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The Real Story on OLIVE OIL

Feb 15, 2005

Canola and olive oil are the two most widely used cooking oils in the world today. It wasn’t always this way and it is important to understand how this change occurred, because it wasn’t always for health reasons that this shift took place. Fred Pescatore, MD, MPH, CCN author of The Hampton’s Diet explains what happened, as he helps us learn about The Science of Fats, Fatty Acids and Edible Oils

Canola and olive oil are the two most widely used cooking oils in the world today. It wasn’t always this way and it is important to understand how this change occurred, because it wasn’t always for health reasons that this shift took place. For years, we were stuck in the mire of polyunsaturated fats being healthy for us and these two oils were relegated to the back shelf. However, once the shift to monounsaturated fats and omega-3 fatty acids came to be, these two oils quickly rose to prominence. Since many of you are probably sitting there pretty smugly thinking you are being so healthy because these are the only two oils you use; and, since I have spent so much time saying they aren’t, this is the chapter that explains my reasoning. It is a pretty fascinating story so sit back and read this like a good mystery.


Carrie, a 44 year old mother of two teenage children came to see me because she was exhausted all the time. She worked and raised her children so she had plenty to be tired about. She had always been a health nut and during our first visit when we discussed some of the basics, the conversation came around to cooking oils. She held up her hand and said don’t worry there doc, I’ve got that under control – I only use olive oil when I am cooking and canola oil for salad dressings.

Several years ago I would have applauded her for her heightened awareness of fats and oils. Now that I know the benefits of Macadamia nut oil, I knew that she had only part of the story. I explained the problems associated with both olive and canola oils and she was shocked, but happy to make the switch as she really wanted to feel better.

Within two weeks, Carrie came back to the office reporting renewed vigor and not having to sleep as much. By the end of six weeks, she felt like her old self and had lost those troublesome ten pounds that she just couldn’t get rid of. She loved that the diet was so easy to follow and could not believe how delicious all of her old recipes tasted once she made the switch to Macadamia nut oil.

Before we get too far into the details, I want to make one thing perfectly clear: I think olive oil is a far superior product to canola oil; and olive oil can even be used on occasions. Canola oil on the other hand is an abomination and should be eliminated from your diet forever. Let me tell you why.

Olive Oil Facts

Since olive oil comes in so many different varieties and price ranges, it is important to have a clear understanding of what makes it so. To make matters worse, in the gourmet world, olive oil will soon overtake wine as the most complex decision to have to make. Like wine, olive oil varies in flavor, color, and aroma depending on the variety of olive used, the soil and climate in which it is grown, when it was picked, and how it was pressed. But, unlike wine, all of these variations make a big difference when it comes to the health benefits of the olive oil.

Because olive oil is such a large market, and comes from various regions throughout the world, there is much fraud and consumer confusing practices that occur. There are some internationally recognized guidelines, but that is about it when it comes to regulation. Spain is the largest producer of olive oil, but olive oil can come from many other countries, including Greece, Italy, Tunisia, Turkey, the United States, and elsewhere. Although Spain may be the largest producer, Italy still captures the attention of the world market as having the finest grade of olive oil. According to the North American Olive Oil Association, U.S. sales of olive oil exceeded those of all other cooking oils in 2000, bringing in 35% of the $1.2 billion in sales.

Olives are harvested at different times of the year, depending on the frost conditions of the region. In areas where there is no frost, the olives are harvested in January or February. This is most common in the southern regions of Italy. In the frostier regions, harvest is in November and December. To ensure the highest quality, olives should be picked just before they ripen and milled that same day as the olives will begin to ferment within 3 to 4 hours after harvest. The best olive oils are made from those olives that have been harvested by being hand-picked or by beating the branches with a stick. It takes roughly 1500 – 2000 olives to make a quart of oil.

Tuscany and Umbria produce greener, more fruity and pungent flavored oils because these are harvested and produced from olives that are the most immature. Oils from Liguria, Provence (in France) or Apulia are more golden in hue, are sweeter and have a nuttier flavor. These are the more southern varieties, produced from a riper olive. All of these characteristics play a role in the health benefits of the oil, so pay attention.

Olive oils are processed in a variety of different ways and the processing is crucial.
Harvest time: less ripe is sharper tasting and healthier
Harvesting Method: less ripe by hand; the more ripe olives fall to the ground and are caught into nets.
Grinding methods: stone wheels or stainless steel grinders
Oil extraction: centrifuge, hydraulic press or a high-tech system called Sinolea
Refining: solvents, heating, and blending

The combination of these factors will determine the quality, flavor and the health benefits of the oil. Therefore, the labeling of these bottles is important. Don’t be fooled into thinking you are getting a good oil simply because it says it is stone pressed. A stone pressed oil can still undergo a poor extraction method and lose its health properties.

