Part 2: Why is Olive Oil Good For Us?, by Dr Stavia Blunt

The healthiness of the traditional Greek diet is partly due to the large consumption of high quality extra virgin olive oil. Extra virgin olive oil has beneficial effects on virtually every part of the body, thanks to its unique composition.

Olive Oil consists of 98-99% fat in the form of fatty acids, and a 1-2% non-fat ('water') component which contains plant chemicals or 'phytonutrients' - the most important of which are polyphenols. The health benefits of olive oil result from those two main elements plus a third factor - the way olive oil is used in the diet.

The healthiest way to use olive oil is as part of a mixed Cretan style diet, where various synergistic effects take place. 

But how much olive oil is good for you? In Greece, as much as 30 litres per person per year are consumed - mainly as part of a mixed vegetable-rich diet. But a cup of olive oil (often with a thimble of Raki!) is frequently taken as a nutritious breakfast before going out to the fields, particularly in the winter.  And recent studies have confirmed that, even on its own, olive oil is beneficial for health, particularly when used to replace saturated or processed fats. Thus: 

1-2 tablespoons of extra virgin olive oil per day helps prevent:

* inflammatory conditions
* cardiovascular disease and stroke
* blood pressure
* peptic ulceration resulting from overgrowth of helicobacter pylori bacteria
* various cancers including stomach, small intestine, pancreas, prostate, skin, breast and other gynaecological cancers 
* osteoporosis especially in post-menopausal women
* cognitive function (Alzheimer's disease) - particularly with 'intensive use' of olive oil (i.e. not just in cooking but also in sauces and dressings)
* other neurodegenerative disease such as Parkinson's disease

Olive oil and olive leaf polyphenols also have:
* antibacterial, antifungal, antiviral and anti-malarial activity; olive leaf extract may have anti-HIV activity.

Polyphenols may also help prevent and heal sunburn

Regular intake of extra virgin olive oil also helps

  • weight loss
  • the health of the liver, kidney and pancreas
  • lower cholesterol and the ratio of bad (LDL):good (HDL) fats'
  • remove bad fats from blood vessels walls
  •  reduce oxidative stress and inflammation & has anti-ageing effects on skin
  • ​The USA rates these effects of olive oil so highly that producers are allowed to make the following claim on their labels:

    "...eating 2 tbsp (23g) of olive oil daily may reduce the risk of coronary heart disease due to the monounstaurated fat in olive oil. To achieve this possible benefit, olive oil is to replace a similar amount of saturated fat and not increase the total number of calories eaten in a day'" (US FDA).

 

Let's take a look at the fat and water components of olive oil to find out why they are healthy

 

OLIVE OIL'S HEALTHY FAT COMPOSITION

  • Almost all of olive oil's fat content is ‘good' fat. Around 75% is a mono-unsaturated omega 9 fatty acid called OLEIC ACID; around 10-15% is poly-unsaturated (linoleic and alpha Linolenic – omega 3 fatty acids); and only 9-15% is ‘bad' fat – saturated fat (palmitic and stearic acids).

 

  • Olive oil's fat content is very unusual for a culinary oil. Its ratio of mono-unsaturated fat (mainly oleic acid) to polyunsaturated and saturated fatty acids is much higher than any other cooking oil. For example, olive oil has 75% monounstaurated fat compared with only 20% for sunflower oil, and 10% for Safflower oil.

 

  • This high oleic acid content explains many of olive oil's beneficial effects, helping to lower cholesterol levels; improve circulation; reduce risk of heart disease; lower blood pressure, blood sugar, and reduce risk of certain cancers.

 

  • The acidity of the oil is a measure of the (unwanted) breakdown of fats into fatty acids (AND not A MEASURE OF THE pH) – so the lower the acidity, the better the olive oil is for health

OLIVE OIL’S HEALTHY ‘WATER’ FRACTION -  THE 1-2% NON-FATTY PART

The water content of olive oil is what makes it different from most other cooking oils – because olive oil is a fruit oil, it contains a juice which is rich in plant nutrients and vitamins. One of these is a group of natural plant nutrients called polyphenols - a new health buzz word - and extra virgin olive oil is literally packed with them.

Natural polyphenols are a group of plant nutrients which are part of the plant's own protection system against bacteria, fungi and viruses. They also serve as a natural preservative of oil once it is bottled. The polyphenols are stable throughout the range of normal domestic cooking, and help to protect the oil's alpha tocopherol (vitamin E) - so cooked olive oil does not lose any of its goodness.

The polyphenols have important benefits for humans too: first, they contribute to the flavour of olive oil - giving it pungency, pepperiness and bitterness (especially oleuropin); and they have important health benefits thanks to their potent anti-oxidant, anti-inflammatory and anti-microbial activity - as explained below.

OLIVE OIL POLYPHENOLS! 
* Olive oil contains more than 30 different polyphenols
* Polyphenols give good olive oil its bitter, peppery taste ( Oleuropin gives oil its pungency) 
* Polyphenols are very potent natural antioxidants and so protect the body from harmful effects of ‘free radicals’ which are relevant to many diseases
* Polyphenols are olive oil's own natural preservatives and an oil containing naturally high levels will have a very long shelf life 
* Polyphenols account for many of olive oil's health effects

A bitter, pungent and peppery oil is high in polyphenols and therefore high in antioxidants - and therefore very good for you!

Olive oil contains more than 30 different polyphenols, but the most important are  Oleuropin, Hydroxytyrosol and Tyrosol - and account for olive oil's bitter taste. Oleuropein is present in all parts of the olive tree (and explains its incredible resistance to disease), with especially high concentrations in the leaves.

The health effect of polyphenols in olive oil is such that the EU regulations now allow the following health claim to be placed on labels which contain a minimum level of these 3 polyphenols:

"Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress with a daily intake of 20g olive oil or more" 
(EU) Regulation No 432/2012 of 16 May 2012

 

OLIVE OIL'S VITAMINS

Some of the health benefits of olive oil are due to its vitamins and other antioxidants - vitamin E, carotein, chlorophyll and zinc.  These fat soluble vitamins are not broken down by cooking. Olive oil Squalene also contributes to the low incidence of cancer seen in Mediterranean countries.

Vitamin E: Olives have 1.6mg, or 2.3 IU per tablespoon. One tablespoon provides 8% of RDA for vitamin E.

Vitamin K: The richest sources of vitamin K are green, leafy vegetables. The greener the vegetable, the higher the content, because the vitamin is associated with the chlorophyll. According to the USDA, olive oil is the second best source.

 

 

Features which correlate with the healthiness of an olive oil:

• Low acidity (ideally <0.4%)

• Type of olive – Very High Polyphenol Content are found in: Koroneiki, Coratina, Conicabra, Moraiolo, Picual; (Low content in Arbequina, Picudo, Taggiasca).

• A good blend of green (less ripe) and black (ripe) olives in the mix

• Olive Leaves: Some producers do not remove all the olive leaves from the pressing mix, which makes it very high in antioxidants, but can make the olive oil rather bitter

• Taste: an olive oil which is bitter and peppery has plenty of antioxidants!

• Freshness – ideally you want an olive oil that is from the latest harvest

Organic olive oil is probably healthier