from the nutritional community on account of its heart-healthy properties. The benefits this oil has for us have generally been ascribed to its high content of monounsaturated fat, which studies suggest effects changes in blood fat levels that reduce the risk of cardiovascular complications such as heart attack and stroke. However, another boost was given to olive’s oil image recently when a study published in the Annals of Oncology showed that its most plentiful monounsaturated fat – oleic acid – has the ability to mute the effect of a common breast cancer gene. The promise here is that olive oil, in addition to being good for the heart and circulation, is a bosom buddy too.
While this recent research linking olive oil’s chief constituent with protection from breast cancer is promising, it is actually only part of a body of evidence which suggests this foodstuff may help ward off the big C. Specifically, laboratory studies have identified that olive oil contains a range of compounds known as polyphenols that have what is known as ‘antioxidant’ activity. Through their ability to quench potentially damaging molecules known as ‘free radicals’ in the body, antioxidants are thought to offer some protection against chronic diseases such as cancer.
While the recent Annals of Oncology study does help our understanding of the beneficial effects the constituents of olive oil may have in the body, it is not the first piece of research to link olive oil consumption with a reduced risk of breast cancer. The results of several studies appear to show that relatively high consumers of olive oil have about a 25 per cent reduction in risk of breast cancer compared to low consumers. Other research has linked higher olive oil consumption with a reduced risk of cancers of ovary and womb too. The cancer-quelling properties of olive oil seem to extend to men too; with studies linking its consumption to some protection from cancers of the colon, pancreas and lung. All this research has led some scientists to suggest that a decent intake of olive oil may help to explain the relatively low incidence of certain cancers in the Mediterranean region.
Those looking to get good doses of polyphenols from their olive oil are best advised to opt for extra virgin varieties as lab analysis reveals that it is these oils (from the first pressing of olives) that offer the highest polyphenol content. It will perhaps come as no surprise that it is not just olive oil, but the fruit from which it is derived, that offers a rich stash of these health-enhancing nutrients. However, it appears that olives differ in more than appearance and flavour; tests show that black olives generally contain higher levels of polyphenols compared to green varieties. The preferred chemical constitution of black olives is reflected in enhanced antioxidant activity too. The evidence suggests that olives and olive oil have the potential to protect against both heart disease and cancer. Including these foodstuffs in the diet is likely to bear considerable fruit from a health perspective.