Olive oil, extra virgin

Anyone coming from the Mediterranean region of the world would tell you about the health benefits, as well as the wonderful flavor, of a good dose of olive oil on salads, pasta, fish and almost anything else. Fortunately, it is available throughout the year to satisfy taste buds and promote good health. What's New and Beneficial about Extra Virgin Olive Oil The quality of olive oil production—especially the stage of pressing—really does make a difference when it comes to health benefits. Recent studies have compared the anti-inflammatory benefits of extra virgin olive oil (EVOO) obtained from the first pressing of the oil to the anti-inflammatory benefits of virgin olive oils (non-EVOO) obtained from later pressings. What researchers found was an ability of EVOO to lower inflammatory markers in the blood when non-EVOOs were unable to do so. (Study measurements included blood levels of thromboxane A2, or TXA2, and leukotriene B2, or LBT2.) This ability of extra virgin olive oil to help protect against unwanted inflammation is not surprising, since EVOO is known to contain stronger concentrations of phytonutrients (especially polyphenols) that have well-known anti-inflammatory properties. Mediterranean Diet studies have long associated olive oil intake with decreased risk of heart disease. However, a recent group of studies has provided us with a fascinating explanation of olive oil's cardioprotective effect. One of the key polyphenols in olive oil—hydroxytyrosol (HT)—helps protect the cells that line our blood vessels from being damaged by overly reactive oxygen molecules. HT helps protect the blood vessel cells by triggering changes at a genetic level. The genetic changes triggered by HT help the blood vessel cells to enhance their antioxidant defense system. In other words, olive oil supports our blood vessels not only by providing antioxidants like like vitamin E and beta-carotene. Olive oil also provides our blood vessels with unique molecules like HT that actually work at a genetic level to help the cellular walls of the blood vessels remain strong. Olive oil has long been recognized for its unusual fat content. This plant oil is one of the few widely used culinary oils that contains about 75% of its fat in the form of oleic acid (a monounsaturated, omega-9 fatty acid). In terms of monounsaturated fat, the closest common culinary oil to olive is canola oil, with about 60% of its fat coming in monounsaturated form. By contrast, the fat in soybean oil in only 50-55% monounsaturated; in corn oil, it's about 60%; in sunflower oil, about 20%; and in safflower oil, only 15%. When diets low in monounsaturated fat are altered to increase the monounsaturated fat content (by replacing other oils with olive oil), research study participants tend to experience a significant decrease in their total blood cholesterol, LDL cholesterol, and LDL:HDL ratio. Recent research studies have taken these heart-healthy effects of olive oil one step further. Olive oil's monounsaturated fat content (specifically, its high level of oleic acid) has now been determined to be a mechanism linking olive oil intake to decreased blood pressure. Researchers believe that the plentiful amount of oleic acid in olive oil gets absorbed into the body, finds its way into cell membranes, changes signaling patterns at a cell membrane level (specifically, altering G-protein associated cascades) and thereby lowers blood pressure. To our knowledge, this is the first time that the monounsaturated fat content of olive oil has been linked not only to cholesterol reduction, but also to reduction of blood pressure. Cancer prevention has been one of the most active areas of olive oil research, and the jury is no longer out on the health benefits of olive oil with respect to cancer. Twenty-five studies on olive oil intake and cancer risk—including most of the large-scale human studies conducted up through the year 2010—have recently been analyzed by a team of researchers at the Mario Negri Institute for Pharmacological Research Institute in Milan, Italy. Firmly established by this research team were the risk-reducing effects of olive oil intake with respect to cancers of the breast, respiratory tract, upper digestive tract and, to a lesser extent, lower digestive tract (colorectal cancers). These anti-cancer benefits of olive oil became most evident when the diets of routine olive oil users were compared with the diets of individuals who seldom used olive oil and instead consumed diets high in saturated added fat, especially butter.

This chart graphically details the %DV that a serving of Olive oil, extra virgin provides for each of the nutrients of which it is a good, very good, or excellent source according to our Food Rating System. Additional information about the amount of these nutrients provided by Olive oil, extra virgin can be found in the Food Rating System Chart. A link that takes you to the In-Depth Nutritional Profile for Olive oil, extra virgin, featuring information over 80 nutrients, can be found under the Food Rating System Chart.

• Health Benefits
• Description
• History
• How to Select and Store
• Tips for Preparing and Cooking
• How to Enjoy
• Individual Concerns
• Nutritional Profile
• References

Health Benefits

Thanks to its status as a spotlight food in the Mediterranean Diet, and thanks to extensive research on its unique phytonutrient composition, olive oil has become a legendary culinary oil with very difficult-to-match health benefits. Among its extensive list of phytonutrients, no single category of nutrients is more important than its polyphenols. The polyphenol content of this delicious oil is truly amazing! The list below shows some of the key polyphenols found in olive oil, organized by their chemical category:

• Simple Phenols
  • tyrosol
  • hydroxytyrosol
• Terpenes
  • oleuropein
  • ligstroside
• Flavones
  • apigenin
  • luteolin
• Hydroxycinnamic acids
  • caffeic acid
  • cinnamic acid
  • ferulic acid
  • coumaric acid
• Anthocyanidins
  • cyanidins
  • peonidins
• Flavonols
  • quercetin
  • kaempferol
• Flavonoid glycosides
  • rutin
• Lignans
  • pinoresinol
• Hydroxybenzoic acids
  • vanillic acid
  • syringic acid

Most of the polyphenols in this list have been shown to function both as antioxidants and also as anti-inflammatory nutrients in the body. The very number and variety of polyphenols in olive oil helps explain the unique health benefits of this culinary oil.

