The humble olive is not just a dietary staple in the Mediterranean region — it also enjoys the reputation of being a healthy oil in the United States. It is valued not only for its flavor, but also for its range of wellness benefits. Learn more about this plant-based oil, its uses (why you should drizzle it cold on salads, not cook with it), health value and how to distinguish good olive oil from bad ones.
What Is Olive Oil?
Olive oil is pressed from fresh olives and is made mainly in the Mediterranean, mostly in Italy, Spain and Greece. It is available all year-round. Just like in wine-making, several factors affect the character of the oil, including climate, soil and the way the olives are harvested and pressed.1
The flavor, smell and color of olive oil can vary significantly, based on its origin and whether it is extra-virgin (finest grade) or not. Generally, the hotter the country, the more robust the oil's flavor will be.2
The U.S. Department of Agriculture (USDA) grades olive oil based on flavor, odor, absence of defects and acidity. Extra-virgin olive oil is described as having an excellent flavor and odor, and a free fatty acid content of ≤ 0.8 grams per 100 grams (0.8 percent).3 Commonly sold varieties of olive oil include:
- Extra virgin olive oil: The highest-quality olive oil you can get. It is unrefined and contains more nutrients compared to other processed varieties.4
- Pure olive oil:5 Made by combining extra-virgin olive oil and refined olive oil, resulting in a lower-quality product.6 It is sometimes sold as “refined olive oil.”7
- Light olive oil: The word “light” is a marketing term that simply refers to the oil’s lighter flavor. In truth, light olive oil is simply refined olive oil that has a neutral taste and a higher smoke point.8
- Olive-pomace oil: This version of olive oil is made from leftover olive pulps, and the remaining liquid is extracted using chemical solvents. Avoid this type of olive oil at all costs.9
Other Practical Uses of Olive Oil
Olive oil can be flavored with herbs and spices, which you can steep in the oil for 10 days or so. If you’re using chili, you need far less time.
However, it’s important to note that olive oil is not recommended for cooking — it should only be used cold, usually drizzled on salads and other foods. Extra-virgin olive oil’s chemical structure and its large amount of unsaturated fats make it very susceptible to oxidative damage when used for cooking.10 Whenever you need an oil to cook with, use coconut oil or grass fed butter.
Good Housekeeping lists several practical uses of olive oil. It can be used to moisturize your skin, as well as remove eye makeup and paint from hair.11 According to Michael Bertoldo, a stylist from California, olive oil can also be used as a safe, natural lubricant for a close shave and as a soothing aftershave.12
Chemical Composition of Olive Oil
Ninety-nine percent of olive oil is made up of triacylglycerols, also known as triglycerides.13 Other compounds include fatty acids, such as:14
Mono- and diacylglycerols, hydrocarbons, sterols, as well as phenolic and volatile compounds make up olive oil.15
Potential Benefits of Olive Oil
If used properly, olive oil may be one of the healthiest oils you can add to your diet. Research has shown that it may help with a number of functions, such as:
Managing Type 2 diabetes: Researchers found that the fatty acids helped manage and lower the risk of Type 2 diabetes. In addition, higher olive intake lowered the risk of developing Type 2 diabetes by 16 percent.16
Managing inflammation: Olive oil is rich in oleic acid, a type of monounsaturated fat. Studies have shown that oleic acid is linked to reduced biomarkers of inflammation17 such as C-reactive protein.18
Boosting antioxidant profile: Several studies note that olive oil contains a high number of antioxidants, such as phenolic compounds, that may help remove free radicals throughout your body.19,20,21
Improving heart health: Numerous studies indicate that consuming olive oil can benefit your cardiovascular system in many ways, such as lowering LDL cholesterol levels,22 boosting endothelial function,23 decreasing blood pressure,24 reducing platelet aggregation25 and lowering the risk of thrombosis.26
Reducing risk of Alzheimer’s disease: In a mice study, olive oil exhibited potential neuroprotective properties against Alzheimer’s disease.27 In another study, this time done on humans, researchers stated that the Mediterranean diet (supplemented with olive oil) helped improve cognition compared to a low-fat diet.28
Lowering the risk of cancer: In a study published in the Annals of Oncology, oleic acid helped inhibit the growth of breast cancer cells.29
How to Make Olive Oil
The craft of making olive oil has been mastered in the Mediterranean region over thousands of years now. Each grower can have a unique way of tending the trees and producing the oil. The trees are matured for several years before they produce olives.30
After being picked, the olives are washed and the leaves, twigs and stems are removed. Afterward, the olives are processed to extract the water and oil, which are then separated. The olive oil is stored in stainless steel containers at about 65 degrees Fahrenheit to prevent breakdown before bottling and shipping.
Extracting oil from olives is better reserved for expert growers and producers, but you can immediately enjoy high-quality olive oil in your salads and other no-cook recipes. Here is one recipe from NutritionAction.com31 you can try.
