There is a long history of the connection between olive products and good health. Mediterranean regions of the world report the cultivation of olives dating back 6,000 years. In more recent times, olive products have formed an important part of many cuisines across the world – e.g. Extra Virgin Olive Oil (EVOO) is the primary fat included in the Mediterranean diet. It is well known that EVOO has well established health benefits, with a large body of scientific evidence supporting this. However, the olive tree, also known as Olea europaea, also provides a range of products with a variety of health benefits.

This article looks to explore the main products of the olive tree and provides a summary of the evidence related to the health benefits of these products.

 

 

Extra Virgin Olive Oil

 

Olive oil is the broad term used to describe the natural juice of the olive fruit, which since ancient times, has been a major dietary oil and fat around the world.

When referring to ‘olive oil’ it is important to appreciate the various grades that exist. In short, the main grades of olive oil are:

  • Natural Olive Oils
    • Extra Virgin Olive Oil is the highest grade of olive oil – it is simply the fresh juice of the olive.
    • Virgin Olive Oil is also the natural olive juice, but it is a lower quality oil. (Note: in Australia, Virgin Olive Oil is not available for purchase).

 

  • Refined Olive Oils
    • Refined Olive Oil is produced from refining natural olive oils (of a lower quality) using methods such as deodorisation.
    • Olive Oil is a blend of Refined Olive Oil and some natural olive oil.

It is not appropriate to interchange the terms ‘Olive Oil’ and ‘Extra Virgin Olive Oil’ – as described above, these are not equivalent products.

The health benefits associated with Extra Virgin Olive Oil are related to the healthy mono-unsaturated fat profile, along with the minor components such as biophenols (antioxidants), phytosterols, vitamin E and squalene. Olive oil/Refined olive oils have been processed, and due to this, they contain no/only trace levels of these minor components.

A full list of bioactive compounds found in EVOO is here.

There are a wide range of well-evidenced health benefits related to Extra Virgin Olive Oil:

  • Prevention of Overall Mortality
  • Prevention of CVD, Coronary Heart Disease, and Myocardial Infarction
  • Prevention of Diabetes or improved Glycaemic Control in existing Type 2 Diabetes Mellitus
  • Reduction in Overall Cancer Incidence
  • Prevention of Neurodegenerative Diseases
  • Prevention of Mood Disorders
  • Reversal of Fatty Liver Disease
  • Prevention of Overweight and Obesity.

The health benefits of Extra Virgin Olive Oil are summarised here.

 

 

Olive Leaf Products

Unlike products from the olive fruit, olive leaf products are less well known. However, there is an emerging body of evidence to demonstrate the health benefits of the olive leaf. The olive leaf contains an array of phytochemicals – olive leaf extract and olive leaf tea have been used as ancient remedies for thousands of years.

Of all the olive leaf products, the most well researched is olive leaf extract.

 

Olive Leaf Extract

Olive leaf extract is a supplement that is derived from the olive leaf, which contains bioactive compounds that provide a health and wellness tonic that has many researched health benefits. The extract contains a wide variety of compounds which work synergistically to deliver a multitude of therapeutic actions.1,2

  • Antioxidant activity – Olive leaf extract is a potent antioxidant that has been shown to have one of the highest free radical-scavenging activities (of 55 medicinal herbs tested, including green tea and milk thistle).3
  • Antimicrobial and antiviral activity – Over the past 10 years, in vitro research has demonstrated that olive leaf extract is effective against a wide range of pathogens.4–13 Specifically, oleuropein has been shown to have in vitro antibacterial activity against some gram-positive and gram-negative human pathogenic bacterial strains.7 Despite the antimicrobial effect of specific biophenols found in olive leaf extract, research shows that the antimicrobial activities of the combined phenolics has a similar or better effect than any one individual biophenol.14 To date, there are no human clinical trials which evaluate the effect of olive leaf extract against pathogens for common infections.
  • Insulin sensitivity – A randomised, double-blinded, placebo-controlled, crossover trial in New Zealand (published in 2013) assessed the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein and 9.7 mg hydroxytyrosol) on insulin action and cardiovascular risk factors in overweight middle-aged men at risk of metabolic syndrome.15 Twelve weeks of supplementation with olive leaf poylphenols significantly improved insulin sensitivity and  pancreatic ß-cell secretory capacity.15
  • Heart health – Published research demonstrates the effects of olive leaf extract for heart health:
    • A 2008 paper assessed the effects of olive leaf extract to reduce blood pressure in borderline hypertensive monozygotic twins. Results confirmed the anti-hypertensive and lipid-lowering effects of olive  leaf extract.16
    • A 2014 double-blind, placebo controlled cross-over human dietary intervention trial evaluated the effects of regularly consuming a combination of olive leaf, green coffee bean and beetroot extracts on blood pressure, arterial compliance, blood lipids, blood glucose and insulin sensitivity.17 Results showed that there was no significant effect  on any outcome measures tested.
    • A randomised controlled trial published in 2017 demonstrated that phenolic-rich olive leaf extract had hypotensive and lipid-lowering  18
    • Olive leaf extract has also been shown to improve vascular function in human research.19