Anti-Inflammatory Benefits

It's unusual to think about a culinary oil as an anti-inflammatory food. Plant oils are nearly 100% fat, and in a general dietary sense, they are typically classified as "added fats." Intake of too much added dietary fat can be a problem for many reasons—including reasons involving unwanted inflammation. So it's pretty remarkable to find a culinary oil that's repeatedly been shown to have anti-inflammatory properties and provide health benefits in the area of unwanted inflammation. Yet that's exactly the research track record that describes extra virgin olive oil.

The anti-inflammatory strength of olive oil rests on its polyphenols. These anti-inflammatory compounds include at least nine different categories of polyphenols and more than two dozen well-researched anti-inflammatory nutrients. Research has documented a wide variety of anti-inflammatory mechanisms used by olive oil polyphenols to lower our risk of inflammatory problems. These mechanisms include decreased production of messaging molecules that would otherwise increase inflammation (including TNF-alpha, interleukin 1-beta, thromboxane B2, and leukotriene B4); inhibition of pro-inflammatory enzymes like cyclo-oxygenase 1 and cyclo-oxygenase 2; and decreased synthesis of the enzyme inducible nitric oxide synthase.

In heart patients, olive oil and its polyphenols have also been determined to lower blood levels of C-reactive protein (CRP), a widely used blood measurement for assessing the likelihood of unwanted inflammation. They have also been found to reduce activity in a metabolic pathway called the arachidonic acid pathway, which is central for mobilizing inflammatory processes.

These anti-inflammatory benefits of extra virgin olive oil do not depend on large levels of intake. As little as 1-2 tablespoons of extra virgin olive oil per day have been shown to be associated with significant anti-inflammatory benefits.

Cardiovascular Benefits

Many different cardiovascular problems—including gradual blocking of the arteries and blood vessels (called atherosclerosis)—have their origin in two unwanted circumstances. The first of these circumstances is called oxidative stress. Oxidative stress means too much damage (or risk of damage) from the presence of overly reactive oxygen-containing molecules. One of the best ways to help avoid oxidative stress is to consume a diet that is rich in antioxidant nutrients. The second of these circumstances is ongoing (chronic) and undesirable low-level inflammation. Undesirable and chronic inflammation can result from a variety of factors, including unbalanced metabolism, unbalanced lifestyle, unwanted exposure to environmental contaminants, and other factors. One of the best ways to help avoid chronic and unwanted inflammation is to consume a diet that is rich in anti-inflammatory nutrients. Any food that is rich in antioxidant and anti-inflammatory nutrients is a natural candidate for lowering our risk of heart problems, because it contains the exactly right combination of nutrients to lower our risk of oxidative stress and chronic, unwanted inflammation. Many foods contain valuable amounts of antioxidants and anti-inflammatory compounds, but few foods are as rich in these compounds as extra virgin olive oil, and this fact alone accounts for many of the research-based benefits of this culinary oil for health of our cardiovascular system.

In terms of antioxidant protection for our blood vessels, olive oil has been shown to lower risk of lipid peroxidation (oxygen damage to fat) in our bloodstream. Many of the fat-containing molecules in our blood—including molecules like LDL—need to be protected from oxygen damage. Oxygen damage to molecules like LDL significantly increases our risk of numerous cardiovascular diseases, including atherosclerosis. Protection of the LDL molecules in our blood from oxygen damage is a major benefit provided by olive oil and its polyphenols. Equally important is protection against oxygen damage to the cells that line our blood vessels. Once again, it's the polyphenols in olive oil that have been shown to provide us with that protection.

One process we don't want to see in our blood vessels is too much clumping together of blood cells called platelets. While we want to see blood platelets clump together under circumstances like an open wound, where their clumping together acts to seal off the wound, we don't want this process to occur in an ongoing way when there is no acute emergency. Several of the polyphenols found in olive oil—including hydroxytyrosol, oleuropein and luteolin—appear to be especially helpful in keeping our blood platelets in check and avoiding problems of too much clumping (called platelet aggregation). There are also two messaging molecules (called plasminogen activator inhibitor-1 and factor VII) that are capable of triggering too much clumping together of the platelets, and the polyphenols in olive oil can help stop overproduction of these molecules.

Olive oil is one of the few widely used culinary oils that contains about 75% of its fat in the form of oleic acid (a monounsaturated, omega-9 fatty acid). Research has long been clear about the benefits of oleic acid for proper balance of total cholesterol, LDL cholesterol, and HDL cholesterol in the body. When diets low in monounsaturated are made high in monounsaturated fat (by replacing other oils with olive oil), research study participants tend to experience a significant decrease in their total blood cholesterol, LDL cholesterol, and LDL:HDL ratio. Those are exactly the results we want for heart health. In addition to these cholesterol-balancing effects of olive oil and its high oleic acid content, however, comes a new twist: recent research studies have shown that olive oil and its oleic acid may be important factors for lowering blood pressure. Researchers believe that the plentiful amount of oleic acid in olive oil gets absorbed into the body, finds its way into cell membranes, changes signaling patterns at a cell membrane level (specifically, altering G-protein associated cascades) and thereby lowers blood pressure.

Interestingly, a recent laboratory animal study adds one note of caution for anyone wanting to bring the unique cardiovascular benefits of olive oil into their diet. This study found that cardiovascular benefits from olive oil and its polyphenols were not realized when the laboratory animals consumed too many calories and too much total food. This result suggests that olive oil—outstanding as it is in polyphenol protection of our cardiovascular system—needs to be integrated into an overall healthy diet in order to provide its expected benefits.

