Summary of questions. The answers are further below.
Α. Why do we say extra virgin olive oil? What is the difference between virgin olive oil and ordinary olive oil?
B. What are the health benefits of extra virgin olive oil?
C. What are the quality criteria for extra virgin olive oil?
D. Black or green olives? What is their difference?
E. health claim for the extra virgin olive oil
A. Why is it called extra virgin olive oil? What is the difference between virgin olive oil and ordinary olive oil?
There are 3 main categories of olive oil on the supermarket shelves:
- extra virgin olive oil is produced only by natural and mechanical processes, with perfect aroma and taste, with free oleic acidity not exceeding 0.8% and with other characteristics in accordance with those provided by the European Community Regulation 2568/91.
- Virgin olive oil is produced only by physical and mechanical processes, with good organoleptic characteristics, with a free oleic acidity not exceeding 2.0% and with other characteristics in accordance with those provided for by regulation 2568 / 91 of the European Community.
- Olive oil: “is the mixture of refined olive oil (by chemical methods) and edible virgin olive oil whose free oleic acidity does not exceed 1%. Refined olive oil is obtained by refining, that is to say by chemical methods (neutralization, deodorization, discoloration) of the disadvantaged virgin olive oil ”.
According to scientific research, extra virgin olive oil contains a higher amount of polyphenols, which are substances that strengthen the human immune system. Its low content of oleic acid also protects the human body and improves the functioning of the cardiovascular system in humans.
Ordinary olive oil is a chemical processing product and therefore of very low quality and low content of ingredients beneficial to health.





B. What are the health benefits of extra virgin olive oil?
- Olive oil is high in healthy monounsaturated fats. About 14% of the oil is saturated fat, while 11% is polyunsaturated, like omega-6 and omega-3 fatty acids. But the predominant fatty acid in olive oil is a monounsaturated fat called oleic acid, which accounts for 73% of the total oil content. Studies suggest that oleic acid reduces inflammation and may even have beneficial effects on genes linked to cancer. Monounsaturated fats are also quite resistant to high heat, which makes extra virgin olive oil a healthy choice for cooking.
- Olive oil contains high amounts of antioxidants.
Extra virgin olive oil is quite nutritious. Besides its beneficial fatty acids, it contains modest amounts of vitamins E and K. But olive oil is also loaded with powerful antioxidants. These antioxidants are biologically active and may lower your risk of chronic disease. They also fight inflammation and help protect your blood cholesterol from oxidation – two benefits that may lower your risk of heart disease. - Olive oil has strong anti-inflammatory properties. Chronic inflammation is believed to be a major driver of diseases such as cancer, heart disease, metabolic syndrome, type 2 diabetes, Alzheimer’s disease, arthritis and even obesity. Extra virgin olive oil can reduce inflammation, which may be one of the main reasons for its health benefits. The main anti-inflammatory effects are mediated by antioxidants. The main one is oleocanthal, which has been shown to work similarly to the anti-inflammatory drug ibuprofen (10 Trusted Source). Some scientists estimate that oleocanthal in 3.4 tablespoons (50 ml) of extra virgin olive oil has a similar effect at 10% of the adult dose of ibuprofen (11 Trusted Source). Research also suggests that oleic acid, the main fatty acid in olive oil, may reduce the levels of important inflammatory markers like C-reactive protein (CRP). A study also showed that the antioxidants in olive oil can inhibit certain genes and proteins that cause inflammation.
- Olive Oil May Help Prevent Strokes. Stroke is caused by a disruption in blood flow to your brain, either due to a blood clot or bleeding. In developed countries, stroke is the second most common cause of death, just behind heart disease. The relationship between olive oil and stroke risk has been widely studied. A large review of studies involving 841,000 people found that olive oil was the only source of monounsaturated fat associated with a reduced risk of stroke and heart disease. In another review of 140,000 participants, those who consumed olive oil had a much lower risk of stroke than those who did not.
