Healthy Oleic Acid in Olive Oil and Sesame Oil

Olives & Olive Oil – Essentials of Mediterranean Diet

Olive oil is consumed in all Mediterranean diets but American researchers overlooked this critical food! Oleic acid in Olive oil slows the aging process by reducing inflammation.

Good research but bad result – Why?

A large number of people in many countries of the world have really poor health. Some of this has occurred because potentially good research results were misinterpreted!

In 1958 an American researcher called Ancel Keys commenced a huge research study called the ‘Seven Countries Study’. In this, Keys and his colleagues tried to identify the dietary nutrients that increased the risk of cardiovascular diseases. Cardiovascular diseases are the leading cause of death in most countries and a major underlying factor is inflammation. Key’s research team made one critical observation that people of the Mediterranean region had much lower rates of cardiovascular illnesses than Americans and Northern Europeans. Furthermore, many people lived beyond the age of 100.

The diet that promised to slow the aging process was named the ‘Mediterranean Diet‘. But here the good research ended. Many investigators have now shown that this early public health data was viewed through what I will call a ‘skewed lens’. Unfortunately, the researchers failed to look at all the evidence objectively.

Keys and his colleagues became obsessed with with cholesterol because their research found that in six countries, blood serum cholesterol levels correlated with the risk of heart attacks. Unfortunately, and against all scientific principles, the data from another 15 countries where this relationship was not so clear, were excluded! The researchers also failed to notice that people living in Mediterranean countries consumed rather large quantities of Olive Oil.

Is there a Mediterranean Diet? Which dietary factor do all Mediterranean Countries have in common?

In Italy, you always have a dipping saucer of Olive Oil

If you have travelled through many of the Mediterranean countries and even in the different regions of each country, you will know that the diets are quite variable. Each region has its own specialties. These are generally locally grown or readily available produce, especially the fruits, vegetables, fish, and meat. However, the one notable custom that all these regions have in common is their extensive use of Olive Oil.

Olive trees have been growing the region for thousands of years and since olive oil is very easily produced by mechanical processing of hand-picked olives, it is not surprising that the oil became a staple of the region. A Mediterranean Diet is typically rich in local, fresh produce (whatever that might be) with large lashings of Olive Oil!

Why is Olive Oil so good for you?

Good quality Extra Virgin Olive Oil (EVOO) has many health benefits. EVOO that has been produced from ripe, undamaged healthy olives has high concentrations of:

  • Oleic acid (that greatly reduces age-related inflammation)
  • Squaline (that protects the heart)
  • Phytosterols and Polyphenols (that have many beneficial effects)
  • Vitamin E and βeta carotene
  • Magnesium
  • More than 100 ‘volatile’ compounds that are lost if the oil is heated.

Despite the loss of volatile compounds with heating, oil that is heated is still beneficial (though not as beneficial) because the most important component of EVOO is the high (55 to 83) % content of Oleic Acid.

Oleic acid is the most important component of all our cellular membranes and our ability to produce it through our metabolism, is greatly decreased with age.

Once we are over age 40, our ability to convert other fatty acids to Oleic acid greatly declines, and when we are over 60, this ability undergoes a further dramatic decline[1]. This decline is associated with increasing inflammation, which can be significantly decreased by consuming Oleic Acid[2].

Long-lived populations of people throughout the world

People who live in Sardinia, Ikaria and Okinawa are reported to be amongst the longest living and healthiest people on the planet. These regions are known as Blue Zones. The longevity probably has a great deal to do with their hard-working and simple (not modern) lifestyle but their intake of fresh local foods and quality oils is almost certainly critical. The Sardinians and Ikarians live in islands in the Mediterranean and have a diet that includes Olive Oil. However, the Okinawans, who live in an archipelago about 580 kms off the coast of Japan don’t eat Olive Oil. Instead, they consume a diet rich in Sesame Oil.

Sesame Oil has a composition that is reasonably like that of Olive Oil. Sesame Oil does not have as much Oleic Acid (average about 49% versus 69%) and more Linoleic Acid (35% versus 12.5%). It has similarly low amounts of the saturated fatty acids Palmitic (8.5% versus 10.4%) and Stearic acid (6.5% versus 2.8%). My own published research has shown why these two saturated fatty acids need to be low.

Is either Canola Oil or Safflower Oil a good substitute for Olive Oil?

Canola was originally grown in Canada (hence its name) to produce feed for dairy, livestock, and poultry. The oil was derived from the somewhat toxic Rapeseed by reducing the toxic element Erucic Acid.

Canola crops were introduced into the USA in 1988. Based on the fatty acid content alone, Canola Oil seems to be a reasonable alternative to Oleic and Sesame Oils. It has an average content of 61% Oleic Acid and 21% Linoleic Acid. However Canola Oil must undergoe a great deal of processing. It is never ‘fresh’ and published research shows that although it has several of the benefits of Olive Oil, EVOO is superior.

Safflower Oil on the other hand is not at all similar. It does contain about 12% Oleic acid but is about 80% Linoleic Acid, which is probably highly undesirable!

Buying high quality Olive Oil

When I was researching this topic, I was alarmed to find that there are many fraudulent practices relating to the production and supply of the world’s Olive Oil. Fortunately, both in Australia and in the USA, there are strict guidelines controlling the industry, so our locally manufactured Olive Oil is reliable. Nevertheless, it seems that quite a large proportion of the Oil labelled as Olive Oil produced elsewhere in the world, and including some coming from Europe, is not what it purports to be.

This is not a reason to avoid consuming Olive Oil but just a reminder to check the label on the bottle very carefully

How much Olive Oil should you consume each day?

No study has been undertaken to determine this but if you go to Italy you will find a dipping bowl of Olive Oil on the table at every meal. I think a good rule is to have at least one tablespoon of room temperature EVOO every day. My own preference is to pour it over my hot or cold vegetables each night. It is good to have this with some Balsamic Vinegar although I personally prefer a brewed Soy Sauce. The important message here is to eat your Olive Oil ‘raw’ so that you can the benefits of the volatile compounds as well as the Oleic Acid.

Daily EVOO will significantly reduce inflammation throughout your body!


[1] Bolton-Smith C et al (1997) Evidence for age-related differences in the fatty acid composition of human adipose tissue, independent of diet. European Journal of Clinical Nutrition. 51: 619-624

[2] Ford JH (2019) Why We Age – Solving the Puzzle of Aging. Published by Expert Genetic Services – available from this website https://drjudyford.com

Published by Dr Judy

I am a PhD Geneticist and have spent many decades working in research related to reproduction and cancer. Both are affected by lifestyle, especially ageing and so I am passionate about teaching people how to change their lifestyles to optimise their health.

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