Digestive Health Benefits

Benefits of olive oil for the digestive tract were first uncovered in research on diet and cancers of the digestive tract. Numerous studies found lower rates of digestive tract cancers—especially cancers of the upper digestive tract, including the stomach and small intestine—in populations that regularly consumed olive oil. Studies on the Mediterranean Diet were an important part of this initial research on olive oil and the digestive tract. Protection of the lower digestive tract (for example, protection of the colon from colon cancer) is less well-documented in the olive oil research, even though there is some strongly supportive evidence from select laboratory animal studies. Many of these anti-cancer effects in the digestive tract were believed to depend on the polyphenols in olive oil and their antioxidant plus anti-inflammatory properties. One particular category of polyphenols, called secoiridoids, continues to be a focus in research on prevention of digestive tract cancers.

Recent research has provided us with even more information, however, about olive oil, its polyphenols, and protection of the digestive tract. One fascinating area of recent research has involved the polyphenols in olive oil and the balance of bacteria in our digestive tract. Numerous polyphenols in olive oil have been shown to slow the growth of unwanted bacteria, including bacteria commonly responsible for digestive tract infections. These polyphenols include oleuropein, hydroxytyrosol, and tyrosol. Some of these same polyphenols—along with other olive oil polyphenols like ligstroside—are specifically able to inhibit the growth of the Helicobacter pylori bacterium. This effect of the olive oil polyphenols may be especially important, since overpopulation of Helicobacter bacteria coupled with over-attachment of Helicobacter to the stomach lining can lead to stomach ulcer and other unwanted digestive problems.

Bone Health Benefits

Support of overall bone health is another promising area of olive oil research. While most of the initial study in this area has been conducted on laboratory animals, better blood levels of calcium have been repeatedly associated with olive oil intake. In addition, at least two polyphenols in olive oil—tyrosol and hydroxytyrosol—have been shown to increase bone formation in rats. A recent group of researchers has also suggested that olive oil may eventually prove to have special bone benefits for post-menopausal women, since they found improved blood markers of overall bone health in female rats who had been fed olive oil after having their ovaries removed. Taken as a group, the above studies suggest that bone health benefits may eventually be viewed as an important aspect of olive oil intake.

Cognitive Benefits

Improved cognitive function—especially among older adults—is a well-known feature of the Mediterranean Diet. As the staple oil in that diet, olive oil has been of special interest for researchers interested in diet and cognitive function. In France, a recent study large-scale study on older adults has shown that visual memory and verbal fluency can be improved with what the researchers called "intensive use" of olive oil. In this case, "intensive use" meant regular use of olive oil not just for cooking, or as an ingredient in sauces and dressings, but in all of these circumstances.

Equally fascinating to us in the area of cognition has been recent research on olive oil intake and brain function. In laboratory animals with brain function that had been compromised by lack of oxygen, consumption of olive oil helped offset many different types of brain-related problems, including unbalanced water content, unbalanced nervous system activity, and too easy passage of molecules across the blood brain barrier. This animal research has given scientists many further clues about the ways in which olive oil might provide us with cognitive benefits. The ability to help protect our brain during times of imbalance may turn out to be one of the special health benefits offered by this unique culinary oil.

Anti-Cancer Benefits

The polyphenols found in olive oil are a natural for helping us lower our risk of certain cancer types. Many types of cancer only get initiated when cells are overwhelmed by oxidative stress (damage to cell structure and function by overly reactive oxygen-containing molecules) and by chronic excessive inflammation. Since the polyphenols in olive oil act both as antioxidants and anti-inflammatory molecules, they are perfectly suited for lowering our cells' risk of oxidative stress and chronic unwanted inflammation. Research studies have shown that as little as 1-2 tablespoons of olive oil per day can lower our risk of certain cancer types, including cancers of the breast, respiratory tract, upper digestive tract, and to a lesser extent, lower digestive tract (colorectal cancers). In some research studies, the anti-cancer benefits of olive oil do not show up until the diets of routine olive oil users are compared with the diets of individuals who seldom use olive oil and who instead consume added fats that are more saturated in composition (for example, butter).

While most of the anti-cancer research on olive oil has focused on its polyphenols and their antioxidant and anti-inflammatory properties, several studies have uncovered other fascinating ways in which olive oil provides its anti-cancer benefits. These other ways include the improvement of cell membrane function in a way that lowers risk of cancer development and the altering gene expression in cells in a way that enhances their antioxidant defense system. A final important mechanism linking olive oil intake to decreased cancer risk involves protection of our DNA. The antioxidants in olive oil appear to have a special ability to protect DNA (deoxyribonucleic acids)—the key chemical component of genetic material in our cells—from oxygen damage. DNA protection from unwanted oxidative stress means better cell function in wide variety of ways and provides a cell with decreased risk of cancer development.

There is also encouraging research on the potential for olive oil to help with control of certain cancers once they have already developed. For example, improvement of breast cancer status has been an area of particular interest in olive oil research. Here some of the research has focused on the secoiridoids in olive oil (especially oleocanthal), and its ability to help keep breast cancer cells from reproducing. Another example involves the ability of hydroxytyrosol (HT) in olive oil to trigger programmed cell death (apoptosis) in colon cancer cells. HT may be able to accomplish this anti-cancer effect by helping block the enzymatic activity of fatty acid synthetase (FAS). These cancer-controlling properties of olive oil and olive oil constituents are generally referred to as the "antiproliferative" properties of olive oil. We expect to see more future research in this area.

Description

Olive oil is made from the crushing and then subsequent pressing of olives. The fact that olives are rich in oil is reflected in the botanical name of the olive tree—Olea europea—since the word "oleum" means oil in Latin. Olive oil is available in a variety of grades, which reflect the degree to which it has been processed. Extra virgin olive oil is derived from the first pressing of the olives and has the most delicate flavor and strongest overall health benefits. See How to Select and Store for more information on these different grades of olive oil.