- Olive oil protects against heart disease. Heart disease is the most common cause of death worldwide. Observational studies carried out a few decades ago showed that heart disease is less common in Mediterranean countries. This has led to extensive research into the Mediterranean diet, which has now been shown to significantly reduce the risk of heart disease. Extra virgin olive oil is one of the key ingredients in this diet, protecting against heart disease in several ways. It reduces inflammation, protects “bad” LDL cholesterol from oxidation, improves the lining of your blood vessels, and may help prevent excessive blood clotting. Interestingly, it’s also been shown to lower blood pressure, which is one of the biggest risk factors for heart disease and premature death. In one study, olive oil reduced the need for high blood pressure medication by 48%. Dozens, if not hundreds, of studies indicate that extra virgin olive oil has powerful benefits for your heart. If you have heart disease, a family history of heart disease, or any other major risk factor, you may want to include a lot of extra virgin olive oil in your diet.
- Olive oil is not associated with weight gain and obesity. Eating excessive amounts of fat leads to weight gain. However, many studies have linked the Mediterranean diet, which is rich in olive oil, to favorable effects on body weight. In a 30-month study of over 7,000 Spanish students, consuming a lot of olive oil was not linked to an increase in weight. What’s more, a three-year study of 187 participants found that a diet high in olive oil was linked to increased levels of antioxidants in the blood, as well as weight loss.
- Olive oil can fight Alzheimer’s disease. Alzheimer’s disease is the most common neurodegenerative disease in the world. One of its main characteristics is a build-up of so-called beta-amyloid plaques inside your brain cells. A study in mice has shown that a substance in olive oil can help remove these plaques. Additionally, a human study indicated that a Mediterranean diet high in olive oil was beneficial for brain function. Keep in mind that more research is needed on the impact of olive oil on Alzheimer’s disease.
- Olive oil may reduce the risk of type 2 diabetes. Olive oil appears to be very protective against type 2 diabetes. Several studies have linked olive oil to beneficial effects on blood sugar and insulin sensitivity. A randomized clinical trial involving 418 healthy people recently confirmed the protective effects of olive oil. In this study, a Mediterranean diet rich in olive oil reduced the risk of type 2 diabetes by more than 40%.
- Antioxidants in olive oil have anti-cancer properties. Cancer is one of the most common causes of death in the world. People in Mediterranean countries have a lower risk of certain cancers, and many researchers believe olive oil may be the reason. The antioxidants in olive oil can reduce oxidative damage from free radicals, which are believed to be one of the main drivers of cancer. Numerous test-tube studies show that compounds in olive oil can fight cancer cells. More research is needed to determine if olive oil actually lowers your cancer risk.
- Olive Oil May Help Treat Rheumatoid Arthritis. Rheumatoid arthritis is an autoimmune disease characterized by deformed and painful joints. While the exact cause is not well understood, it implies that your immune system mistakenly attacks normal cells. Olive oil supplements appear to improve inflammatory markers and reduce oxidative stress in people with rheumatoid arthritis. Olive oil seems particularly beneficial when combined with fish oil, a source of anti-inflammatory omega-3 fatty acids. In one study, olive and fish oil significantly improved grip strength, joint pain, and morning stiffness in people with rheumatoid arthritis. Olive oil has antibacterial properties
- Olive oil contains many nutrients that can inhibit or kill harmful bacteria. One of them is Helicobacter pylori, a bacteria that lives in your stomach and can cause stomach ulcers and stomach cancer. Test-tube studies have shown that extra virgin olive oil fights eight strains of this bacteria, three of which are resistant to antibiotics. A study in humans suggested that 30 grams of extra virgin olive oil, taken daily, can clear Helicobacter pylori infection in 10-40% of people in as little as two weeks.
Make sure you get the right type Buying the right kind of olive oil is extremely important.
Extra virgin olive oil retains some of the antioxidants and bioactive compounds in olives. For this reason, it is considered healthier than the more refined variety of olive oil. Therefore, examine the labels carefully to make sure that you are getting real extra value.