Because of all these factors, the creation of a superior olive oil is similar and more expensive than making a good wine. Wine can be manipulated during the fermentation process, but olive oil, can not. The flavor and texture comes from the olive alone; and, the oil can be made blander but not more flavorful. After the olives are harvested, they must be cleaned and ground into a paste and then pressed to extract the water and the oil from the fruit. The liquid is then spun to separate the heavier water from the oil. The extracted oil is then refined and processed.

Losing Their Virginity

There are some internationally recognized guidelines, but they may vary from producer to producer. Virgin olive oils can be broken down into extra-virgin and virgin.

Virgin – olive oil that must be obtained from olives exclusively pressed from physical means such as stone pressing or hydraulic pressing under conditions that do not lead to physical decay of the oil is defined as virgin. This oil can not undergo the rest of the refining process and solvents may not be used. The oil can undergo washing, decanting, centrifugation and filtering. Decanting simply means that after the oil has been extracted, it is stored in urns to allow for the olive skin and other pulp particles to settle out. This gives the oil a lighter flavor and texture and is sometimes sold as, “light.” This has an acidity level greater than 1% but less than 2%.

Extra Virgin – this is made from olives just like the virgin ones, with the only difference being in the amount of acidity or free fatty acids that are present in the final product. Extra virgin can have no more than a 1% acidity level. These oils have the highest levels of polyphenols and omega-3 fatty acids and the lowest levels of saturated fats and omega-6 fatty acids. That is, if they are estate produced and not mass market produced. Any product further down the olive oil food chain starts to have a poorer fatty acid profile.

Pure Olive Oil – this is now known as plain olive oil although you still may see the word, “pure” on the label. This is virgin olive oil that doesn’t taste quite right because of the higher acidity level and must be blended with a better grade virgin oil in order to be palatable. This oil has been processed and the level of monounsaturated fat is very variable as is the color, aroma, and flavor depending on how much regular virgin oil has been blended in by the particular manufacturer. Infused oils are generally made from this type of olive oil since a good high quality olive oil will have a very distinct flavor that would overpower most of the infused flavors. This is not true with Macadamia nut oil as the infused varieties are made from the same grade oil as the regular version – yet another advantage to Macadamia nut .

Olive Pomace Oil – this is usually used in the restaurant industry. Therefore, if you think you are doing something healthy by eating in restaurants that only use olive oil, think again. Unless the restaurant is really high end, this is the oil they are going to be using – something without a good fatty acid profile, due to its level of processing. This type of oil is derived from the part of the olive that is left after it has been pressed or centrifuged. This is known as the pomace and solvents may be used to further extract more oil. It is then refined for palatability and blended with small amounts of virgin oil.

Light Olive Oil – this is usually nothing more than highly refined olive oil that has been steamed, bleached with peroxide, and then blended with small amounts of extra virgin olive oils.

So, basically all olive oils are produced as virgin oils. The best ones are those that have the least amount of free fatty acids, or are lowest in acidity. Those are sold as extra virgin. If the acidity level is above a certain percentage, greater than 2%, than the oil must be further processed and blended to get a product that is edible and palatable. Those are sold as olive oil or “pure” olive oil. If it falls somewhere in between, then it is sold as virgin. Therefore, the only designation that really means anything is the extra-virgin one as that means highest quality. This highest quality oil is then further sub-divided into the amount of free fatty acids or acidity that is present.

Acidity Levels

This is the most fundamental quality measurement of an edible oil. This is what distinguishes extra virgin from any other grade of olive oil. The freshest olive oil made from unripe olives grown in cooler climates normally have a low acidity level of about 0.5% or less. The acidity is the result of a breakdown of naturally occurring triacylglycerols due to a chemical reaction in which free fatty acids are formed. The lower the acidity, the higher will be the polyphenol and antioxidant concentrations.

This level has been adopted by the edible oil industry as an effective measure of over-ripeness and damage from poor handling and processing. This carelessness can lead to a further breakdown of the triacylglycerides into free fatty acids. Since these are tri or three molecules held together, the breakdown products can be either diacylglycerols or monoacylglycerols. The usual cause of the higher free fatty acid content is the delay between harvesting and extraction or if the olive has been bruised, damaged or diseased.
The free fatty acidity is thus a direct measure of the quality of the oil, and reflects the care taken from harvest to extraction to the sale and consumption of the oil. Measurement of FFA (free fatty acidity) is a very simple procedure and is done on all edible oils. The degree of free fatty acids affects the smoke point of an oil too. This is a reflection of how stable the oil is since the lower the free fatty acidity; the less damage has been done to the oil. Macadamia nut oil has a free fatty acidity less than 0.5%. Macadamia nut oil matches olive oil in every aspect of its healthiest characteristics and surpasses it in all of them. There really is no match if you want to be monounsaturated rich and lose weight and get healthy with The Hamptons diet.