History

Olives, one of the oldest foods known, are thought to have originated in Crete or Syria between five and seven thousand years ago. Since ancient times, the olive tree has provided food, fuel, timber and medicine for many civilizations, and has been regarded as a symbol of peace and wisdom. The venerable oil of the olive has been consumed since as early as 3,000 B.C.

It's not clear exactly how olive trees arrived in the U.S., but it's clear that the time frame was much later, during the 1500-1700's. Spanish colonizers of North America definitely brought olive trees across the Atlantic Ocean during the 1500-1700's, and while some may have been brought directly to the region which is now California, olive trees may also have been brought to the region from Mexico, where cultivation by the Spanish was already underway.

Olive oil has been and still is a staple in the diet of many Mediterranean countries. The recent discovery that the Mediterranean diet, which features this prized oil, may be linked to a reduced risk of heart disease and other health conditions has caused olive oil to become very popular in the United States in the past few decades. Today, much of the commercial cultivation of olive oil is still centered in the Mediterranean region in such countries as Spain (36% of total production), Italy (25%), and Greece (18%). These countries—along with the remaining European countries—also consume about two-thirds of all olive oil that is produced. Regions of the world with quickly-increasing consumption and production of olive oil include South America (especially Chile) and Australia.

How to Select and Store

Since olive oil can become rancid from exposure to light and heat, there are some important purchasing criteria you should follow to ensure buying a better quality product. Look for olive oils that are sold in dark tinted bottles since the packaging will help protect the oil from oxidation caused by exposure to light. In addition, make sure the oil is displayed in a cool area, away from any direct or indirect contact with heat.

When you shop for olive oil, you will notice a host of different grades are available, including extra-virgin, virgin, refined and pure:

• Extra virgin olive oil (EVOO) is the unrefined oil derived from the first pressing of the olives and has the most delicate flavor
• Virgin olive oil is also derived from the first pressing of the olives but has a higher acidity level than extra virgin olive oil (as well as lower phytonutrient levels and a less delicate taste). According to the standards adopted by the International Olive Council (IOC), "virgin" can contain up to 2% free acidity (expressed as oleic acid), while "extra virgin" can only contain up to 0.8% of free acidity.

  It is important to note, however, that acidity is by no means the only difference between EVOO and other grades of olive oil. In fact, a sizeable amount of controversy has arisen within the olive oil industry over key characteristics of EVOO and the extent to which these characteristics are present in commercial products. Since over 90% of all EVOO consumed in the United States is imported, many evaluators of EVOO have looked to the International Olive Council (IOC) headquartered in Madrid, Spain for quality criteria in evaluating EVOO. However, unlike Italy, Spain, Greece, Portugal, and other European Union countries that were founding members of the IOC, the United States has never become an official IOC member country or adopted IOC standards for EVOO as its own mandatory standards.

  In the United States, voluntary standards for olive oil have traditionally been set by the U.S. Department of Agriculture (USDA), which in 2010 did update its own standards to more closely resemble IOC standards in terms of EVOO chemistry. However, even though most IOC chemical standards like percent free acidity were adopted by the USDA, some differences remain between IOC and USDA chemical criteria. (In addition, since 2010, the IOC has gone on to update and revise some of its chemical standards, and these changes are not reflected in the existing USDA criteria.) But a perhaps even bigger part of the controversy over EVOO standards has not involved chemical criteria like percent free acidity but rather sensory criteria (also called "organoleptic" criteria) like taste and aroma. If you consider olive oil as falling into the category of a fresh fruit juice (in the sense that an olives actually belong to a special group of fruits called "drupes" and can be pressed to obtain their oil or "juice"), aroma and taste might be considered as defining characteristics of this food. Assurance of excellent taste and aroma is a more difficult regulatory standard than assurance of a chemical standard like percent free acidity, and to some extent may require closer monitoring of local conditions and plant varieties. In this context, several organizations in the U.S. offer their own quality seal for EVOO, including the California Olive Oil Council (COOC) and the North American Olive Oil Association (NAOOA). Quality seals from these organizations can help provide assurance about EVOO quality.

  Similar organizations exist in Europe and can be helpful for assuring EVOO quality. In most cases, your best bet is to look for specific initials on the olive oil container that represent official review and sanctioning by these organizations. Among your options here are the designations "A.O.C." or "D.O.P." or "D.P.O." or "D.O." "A.O.C." stands for the French term "Appellation D'origine Controlée." "D.O.P." stands for the Italian "Denominazione d'Origine Protetta" (note that D.O.P. is also written as "D.P.O." in some other European countries). In Spain, a similar designation is "D.O." which stands for "Denominacion de Origen." Any of these initials can help provide assurance of quality with respect to extra virgin olive oils.

• "Pure olive oil" is a phrase that is somewhat confusing, and perhaps also somewhat misleading. If you see the term "pure" on the label of an olive oil container, it typically means that the oil is a blend of refined and unrefined virgin olive oils. "Refined olive oil" is obtained from unrefined virgin olive oils, and it's only allowed to contain up to 0.3% of free acidity. However, while lower in free acidity than extra virgin or virgin olive oils, refined olive oil loses some of its unique nutrient content through the refining process. For this reason, we recommend the purchase of extra virgin olive oil over all other olive oil types, including "pure olive oil."

Another term that you may see on a bottle of olive oil is "cold pressed." This term means that very minimal heating (and by IOC standards, under 81F/27C) was used when mechanically processing the olives to obtain their oil. We like the idea of cold pressed extra virgin olive oil, because we believe that minimal use of heating, combined with the phytonutrient-rich first pressing of the oil, provides the strongest possible nutrient composition from an extracted oil.

