Olive oil has been a basic ingredient of the Mediterranean diet for centuries B.C. for some of the world’s healthiest populations. It is produced by pressing olives and extracting the oil through physical (mechanical) means, although some lower quality versions can be extracted by using chemicals. The process includes the grinding of the olives either using large millstones or steel drums, the malaxation, where the microscopic oil drops become amassed and the separation from water and fruit pulp either through pressing or through centrifugation. What is left is called pomace. The classification, following the IOC (International Olive Council) standards is as follows:
- Extra Virgin Olive Oil with less than 0.8% free acidity.
- Virgin Olive Oil with free acidity up to 1.5%
- Refined olive oil that is obtained by refining virgin olive oil with high acidity or defects that are eliminated after the process
- Olive pomace oil
Extra virgin olive oil is considered to be the best quality of all with the lowest acidity, a superior distinctive taste and no defined sensory defects. For most olive oil producing countries it accounts for less than 10% of their production while for our country, Greece, the percentage reaches an 80%.
Nutrient content of 100gr of olive oil:
- Saturated fat: 13.8%
- Monounsaturated fat: 73% (oleic acid)
- Omega 6: 9.7%
- Omega 3: 0.76%
- Vitamin E: 72% of the RDA
- Vitamin K: 75% of the RDA
The composition of the olive oil’s constituents varies by cultivar, region, altitude, time of harvest and extraction process. The nutritional value of the extra virgin olive oil lies on its content in unsaturated fat – oleic acid -, in lipo–soluble vitamins – vitamin E – and in polyphenols, including oleocanthal and oleuropein that act both as antioxidants and anti-inflammatory nutrients in the body and explain the unique benefits of this culinary oil.
Research has shown that the oleic acid can reduce inflammatory markers like CRP (C – reactive protein) while the strong concentration of polyphenols lowers activity in the arachidonic acid pathway that mobilizes the inflammatory process. Furthermore, oleocanthal acts like ibuprofen, a very popular anti-inflammatory drug.
The anti-oxidant and anti-inflammatory nutrients of the extra virgin olive oil lower the risk of oxidative stress (damage or risk of damage from the process of overly reactive oxygen-containing molecules) and chronic inflammation (caused by unbalanced metabolism, exposure to environmental contaminants etc) key drivers of heart diseases. The hydroxytyrosol, HT, a key polyphenol, protects the blood vessels from being damaged by overly reactive oxygen molecules. Olive oil also provides protection to the LDL molecules from oxidative damage, improves endothelial function, prevents from unwanted blood clotting and lowers blood pressure.
Many types of cancer are contributed to oxidative stress and chronic inflammation. The polyphenols as well as the oleic acid are resistant to oxidation, have the special ability to protect DNA from oxygen damage and fight cancer at the molecular level. Researchers have also found lower rates of upper digestive track cancers in populations that regularly consume olive oil.
The polyphenols of the extra virgin olive oil (oleuropein, tyrosol, hydroxytyrosol, ligstroside etc) help balancing the bacteria in the digestive track and slow down the growth of unwanted bacteria including Helicobacter pylori bacterium. Olive oil intake also improves bone health for post-menopausal women as well as the cognitive function among older adults, especially their visual memory and verbal fluency.
One or two tablespoons of extra virgin olive oil per day maintain our body’s health and offer us the energy we need for our everyday activities.