For more details on the olive leaf – download this booklet – ‘The Olive Leaf – An Ancient Health Remedy’.

 

Olive-Based Supplements

There are various olive-based supplement products available around the world. The two main supplements that are derived from olives are Hydroxytyrosol and Squalene supplements.

 

Hydroxytyrosol

Hydroxytyrosol has a potent antioxidant activity – it has one of the highest know ORAC (oxygen radical absorbance capacity) results known for a natural antioxidant. (ORAC is a method used to determine the antioxidant capacity of a food or chemical substance).20

There is also evidence related to the health benefits of hydroxytyrosol in the following areas:

  • Anticancer activity
  • Anti-inflammatory activity
  • Antimicrobial activity
  • Antithrombotic activity
  • Antiatherogenic capacity and cardioprotective effect
  • Retino-protective activity

For more information about hydroxytrosol read this article.

Squalene

Squalene supplements are a potent natural antioxidant.

Squalene is a natural antioxidant compound that is found in varying amounts in both animal and plant sources.21 It is classified as a triterpene hydrocarbon (highly unsaturated), and is a natural lipid that is a major intermediate in the biosynthesis of cholesterol in the liver. 22,23

In nature, the highest levels of squalene can be found among olives, sharks, liver oil, wheat germ and rice bran.23 The main animal source of squalene is sourced from certain deep-sea shark varieties. For consumers seeking products containing a plant-based squalene source, olive tree offers a viable alternative.

Squalene is found in high amounts in Virgin Olive Oils – ranging from 0.8 to 13 g/kg, depending on the olive cultivar, oil extraction technology and the level of refining.23

 

Olive-Based Cosmetic Products

The below information summarises the benefits of olive-based products for skin / cosmetic use:21,25–31

 

Extra Virgin Olive Oil – Benefits

When applied topically, there is evidence to support the following effects of EVOO on the skin:

  • Free radical species can cause significant damage to skin cells. The antioxidants in EVOO can work to reduce such damage.
  • EVOO contains many antioxidants, such as vitamin E (tocopherols), which can help to repair damaged skin and retain skin radiance.
  • Hydroxytyrosol (naturally found in EVOO) can help to prevent free radical damage to the skin.
  • The vitamin E content of EVOO has an anti-ageing effect, as it helps restore skin smoothness and protect from ultra-violet light.
  • EVOO helps regenerate skin cells and soften dry skin.

 

Refined Olive Oil – Benefits 

When applied topically:

  • Olive Oil is well known as a natural moisturizer for the skin. In ancient Greece, it is reported that Olive Oil was used as a beauty product as well as being a major component of the Mediterranean Diet.
  • Olive Oil helps regenerate skin cells and soften dry skin.

 

Olive Leaf Extract – Benefits 

When applied topically:

  • Potential reduction of skin erythema (redness).
  • Potential improvement in skin blood flow and dehydration.

 

Olive Oil Extract – Benefits 

When applied topically:

  • A very effective emollient which is quickly and efficiently absorbed deep into the skin, restoring healthy flexibility (without leaving an oily residue).
  • Assists with occlusion allowing for improved skin hydration.
  • Has potent antioxidant properties that may reduce oxidative damage caused by sunlight exposure.
  • Has an oxygenating effect in cells which can help reduce the signs of ageing.

 

For more information about olive-based products and health, subscribe to the Olive Wellness Institute monthly newsletter.

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