Proper storage techniques for olive oil are very important, not only to preserve the delicate taste of the oil, but also to ensure that it does not spoil and become rancid, which will have a negative effect on its nutritional profile.

Even though olive oil's monounsaturated fats are more stable and heat-resistant than the polyunsaturated fats that predominate in other oils (especially the easily damaged omega-3 fatty acids found in flax seed oil, which should always be refrigerated and never heated), olive oil should be stored properly and used within 1-2 months to ensure its healthy phytonutrients remain intact and available. Research studies have shown compromise in the nutritional quality of olive oil after two months' period of time, even when the oil was properly stored.

Proper storage of olive oil includes protection from light. There is debate about the ideal type of storage container. Tinted glass bottles are one of the best storage options for preventing unwanted contamination of the olive oil with packaging materials (as might occur, for example, with the use of dark plastic bottles in which very small amounts of plastic might migrate from the bottle into the oil). However, depending upon the degree and type of glass tinting, exposure to all light might not be prevented with the use of tinted glass. Metal containers for olive oil storage are also an option, although it is unclear about the potential for olive oil to be affected by the metal elements in the container. The transfer of olive oil to a sealed ceramic container is also an option. If you decide to purchase olive oil in a tinted glass bottle, we recommend that you store it in a lightproof area, like a cabinet with solid doors or closed pantry. If you decide to purchase in either plastic or metal containers, you may want to take the additional step of moving the oil into a ceramic container that can be sealed. If you aren't sure how quickly you will be using your olive oil, you may want to buy it in small-size amounts to avoid the problems that can arise with longer-term storage.

Purchase only as much as you will use in one to two months and store away from light and heat. Protect your olive oil's flavor and antioxidants by transferring 7 to 10 days' worth of oil to a smaller bottle to lessen the oxidation that occurs when the oil is exposed to air. Leave this small bottle at room temperature for easy use, but refrigerate the rest. When chilled, olive oil will solidify slightly and turn cloudy, but once restored to room temperature, it will regain its normal appearance, and its quality will be better maintained. Although it may be convenient, definitely don't store your olive oil near the stove as the heat will damage it.

While we haven't seen research that discusses declines in carotenoids and vitamin E for extra virgin olive oil, we have seen it for virgin oil. While this is not the type of oil we recommend, we still thought to include this interesting information here:

Research conducted at the University of Lleida in Spain and reported in the Journal of Agriculture and Food Chemistry found that levels of chlorophyll, carotenoids and antioxidant phenols dropped dramatically after virgin olive oil had been in storage 12 months-even under the best controlled conditions.

Chlorophyll content dropped by as much as 30%; beta-carotene by 40%, and vitamin E (alpha-tocopherol) by 100%!

Phenols, which are not only the main antioxidants in virgin olive oil, but are also responsible for its distinctive rich flavor, also dropped precipitously after 12 months storage.

Research published in New Scientist magazine has confirmed that light destroys many of the antioxidants in olive oil. Researchers at the University of Bari, in southern Italy, compared oils stored in the light or in the dark for 12 months. Oils stored in clear bottles under supermarket lighting lost at least 30% of their tocopherols (vitamin E) and carotenoids.

After just two months' exposure to light, peroxide (free radical) levels had increased so much that the olive oil could no longer be classified as extra virgin.

Tips for Preparing and Cooking

Tips on Preparing Extra Virgin Olive Oil

We suggest using extra virgin olive oil in dressing salads and a variety of cooked foods. We don't recommend cooking with extra virgin olive oil (see below). One of our favorite recipes featuring extra virgin olive oil, which can be used on both salads and cooked vegetables, is our Mediterranean Dressing:

• 3-5 TBS extra virgin olive oil
• 1 TBS fresh lemon juice
• 1 clove garlic chopped
• Salt and pepper to taste

The Healthiest Way of Cooking Extra Virgin Olive Oil: A Word About Heating

Different manufacturers list different smoke points for their olive oils, and some manufacturers list a temperature very close to smoke point as their maximum limit for safe heating of the oil. While these temperatures might be correct for avoiding large amounts of some harmful substances that can be created through heating of the oil above smoke point, they are not correct limits for preserving the maximum amount of nutrients (especially phytonutrients like oleuropein and oleocanthal) found in high-quality, extra virgin olive oil. Studies show a loss of these phytonutrients in the range of 5-15%, even when extra virgin olive oil is used in cooking at temperatures below smoke point. For these reasons, we don't recommend cooking with extra virgin olive oil. For more details, see Is it OK to cook with extra-virgin olive oil? and George's video "Why I Don't Cook with Extra Virgin Olive Oil".

Research studies on the heating of olive oil are fairly extensive, and some of the issues involved with olive oil heating are difficult to summarize in a single paragraph. For this reason, we've created a special article on our website entitled, " Is it OK to cook with extra-virgin olive oil?"

How to Enjoy

A Few Quick Serving Ideas

• Use extra virgin olive oil in your salad dressings.
• Puree minced garlic, cooked potatoes and extra virgin olive oil together to make exceptionally delicious garlic mashed potatoes. Season to taste.
• Drizzle extra virgin olive oil over healthy sautéed vegetables before serving.
• Puree extra virgin olive oil, garlic and your favorite beans together in a food processor. Season to taste and serve as a dip.
• Instead of putting the butter dish out on the table, place a small cup of extra virgin olive oil out instead to use on your bread or rolls. For extra flavor, try adding a little Balsamic vinegar or any of your favorite spices to the extra virgin olive oil.

WHFoods Recipes That Feature Extra Virgin Olive Oil

You'll find that many of our recipes feature extra virgin olive oil. For example, we like to add it to vegetables after they have been lightly cooked, either on its own, or as part of our Mediterranean Dressing.

