Compiled & Medically reviewed by
Dr.Sanjana.V.B. Bhms. Dbrm.Cdn

 Health benefits of olive oil

       Olive(Olea europaea) is a subtropical broad-leaved evergreen tree  that belongs to the family Oleaceae and it produces edible fruits . Olive oil is extracted from the fruit of olive plant and olive oil is a key ingredient in the diet of people of Mediterranean region.It is a major ingredient in “Mediterranean diet”.

The olive fruit is classed botanically as a drupe, similar to the peach or plum. Olives tend to have maximum oil content (about 20–30 percent of fresh weight) and greatest weight six to eight months after the blossoms appear. At that stage they are black and will continue to cling to the tree for several weeks.

History of olive oil

 The edible olive was grown on the island of Crete about 3500 BCE. It was an important crop cultivated by the Romans about 600 BCE. Later, olive plant cultivation spread to all the countries bordering the Mediterranean region. The Olive tree is also planted as an ornamental tree in suitable climates. In the early 21st century, Spain and Italy were the world leaders in commercial olive production, followed by Greece.

Olive oil extraction

    Olives are grown mainly for the production of olive oil although the fruits are edible also. Fresh, unprocessed olives are inedible as they are bitter due to a glucoside that can be neutralized by treatments with a dilute alkali such as lye. For processing as food, immature olive fruits are picked or shaken off the tree. The processed fruit can be consumed either ripe or green. Fruits for oil extraction are allowed to mature.

     Olive oil is extracted from the fleshy part of the ripened fruit of the olive tree. Olive oil varies in colour from clear yellow to golden; some varieties obtained from unripe fruit have a greenish tinge. Oils of varying characteristics and qualities are produced all over the world and the variations depend on the ripeness of the fruit.

    Pure olive oil is used largely for culinary purposes and in the preservation of foods, particularly canned fish. It is also used in the textile industry for wool combing, in the manufacture of cosmetics, in the pharmaceutical industry also.it is also used in the manufacture of high-quality castile soap, and as a lubricant.

 Globally the leading producers of olive oil are countries like Spain, Italy, Greece, and Tunisia. There are different types of olive oils available in the market.

      The process of extraction of olive oil depends on crushing olives and then separating the oil from the fruit pulp under elevated pressure and the oil has a higher content of free fatty acids.

A refining process is meant to purify the extracted oil from any residual solvent and other impurities. Refined olive oil is devoid of vitamins, polyphenols, phytosterols, and other low molecular natural ingredients.

Olive oil is broadly classified into four grades:

(1) Extra virgin olive oil is derived from first pressings of olive fruits that possesses excellent taste and odour and has a free fatty acid content, expressed as oleic acid, of not more than 0.8 grams per 100 grams;

(2)  Virgin olive oil  is derived from first pressings that possesses good taste and odour and has a free fatty acid content of not more than 2.0 grams per 100 grams;

(3) Pure, or edible, a mixture of refined and virgin;

(4) Refined, or commercial, refined ‘ lampante’.

Olive oil is sometimes mixed with other vegetable oils, but this is not legally valid in all countries; but allowed in some countries. Adulteration can be detected by chemical analysis

     Health benefits

Nutritional facts 

   The olive oil that goes through the least amount of processing to make is extra virgin olive oil (EVOO). Because of this, EVOO has more nutrition than virgin or refined olive oils do. The chemical composition of olive oil varies depending on the extraction technology that is applied in order to obtain oil form the fruits. Extra virgin olive oil due to its low yield is more expensive than other types of olive oil, but it is highly nutritive as it contains the highest level of polyphenols.

    The predominant fatty acid present in olive oil triglycerol is monounsaturated oleic acid (up to 83% w/w). There is also palmitic acid, linoleic acid, stearic acid, and palmitoleic acid making up the remainder of olive oil triglycerols.

 Olive oil is a source of at least 30 phenolic compounds. The major phenolic compounds in olive oil are oleuropein, hydroxytyrosol and tyrosol. In olive oil, the content of polyphenols ranges from 50 to 1000 mg/kg. The polyphenol content depends on the ripeness of olives, extraction technology, storage or packaging processes. The phenolic compounds present in olive oil are strong antioxidants and free radical scavengers[3].

·        Good for cardiovascular health

Olive oil is a key ingredient of Mediterranean diet, which is considered as highly beneficial for cardiovascular health. Olive oil helps to protect your heart and blood vessels from clots and heart attacks.