Herbed Chicken Salad Recipe
- 1/4 cup flat-leaf parsley leaves
- 1/4 cup basil leaves
- 1/2 cup fresh dill sprigs
- 2 oil-packed anchovies, drained
- 1 small garlic clove
- 1/3 cup homemade mayonnaise (made from olive oil and egg)
- 1/3 cup raw sour cream
- 2 tablespoons lemon juice
- Freshly ground black pepper
- 1 pound cooked organic, free-range chicken, shredded
- 2 jarred roasted red peppers, well-drained and chopped (or substitute fresh roasted peppers)
- 3 inner celery ribs with leaves, thinly sliced
- 8 cups mixed salad greens
- 1/2 pound tomatoes, chopped
- Make the herbed mayonnaise: In a food processor, pulse the herbs, anchovies and garlic until coarsely chopped. Add the mayonnaise, sour cream and lemon juice and process until smooth. Season to taste with pepper.
- In a large bowl, toss the herbed mayonnaise with the chicken, peppers and celery. Serve on the salad greens and garnish with the tomatoes.
How Does Olive Oil Work?
The benefits of olive oil come from its biologically active compounds. According to Alternative Medicine Review, the key active compounds found in olive oil include oleic acid, phenolic constituents and squalene. Furthermore, the main phenolic chemicals found in olive oil include hydroxytyrosol, tyrosol and oleuropein, all of which demonstrate antioxidant properties.32
How to Identify High-Quality Olive Oil
As previously mentioned, olive oil is ideal as a salad dressing and should not be used for cooking, as it can be easily damaged by heat. But it doesn’t end there. You also need to learn how to determine whether the olive oil you’re about to use is still fresh. Here are four signs of defective olive oil, as reported by Olive Oil Times:33
• Rancidity: Remember that rancid olive oil smells like crayons, tastes like rancid nuts and has a greasy mouth feel. So beware of leaving your bottle of olive oil right on the counter, opening and closing it multiple times in a week. Any time it is exposed to air and/or light, it oxidizes. The chlorophyll in extra virgin olive oil speeds up the oxidation of the unsaturated fats.
Treat olive oil as you would other sensitive omega-3 oils by keeping it in a cool and dark place, purchasing smaller bottles instead of larger ones to ensure freshness and immediately replacing the cap after each pour.
• Fusty oil: Your oil should not have a fermented smell to it, reminiscent of sweaty socks or swampy vegetation. See this quality on table olives — brown and mushy Kalamata-style olives exhibit a fusty flavor.
• Moldy olives: If your olive oil tastes dusty or musty, it’s likely made from moldy olives.
• Wine or vinegar flavor: If it tastes like it has undertones of wine and vinegar, it’s probably because the olives underwent fermentation with oxygen, which leads to the sharp, unpleasant flavor.
Follow These Tips When Buying a New Bottle of Olive Oil
If your stash of olive oil has gone rancid and you’re on the hunt for a new bottle, here are some important tips to keep in mind to ensure you’re getting a high-quality product, according to Truth in Olive Oil:34
Harvest date: Look for the harvest date of the olive oil. Top-quality indicators include “early harvest” or “fall harvest.”
Storage and testing: Make sure that the oil you’re buying is stored in stainless steel containers before packaging. The containers should be topped with an inert gas to keep oxygen at bay.
Color and flavor: High-quality extra-virgin olive oil typically exhibits an almost luminescent green color.35 However, note that it can also come in different shades, from gold to pale straw.
Instead, you should examine the odor. High-quality olive oil should smell and taste fresh and fruity. Descriptors include grassy, apple, green banana and herbaceous. It can also be bitter or spicy, the latter being an indicator of health antioxidants. Stay away from moldy, cooked, greasy, meaty or metallic qualities.
Bottle: When canvassing olive oil in stores, look for darkened glass bottles as it prevents light from damaging the product. In terms of amount, make sure you can use the entire bottle within six weeks.
Labeling nomenclature: Always look for (and purchase) extra-virgin olive oil. Other varieties such as “pure” or “light” olive oil, “pomace” olive oil, and simply “olive oil” have typically undergone chemical processing. Don’t be duped by terms like “first pressed” and “cold pressed,” as they are oftentimes meaningless. True extra-virgin oil is taken exclusively from the olive paste’s first processing.
Quality seals: Look for seals from organizations such as the California Olive Oil Council (COOC) and the Australian Olive Association (AOA), which have stricter quality standards compared to the USDA. Other seals may not as trustworthy.
"USDA certified organic" is good but is not the only consideration. PDO (protected designation of origin) and PGI (protected geographical indication) may not guarantee quality as well, but they should inspire some confidence.
Storage and use: Remember to store your olive oil in a cool, dark place away from sunlight, as well as returning the cap immediately to the bottle after you pour. Exposure to air can degrade the quality of your oil.
Prolonging freshness: You may slow oxidation by pouring a drop of astaxanthin to your bottle. Note that it will give your oil a red tint. When it turns pale, replace your oil immediately. Alternatively, you can add a drop of vitamin E.36 The only downside to this strategy is that vitamin E is colorless, which consequently won’t indicate freshness. A drop of lutein can also work, and will turn the oil orange.
Go Ahead and Enjoy Olive Oil, but Remember Not to Heat It
Olive oil may be one of the best foods you can add to your diet, as evidenced by numerous studies. However, remember not to heat it to prevent damaging the beneficial compounds. Also, make sure to examine the olive oil in your pantry regularly. If you think that it has gone rancid or developed an undesirable odor, replace it immediately with another high-quality product.