Individual Concerns

Olive oil is not a commonly allergenic food and is not known to contain measurable amounts of oxalates or purines.

Nutritional Profile

Extra virgin olive oil is a particularly valuable of antioxidant and anti-inflammatory phytonutrients. Among these phytonutrients are many standout polyphenols. These polyphenols include tyrosols (oleuropein, tyrosol, hydroxytyrosol), flavones (apigenin, luteolin), secoiridoids (oleocanthal), anthocyanidins (cyanidins, peonidins), hydroxycinnamic acids (caffeic, cinnamic, ferulic, and coumaric acids), flavonols (quercetin, kaempferol), lignans (pinoresinol), and hydroxybenzoic acids (vanillic and syringic acids). Olive oil is a unique plant oil in terms of its fat composition, containing about three-fourths of its fat in the form of oleic acid (a monounsaturated, omega-9 fat). It is a good source of vitamin E and also provides valuable amounts of the antioxidant beta-caroteneas well as squalene, a much less common antioxidant that also plays a special role in skin health.

For an in-depth nutritional profile click here: Olive oil.

For an in-depth nutritional profile click here: Olive oil.

In-Depth Nutritional Profile

In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Olive oil, extra virgin is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.

Introduction to Food Rating System Chart

In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients. The following chart shows the nutrients for which this food is either an excellent, very good, or good source (below the chart you will find a table that explains these qualifications). If a nutrient is not listed in the chart, it does not necessarily mean that the food doesn't contain it. It simply means that the nutrient is not provided in a sufficient amount or concentration to meet our rating criteria. (To view this food's in-depth nutritional profile that includes values for dozens of nutrients - not just the ones rated as excellent, very good, or good - please use the link below the chart.) To read this chart accurately, you'll need to glance up in the top left corner where you will find the name of the food and the serving size we used to calculate the food's nutrient composition. This serving size will tell you how much of the food you need to eat to obtain the amount of nutrients found in the chart. Now, returning to the chart itself, you can look next to the nutrient name in order to find the nutrient amount it offers, the percent Daily Value (DV%) that this amount represents, the nutrient density that we calculated for this food and nutrient, and the rating we established in our rating system. For most of our nutrient ratings, we adopted the government standards for food labeling that are found in the U.S. Food and Drug Administration's "Reference Values for Nutrition Labeling." Read more background information and details of our rating system.