Original Link: https://www.healthline.com/nutrition/11-proven-benefits-of-olive-oil#TOC_TITLE_HDR_11


C. What are the quality criteria for extra virgin olive oil?
The criteria for evaluating olive oil are mainly 4, as follows:
The free oleic acidity
In extra virgin olive oil, the free acidity must not exceed 0.8%
Number of peroxides
The number of peroxides is an indicator of the degree of oxidation of an oil at the primary stage, based on the detection of peroxides as indicators of tangency.
UV absorption
It is measured by two constants named K232 and K270 (or K268).
The K232 shows the intermediate percentage of oxidation of the components of olive oil, when this is verified in the chromatograph with a wavelength of 232 nm. If the price of the K232 is high, it is due to a scary, very slow or not modern production process.
The K270 (or K268) indicates the percentage reduction in resistance to oxidation when olive oil is checked on the chromatograph with a wavelength of 270 nm. The price of this constant depends on the freshness of the olive oil. Old olive oils or blends with old olive oils have increased the prices of K270.
Organoleptic evaluation of olive oil
To understand how necessary the “organoleptic” (tasting) evaluation of an olive oil is, we must of course first define what it means exactly and what its value and usefulness is. In simple terms, ‘organoleptic’ (tasting) evaluation means examining an olive oil, after first smelling it (odor) and then tasting it by putting a small amount in our mouth (taste) in order to identify its special characteristics.
To correctly determine these characteristics, one must first smell a small amount of olive oil in a small glass and then try it by slowly swallowing another small amount (for example a teaspoon). This process will allow us first to see if the olive oil has a defect (“negative characteristic”) and then describe which “positive characteristics” and to what extent have we identified. The (good) positive characteristics of olive oil, according to the definition given and used worldwide by the International Olive Council, are three in number: “fruity”, “bitter” and “spicy”. A good olive oil should have these three characteristics, which are evaluated and rated by trained judges (olive oil tasters). The higher the score attributed to them, and in particular to the first, called “fruity”, the better the characterization of an olive oil.
But what is an “organoleptic defect”? It is a bad smell or bad taste that can be present in olive oil and can come from eg. pickling, moldy olives in the bags, when they have gone to the mill and waited stacked for 5 or 10 days, or usually have an unpleasant bad taste which may be due to fifteen other reasons related to the production, the preservation process etc. Warning: If an olive oil has an organoleptic defect, it cannot be called “extra virgin”! It will be classified as “virgin” if the defect is not serious or, if it is serious, it will have to be sent for serious industrial treatment to the refinery in order to get rid of all the bad characteristics and to be sold with the indication on the label “olive oil” (and not extra virgin!).
Text by Vassilis Fratzolas, Greek expert in olive oil.





D. Black or green olives? What is their difference?
First of all, it must be said that black olives are just a more mature stage than green olives. The olives on the tree first turn green, then gradually turn purple, and at the end they ripen completely, acquiring a deep black color.
Their nutritional value is more or less the same. A 15 gram serving of black olives contains 25 calories, while the corresponding amount of green 20 calories. Both contain 2 grams of fat (0.5 grams of saturated or polyunsaturated fat and 1.5 grams of monounsaturated fat). They contain less than 0.5 grams of protein, 1 gram of carbohydrates and 0.5 grams of fiber. Finally, they contain small amounts of vitamins and minerals and more precisely 2% of our body’s daily requirements for vitamin E and 1% for vitamin A.
The only difference is the amount of sodium they contain. Five black olives contain about 115-125 milligrams of sodium, or 8% of this recommended daily allowance. The same serving of green olives contains 218 to 360 milligrams of sodium, or 14 to 24% of the same guideline. So we conclude that black people are -in a sense- better, because a high amount of sodium is not good for our body.



E. health claim for the extra virgin olive oil
“The polyphenols in olive oil help protect blood lipids against oxidative stress as part of a varied and balanced diet”
European Regulation 432/2012 (L 136 / 25.5.2012 p. 26. This health claim can only be used for olive oil containing at least 250 mg of polyphenols per 1 kg of olive oil and recommended dose is at least 20 grams of olive oil per day.