Peroxides: Peroxides are the primary products of oxidation of olive oil. The more the oil has gone rancid or oxidized, the more the peroxides. This is true of any edible oil and is a good measure of the healthiness of an oil product. The maximum peroxide value of Macadamia nut oil is 2.0. The average peroxide value of olive oil is 3.5

Olive Oil Mythology

Or should I say fraud? As I previously explained, the labeling of extra virgin oil is done by measuring the acidity level. Some manufacturers are blending refined and virgin oils to achieve a better acidity level so they can claim their product is extra virgin. Still others are sending their product to Italy to be bottled so it can be labeled as a product of that country. The fact that the label says, “extra virgin” doesn’t mean anything anymore. There are very few truth in labeling laws for the olive oil industry and there is no differentiation available for the premium extra virgin and the other extra virgins. Anyone can basically put anything they want on their label. For example, “cold-pressed” is an obsolete term, yet still used as most consumers consider this to be the gold standard in oil pressing. Due to a recent law suit, the manufacturers are required to list the oils’ country of origin, at least.

The purity of an olive oil is also of utmost importance since research shows that although blended oils may meet technical and taste standards, they don’t contain the full health benefits of a real pure olive oil. Also, oils from fully ripe olives, olives grown in poor soil and those grown in hotter climates have higher saturated fat levels and lower polyphenol concentrations that oils made from unripe olives and cooler climates.

Because of the high-tech machinery, the oil is extracted in minutes from the olives. The technology allows some manufacturers to blend refined oils with extra virgin oils to get just the right amount of low acidity. All sorts of mixing goes on amongst the various types of olive oils I described. This practice is perfectly legal as long as it says so on the label – unfortunately, it does not. Extra virgin oils are labeled as such when they are not.

An interesting additive that is cheaper to manufacture is hazelnut oil. It is very similar to olive oil which makes it the perfect additive for unethical manufacturers. It is so similar that it is difficult to detect it even when analyzed. Canola oil and other cheap oils are added too, but it is much easier to tell the difference when chemically tested. Certain companies are notorious for blending olive oil with hazelnut oil and the duplicity occurs at ports around the world. The United States does do random checking of these oils. However, even the olive oil distributors inherently know what they are dealing with one dealer exclaiming, “the customers know from the lower price that I can’t possibly be selling them 100% extra virgin olive oil,” but they buy it anyway. Now that you know these vast differences, I bet you are going to think differently before buying a cheap olive oil.

If you want the healthiest extra virgin olive oil, look beyond the labels and ignore the hype for cold-pressed types of oil. Read the fine print and check the bottling date, acidity level, and production region. With Macadamia nut oil, you never have to do any of that. Macadamia nut oil, by comparison has a free fatty acid content that averages 0.5% and an acid level that never exceeds 1%. Therefore, it is comparable to the finest estate produced extra-virgin olive oils that are at least double the price. Yet, Macadamia nut oil still has by far, the best fatty acid profile and is still more monounsaturated rich than olive oil, no matter what the price.

To ensure that you are buying the highest quality olive oil that you can, simply look for the following attributes:
Acidity level – the lower the acidity level, the better the quality of oil. The maximum for Macadamia nut oil is 1%. The maximum for estate bottled extra virgin olive oil should also be 1%. However, there are still more monounsaturated fats in Macadamia nut oil.
Date – olive oil is best used within a year of being bottled with two at the most. Most mass marketed and cheap olive oils are old and should not be used. Macadamia nut oil has an optimum shelf life stability of two years but if kept in a cool place, can last for five years.
Location – this is required to be listed on olive oil bottles. The cooler the region and the more unripe the olive, the healthier is the oil – it will have higher levels of oleic acid – the monounsaturated fat that is healthy. Macadamia nut oil is made from nuts that are grown and harvested in ideal conditions – Australia and making it highest in monounsaturated fats; not Hawaii which is too tropical to get the best fatty acid profile.

The latest trend in olive oil is for estate bottled, extra virgin, single varietal oils. Similar to wine, each olive will have a distinctive flavor and be prized for different dishes. These are quite expensive but should be the ones that you use if you choose to use olive oil. They will be the ones with the highest smoke points, lowest free fatty acid levels, lowest acidity levels, and higher in monounsaturated fat. The ordinary olive oils that most of us buy are poor quality, blended oils. When that occurs, it is impossible to tell what health benefits one is getting because it is impossible to know the origin of the oil, as there are no labeling laws that require the identification of blended oils.

For simplicity sake, just know that it is impossible to get a good quality extra-virgin product that is inexpensive. An extremely low price should make you question the quality and even the purity of the oil. Most good ones will cost about $20 for 500ml and many more will cost much more than that. Macadamia nut oil is a bargain in comparison to this.