In-Depth Nutritional Profile for Olive oil, extra virgin

References

• Bermudez B, Lopez S, Ortega A et al. Oleic Acid in olive oil: from a metabolic framework toward a clinical perspective. Curr Pharm Des. 2011;17(8):831-43. 2011.
• Berr C, Portet F, Carriere I et al. Olive Oil and Cognition: Results from the Three-City Study. Dement Geriatr Cogn Disord. 2009 October; 28(4): 357-364. Published online 2009 October 30. doi: 10.1159/000253483. 2009.
• Bondia-Pons I, Schroder H, Covas MI et al. Moderate consumption of olive oil by healthy European men reduces systolic blood pressure in non-Mediterranean participants. J Nutr. 2007 Jan;137(1):84-87. 2007. PMID:17182805. 2007.
• Brinkman MT, Buntinx F, Kellen E et al. Consumption of animal products, olive oil and dietary fat and results from the Belgian case-control study on bladder cancer risk. Eur J Cancer. 2011 Feb;47(3):436-42. Epub 2010 Oct 12. 2010.
• Bullo M, Lamuela-Raventos R and Salas-Salvado J. Mediterranean Diet and Oxidation: Nuts and Olive Oil as Important Sources of Fat and Antioxidants. Curr Top Med Chem. 2011 Apr 21. [Epub ahead of print]. 2011.
• Caponio F, Bilancia MT, Pasqualone A, Sikorska E, Gomes T. Influence of the exposure to light on extra virgin olive oil quality during storage. European Food Research and Technology, 2005 July; 221(1-2):92-98. 2005.
• Casal S, Malheiro R, Sendas A et al. Olive oil stability under deep-frying conditions. Food Chem Toxicol. 2010 Oct;48(10):2972-9. Epub 2010 Aug 3. 2010.
• Castaner O, Fito M, Lopez-Sabater MC et al. The effect of olive oil polyphenols on antibodies against oxidized LDL. A randomized clinical trial. Clin Nutr. 2011 Mar 2. [Epub ahead of print]. 2011.
• Cicerale S, Lucas L and Keast R. Biological Activities of Phenolic Compounds Present in Virgin Olive Oil. Int J Mol Sci. 2010; 11(2): 458-479. Published online 2010 February 2. doi: 10.3390/ijms11020458. 2010.
• Corona G, Spencer JPE and Dessi MA. Extra virgin olive oil phenolics: absorption, metabolism, and biological activities in the GI tract. Toxicology and Industrial Health, May 2009; 25: 285 - 293. 2009.
• Covas MI, de la Torre K, Farre-Albaladejo M et al. Postprandial LDL phenolic content and LDL oxidation are modulated by olive oil phenolic compounds in humans. Free Radic Biol Med. 2006 Feb 15;40(4):608-16. Epub 2005 Oct 18. 2006. PMID:16458191. 2006.
• Covas MI, Nyyssonen K, Poulsen HE, Kaikkonen J, Zunft HJ, Kiesewetter H, Gaddi A, de la Torre R, Mursu J, Baumler H, Nascetti S, Salonen JT, Fito M, Virtanen J, Marrugat J. EUROLIVE Study Group. The effect of polyphenols in olive oil on heart disease risk factors: a randomized trial. Ann Intern Med. 2006 Sep 5;145(5):333-41. 2006. PMID:16954359.
• D'Imperio M, Gobbino M, Picanza A et al. Influence of Harvest Method and Period on Olive Oil Composition: an NMR and Statistical Study. J Agric Food Chem. 2010 Oct 5. [Epub ahead of print]. 2010.
• Daccache A, Lion C, Sibille N et al. Oleuropein and derivatives from olives as Tau aggregation inhibitors. Neurochem Int. 2011 May;58(6):700-7. Epub 2011 Feb 17. 2011.
• Damasceno NR, Perez-Heras A, Serra M et al. Crossover study of diets enriched with virgin olive oil, walnuts or almonds. Effects on lipids and other cardiovascular risk markers. Nutr Metab Cardiovasc Dis. 2011 Mar 21. [Epub ahead of print]. 2011.
• de la Lastra Romero CA and Gonz´lez G. An up-date of olive oil and bioactive constituents in health: molecular mechanisms and clinical implications. Curr Pharm Des. 2011;17(8):752-3. 2011.
• de Roos B, Zhang X, Rodriguez Gutierrez G et al. Anti-platelet effects of olive oil extract: in vitro functional and proteomic studies. Eur J Nutr. 2011 Jan 1. [Epub ahead of print]. 2011.
• Delgado-Lista J, Garcia-Rios A, Perez-Martinez P et al. Olive oil and haemostasis: platelet function, thrombogenesis and fibrinolysis. Curr Pharm Des. 2011;17(8):778-85. 2011.
• Ebaid GM, Seiva FR, Rocha KK et al. Effects of olive oil and its minor phenolic constituents on obesity-induced cardiac metabolic changes. Nutr J. 2010 Oct 19;9:46. 2010.
• Eilertsen KE, Maehre HK, Cludts K et al. Dietary enrichment of apolipoprotein E-deficient mice with extra virgin olive oil in combination with seal oil inhibits atherogenesis. Lipids Health Dis. 2011 Mar 3;10:41. 2011.
• Elnagar AY, Sylvester PW, and El Sayed KA. (-)-Oleocanthal as a c-Met Inhibitor for the Control of Metastatic Breast and Prostate Cancers. Planta Med. 2011 Feb 15. [Epub ahead of print]. 2011.
• Escrich E, Solanas M, Moral R et al. Modulatory effects and molecular mechanisms of olive oil and other dietary lipids in breast cancer. Curr Pharm Des. 2011;17(8):813-30. 2011.
• Frankel EN. Nutritional and biological properties of extra virgin olive oil. J Agric Food Chem. 2011 Feb 9;59(3):785-92. Epub 2011 Jan 6. 2011.
• Garcia-Segovia P, Sanchez-Villegas A, Doreste J et al. Olive oil consumption and risk of breast cancer in the Canary Islands: a population-based case-control study. Public Health Nutr 2006 Feb;9(1A):163-7. 2006. PMID:16512965. 2006.
• Hashim YZ, Eng M, Gill C et al. Components of olive oil and chemoprevention of colorectal cancer. Nutr Rev. 2005 Nov;63(11):374-86. 2005. PMID:16370222. 2005.
• Impellizzeri D, Esposito E, Mazzon E et al. The effects of oleuropein aglycone, an olive oil compound, in a mouse model of carrageenan-induced pleurisy. Clin Nutr. 2011 Mar 14. [Epub ahead of print]. 2011.
• Kontogianni MD, Panagiotakos DB, Chrysohoou C, Pitsavos C, Zampelas A, Stefanadis C. The impact of olive oil consumption pattern on the risk of acute coronary syndromes: The CARDIO2000 case-control study. Clin Cardiol. 2007 Mar;30(3):125-9. 2007. PMID:17385704.
• Lucas L, Russell A and Keast R. Molecular mechanisms of inflammation. Anti-inflammatory benefits of virgin olive oil and the phenolic compound oleocanthal. Curr Pharm Des. 2011;17(8):754-68. 2011.
• Machowetz A, Poulsen HE, Gruendel S et al. Effect of olive oils on biomarkers of oxidative DNA stress in Northern and Southern Europeans. FASEB J. 2007 Jan;21(1):45-52. Epub 2006 Nov 16. 2007. PMID:17110467. 2007.
