For more than 3000 years, people of the Mediterranean region of southern Europe and Asia Minor have used the oil produced by crushing the fruit of the olive tree (Olea europaea). In the past three decades, researchers have been investigating the protective effects of the Mediterranean diet, looking for a link between the dietary habits of these populations and a reduced incidence of cardiovascular disease.
It’s now thought that the high consumption of olive oil in these countries is a major contributor to the many health benefits of the Mediterranean diet.
Olive oil outside your body
Besides being used in cooking, olive oil has many other uses. It was used as a lamp oil by the ancient civilisations of the Mediterranean region, as well as in many ancient religious rituals, and was also applied to the skin as a moisturiser. It’s still used in many cosmetics and soaps, valued for its moisturising and rejuvenating properties.
What’s in an oil?
Olive oil is made up of approximately 75 per cent monounsaturated fats, the rest comprising mainly polyunsaturated fats as well as a small amount of squalene. It is the antioxidant compounds found in olive oil, known as phenols, that are responsible for giving extra virgin olive oil its fruity aroma.
It’s still unclear whether it’s the monounsaturated fats, which have been shown to have numerous cardiovascular protective properties, or the antioxidants that give olive oil its numerous health benefits. Perhaps it’s a combination of the two.
Oils ain’t just oil
A large study in 2004 looked at the dietary habits of 20,000 men and women living in Greece as they related to the incidence of high blood pressure. Eating a Mediterranean diet was found to reduce the incidence of high blood pressure. The evidence also showed the intake of olive oil was as important in the apparent reduction in the incidence of high blood pressure as the level of fruits and vegetables consumed.
A 2006 study focused on the effects of the antioxidant phenols in olive oil on heart disease risk factors. The participants were given 25ml of low-, medium- or high-phenolic content olive oil daily for three weeks. The increases in HDL or “good cholesterol” observed at the end of the study corresponded with the phenolic content of the olive oil assigned to each group. This indicates it may be the antioxidant phenols in olive oil that are responsible for its cardio-protective effects.
Mounting evidence is highlighting the role of inflammation in the development of heart disease and researchers are currently searching for new anti-inflammatory compounds. One of the phenolic compounds found in extra virgin olive oil has been shown to have anti-inflammatory effects that are strikingly similar to that of ibuprofen. This adds further evidence to the notion that eating a Mediterranean-style diet high in antioxidant compounds such as those found in olive oil reduces the incidence of cardiovascular disease.
Choose your oil
Australian olive oil consumption has risen by 300 per cent over the past decade, with current annual consumption at 30,000 tonnes. To meet the local demand as well as a burgeoning global demand for olive oil Australia’s olive oil industry has been growing very rapidly, with exports increasing tenfold in the past three years alone.
|
Type of Oil |
Extraction method |
Refined |
Exposed to heat or chemicals |
Amount of antioxidants |
Taste and smell |
Kilojoules per tbsp (20g) |
|
Extra virgin olive oil |
First pressing of the olives |
No |
No |
Highest amount |
Strong fruity aroma and taste |
740 |
|
Virgin olive oil |
Following pressings |
No |
No |
Some |
Milder taste |
740 |
|
Pure olive oil |
Blended oil |
Partially |
Possibly |
Very little |
Very mild taste |
740 |
|
Light olive oil |
Refined oil |
Yes |
Yes |
Almost none |
Almost neutral |
740 |
The quality of Australian extra virgin olive oil now rivals that produced by Spain and Italy. So, when choosing an olive oil for its health benefits, go for a locally produced extra virgin olive oil with a strong fruity taste and smell and a pale green colour.
Olive oil in your diet
Replacing the saturated fat found in foods such as butter, cheese and fried foods with monounsaturated fat found in olive oil will have many health benefits including reducing your risk of heart disease.
Extra virgin olive oil, with its high concentration of monounsaturated fats and antioxidants is superior to other cooking oils such as vegetable, sunflower and canola oils. However, as it has a medium smoking point (the temperature at which the oil will burn), it’s not advisable to use olive oil for frying at high temperatures.
Olive oil is a fat like any other oil and should therefore not be consumed in excess. However, given the health benefits of olive oil, it would be wise to make extra virgin olive oil the main fat in your diet (along with fish oil). The amount of extra virgin olive oil you should consume depends on your daily energy (calorie) intake.
However, most people will find two to three tablespoons (40-50ml) a day is an adequate amount for use in salad dressings and for cooking needs.
Oil you need to know
- Olive oil contains beneficial monounsaturated fats
- It contains antioxidants
- It increases good HDL cholesterol
- It reduces blood pressure
- It reduces inflammation
- Extra virgin is best
- Cook at medium temperatures