Olive oil is rich in antioxidants, including polyphenols, and in healthy monounsaturated fatty acids. Studies of olive oil have shown that its consumption in the diet, particularly in the form of extra-virgin olive oil, is associated with lowered risk of cardiovascular disease and type 2 diabetes mellitus. 

·        Olive oil has anti-inflammatory properties

It helps to prevent brain inflammation, skin inflammation etc.

·        Antioxidant potential

The polyphenols of olive oil can prevent or neutralize oxidative stress caused by free radicals in your body. They are effective free radical scavengers. Olive oil can protect against the damage caused by various free radicals in the body. It helps to prevent age related  oxidative damage to your body & skin.

·        Helps nervous system and brain

Olive oil prevents amyloid-beta plaque formation, which are characteristic of Alzheimer disease. Studies in animals have shown that a diet rich in olive oil can in fact help protect against memory loss and learning impairment associated with dementia. Therefore olive oil is important for neuronal health.

·        Anticancer properties

Anticancer potential of olive oil is linked with the antioxidant activity of phenolic and polyphenolic compounds present in it .Oleuropein, tyrosol, hydroxytyrosol, verboscoside, ligustroide, demethyleuropein were all proven to protect against the coronary artery disease and cancer.

       Research findings about health benefits of olive oil

·        Studies  have demonstrated that antioxidants  function against oxidation of LDL[bad cholesterol] .  Phenolic  compounds present only in extra virgin olive oil, may contribute to the  antioxidant capacity .

·        Hydroxytyrosol (HT) belongs to polyphenols, which are abundant in olives .Free radical scavenging properties of this compound has been convincingly confirmed by studies [7].

·        Phenolic compounds (oleuropein, protocatechuic acid) of virgin olive oil have also been shown to inhibit macrophage-mediated LDL oxidation [8]

·        Some of the nutrients in olive oil can fight harmful bacteria, Helicobacter pylori of stomach which can cause ulcers and sometimes even cancer. Compounds in olive oil help destroy the bacteria.

·        Olive oil consumption was proven to prevent from colorectal cancer, breast cancer and skin cancer [9].

·        Antioxidant  polyphenols (hydroxytyrosol, oleuropein) makes virgin olive oil relatively stable and resistant to oxidation, and thus minimizing the risk of formation of potentially carcinogenic products of lipid peroxidation upon storage.

·        There are so many studies confirming the anticancer activity of oleuropein, as observed in human cancer cell lines, such as: breast adenocarcinoma, melanoma, urinary bladder carcinoma, colorectal adenocarcinoma. Oleuropein polyphenol of olive oil  can induce apoptosis in breast cancer cells[4].

·        It has also been demonstrated that daily consumption of olive oil phenolics protect from DNA oxidation in postmenopausal women [10]

How to include olive oil in your diet?

Olive oil  very much beneficial to your health due to its antioxidant, anti inflammatory and anti carcinogenic properties. It is an excellent source of polyphenol antioxidants and an important component of Mediterranean diet.

You can include olive oil in your diet to protect against heart attacks, strokes and some types of cancers.

Some of the foods in which  olive oil added as a key ingredient  are listed here.

 Some of the foods in which olive oil added as a key ingredient  are listed here.

(1) Basil Pesto

        Pesto is a simple sauce that can transform dishes of all sorts with its bright herbal flavors. This classic basil version is fresh and delicious.

(2) Mediterranean Baked Chicken Breast

         Chicken breast gets marinated in Mediterranean flavors like lemon juice, olive oil, and herbs and then baked in the oven.

(3) Asparagus fry

asparagus stir-fried with garlic and olive oil . A squeeze of fresh lemon juice just before serving adds the flavor.

(4) Vegetable Salad with Olive Oil Dressing

(5) Grilled Vegetable Salad With Olive Oil dressing

(6) Pork Caesar Salad

(7) Beet Orange and Walnut Salad

(8) Avocado Tomato Salad

(9) Brussel Sprouts Caesar Salad

(10)        Mediterranean White Bean Salad

References

1.     https://www.britannica.com/plant/olive-plant

2.     https://www.britannica.com/topic/olive-oil

3.     https://pubmed.ncbi.nlm.nih.gov/12550060/

4.     https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5877547/

5.     Protective effect of the phenolic fraction from virgin olive oils against oxidative stress in human cells

https://pubmed.ncbi.nlm.nih.gov/12381144/ 

6.     https://pubmed.ncbi.nlm.nih.gov/8645356/

7.     https://pubmed.ncbi.nlm.nih.gov/19725535/

8.     https://pubmed.ncbi.nlm.nih.gov/15051826/

9.     https://pubmed.ncbi.nlm.nih.gov/28071050/