• Marí-Sanchis A, Beunza JJ, Bes-Rastrollo M et al. [Olive oil consumption and incidence of diabetes mellitus, in the Spanish sun cohort.] . Nutr Hosp. 2011 Feb;26(1):137-143. Spanish. 2011.
• Martinez Nieto L, Hodaifa G and Lozano Peña JL. Changes in phenolic compounds and Rancimat stability of olive oils from varieties of olives at different stages of ripeness. J Sci Food Agric. 2010 Nov;90(14):2393-8. 2010.
• Mascitelli L and Goldstein MR. Olive oil, iron, and cardiovascular disease prevention. 2011 Apr;68(4):391; author reply 391-2. Epub 2011 Feb 16. No abstract available. 2011.
• Mascitelli L, Pezzetta F and Goldstein MR. Is the beneficial antioxidant effect of olive oil mediated by interaction of its phenolic constituents and iron? . Arch Med Res. 2010 May;41(4):295-6. 2010.
• Menendez JA, Vazquez-Martin A, Colomer R et al. Olive oil's bitter principle reverses acquired autoresistance to trastuzumab (Herceptin) in HER2-overexpressing breast cancer cells. BMC Cancer. 2007; 7: 80. Published online 2007 May 9. doi: 10.1186/1471-2407-7-80. 2007.
• Mohagheghi F, Bigdeli MR, Rasoulian B et al. Dietary virgin olive oil reduces blood brain barrier permeability, brain edema, and brain injury in rats subjected to ischemia-reperfusion. ScientificWorldJournal. 2010 Jun 29;10:1180-91. 2010.
• Morello JR, Motilva MJ, Tovar MJ, Romero MP. Changes in commercial virgin olive oil (cv Arbequina) during storage, with special emphasis on the phenolic fraction. J Agric Food Chem, 2004 May; 85(3):357-364. 2004.
• Moreno DA, López-Berenguer C, García-Viguera C. Effects of stir-fry cooking with different edible oils on the phytochemical composition of broccoli. J Food Sci. 2007 Jan;72(1):S064-8. 2007. PMID:17995900.
• Mosher A. Justification for additional data analysis: fruit, vegetables, and olive oil and risk of coronary heart disease in Italian women: the EPICOR Study. Am J Clin Nutr. 2011 Apr 13. [Epub ahead of print] . 2011.
• Notarnicola M, Tutino V, Bocale D et al. Effects of olive oil polyphenols on fatty acid synthase gene expression and activity in human colorectal cancer cells. Genes Nutr. 2011 February; 6(1): 63-69. Published online 2010 May 16. doi: 10.1007/s12263-010-0177-7. 2011.
• Oliveras-Ferraros C, Fernandez-Arroyo S, Vazquez-Martin A et al. Crude phenolic extracts from extra virgin olive oil circumvent de novo breast cancer resistance to HER1/HER2-targeting drugs by inducing GADD45-sensed cellular stress, G2/M arrest and hyperacetylation. Int J Oncol. 2011 Jun;38(6):1533-47. doi: 10.3892/ijo.2011.993. Epub 2011 Mar 30. 2011.
• Papageorgiou N, Tousoulis D, Psaltopoulou T et al. Divergent anti-inflammatory effects of different oil acute consumption on healthy individuals. Eur J Clin Nutr. 2011 Apr;65(4):514-9. Epub 2011 Feb 16. 2011.
• Pelucchi C, Bosetti C, Negri E et al. Olive Oil and Cancer Risk: An Update of Epidemiological Findings through 2010. Curr Pharm Des. 2011;17(8):805-12. 2011.
• Peyrot des Gachons C, Uchida K, Bryant B et al. Unusual pungency from extra-virgin olive oil is attributable to restricted spatial expression of the receptor of oleocanthal. J Neurosci. 2011 Jan 19;31(3):999-1009. 2011.
• Pinto J, Paiva-Martins F, Corona G et al. Absorption and metabolism of olive oil secoiridoids in the small intestine. Br J Nutr. 2011 Mar 17:1-12. [Epub ahead of print]. 2011.
• Romero C, Medina E, Vargas J, Brenes M, Castro AD. In Vitro Activity of Olive Oil Polyphenols against Helicobacter pylori. J Agric Food Chem. 2007 Feb 7;55(3):680-6. 2007. PMID:17263460.
• Ruano J, Lopez-Miranda J, Ruano J et al. Intake of phenol-rich virgin olive oil improves the postprandial prothrombotic profile in hypercholesterolemic patients. Am J Clin Nutr, Aug 2007; 86: 341 - 346. 2007.
• Ruiz-Canela M and Martinez-Gonzalez MA. Olive oil in the primary prevention of cardiovascular disease. Maturitas. 2011 Mar;68(3):245-50. Epub 2011 Jan 8. 2011.
• Saleh NK and Saleh HA. Olive Oil effectively mitigates ovariectomy-induced osteoporosis in rats. BMC Complement Altern Med. 2011 Feb 4;11:10. 2011.
• Salvini S, Sera F, Caruso D, Giovannelli L, Visioli F, Saieva C, Masala G, Ceroti M, Giovacchini V, Pitozzi V, Galli C, Romani A, Mulinacci N, Bortolomeazzi R, Dolara P, Palli D. Daily consumption of a high-phenol extra-virgin olive oil reduces oxidative DNA damage in postmenopausal women. Br J Nutr. 2006 Apr;95(4):742-51. 2006. PMID:16571154.
• Sanchez-Hernandez L, Castro-Puyana M, Luisa Marina M et al. Determination of betaines in vegetable oils by capillary electrophoresis tandem mass spectrometry - application to the detection of olive oil adulteration with seed oils. Electrophoresis. 2011 Jun;32(11):1394-401. doi: 10.1002/elps.201100005. Epub 2011 Apr 26. 2011.
• St-Onge MP and Bosarge A. Weight-loss diet that includes consumption of medium-chain triacylglycerol oil leads to a greater rate of weight and fat mass loss than does olive oil. The American Journal of Clinical Nutrition, Volume 87, Number 3 (March 2008), pp. 621-626. 2008.
• Terés S, Barcelo-Coblijn G, Benet M et al. Oleic acid content is responsible for the reduction in blood pressure induced by olive oil. Proc Natl Acad Sci U S A. 2008 September 16; 105(37): 13811-13816. Published online 2008 September 4. doi: 10.1073/pnas.0807500105. 2008.
• Vichi S, Romero A, Tous J et al. The Activity of Healthy Olive Microbiota during Virgin Olive Oil Extraction Influences Oil Chemical Composition. J Agric Food Chem. 2011 May 11;59(9):4705-4714. Epub 2011 Apr 20. 2011.
• Visioli F and Bernardini E. Extra Virgin Olive Oil's Polyphenols: Biological Activities. Curr Pharm Des. 2011;17(8):786-804. 2011.
• Zrelli H, Matsuoka M, Kitazaki S et al. Hydroxytyrosol Induces Proliferation and Cytoprotection against Oxidative Injury in Vascular Endothelial Cells: Role of Nrf2 Activation and HO-1 Induction. J Agric Food Chem. 2011 May 11;59(9):4473-82. Epub 2011 Apr 13. 2011.

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