If you had to pick just one oil to use in the kitchen…make it this one. Olive oil has the well-earned reputation of being a healthy fat that’s perfect for finishing dishes or in a salad dressing, and now has even entered the coffee arena. But it turns out that olive oil may be even more versatile than previously thought. Let’s delve into how olive oil is made, the different types, the nutrient content, and the supporting research for it to be your new go to oil for just about everything.
Olive oil is extracted by pressing or crushing olives, the fruit of the olive tree. The first step involves harvesting the olives at the optimal stage of ripeness. The olives are then cleaned to remove any debris, and the leaves and stems are discarded. The next phase can vary, depending on the desired quality and type of olive oil. The oil can be extracted through mechanical methods or with chemicals. Chemical processing includes refining (heat, chemicals and other processes used to change the taste, color and other characteristics of the oil), treating with an alkaline solution, degumming, bleaching, and deodorization. The main types of olive oil include:
- Extra Virgin Olive Oil (EVOO): Extra virgin olive oil is the highest quality and most flavorful type of olive oil. It is not refined or chemically treated, rather it is produced by the traditional method of cold-pressing olives without the use of heat or chemicals. It has a low acidity level (below 0.8%) that retains the natural flavors, aroma, and antioxidants.
- Virgin Olive Oil: Virgin olive oil is also obtained through the cold-pressing process, but it has slightly higher acidity (up to 2%) compared to extra virgin olive oil. It has a milder flavor.
- Pure Olive Oil: Pure olive oil is a blend of extra virgin olive oil and refined olive oil. Refined olive oil is obtained by refining virgin olive oil using mechanical and chemical processes. It lacks the distinct flavors and many of the health benefits of extra virgin olive oil.
- Light Olive Oil: The term “light” refers to the oil’s light flavor and color rather than its nutritional content; light olive oil is not lower in calories or fat than other olive oils. It is a refined olive oil that undergoes further processing to remove impurities and flavors. Light olive oil is often used in recipes where a mild taste is desired or for baking. Extra light olive oil is further refined and is very mild in flavor.
- Pomace Olive Oil: Pomace olive oil is extracted from the pulp and pits (or pomace) left over after the initial pressing of olives. It undergoes extensive refining processes and is considered the lowest grade of olive oil. It lacks the flavor and health benefits of extra virgin olive oil.
Extra virgin olive oil stands out because it retains the most beneficial compounds from the olive. This translates to more health benefits, so much so that health enthusiasts have been known to take it by the tablespoon. It also seems to be a key contributor to the success of the Mediterranean diet (1). So, what are the key compounds that EVOO contains that make it so impressive?
- Fatty Acids: EVOO is primarily composed of monounsaturated fatty acids (MUFAs), with oleic acid being the most abundant. MUFAs are considered healthier fats compared to saturated and trans fats, and they contribute to the oil’s stability and health benefits.
- Polyphenols: EVOO contains a range of natural antioxidants called polyphenols. These include phenolic compounds such as hydroxytyrosol, tyrosol, and oleuropein. Polyphenols have been associated with numerous health benefits, including anti-inflammatory and antioxidant properties that neutralize free radicals.
- Vitamin E: EVOO is a good source of vitamin E, particularly alpha-tocopherol, which acts as an antioxidant and helps protect cells from oxidative damage.
- Phytosterols: Phytosterols are plant compounds that resemble cholesterol in structure. Extra virgin olive oil contains various phytosterols, including beta-sitosterol, which may help reduce cholesterol absorption and promote heart health.
- Squalene: Squalene is a hydrocarbon compound found in EVOO. It has antioxidant and potential anticancer properties and is known for its moisturizing and skin-nourishing effects.
- Pigments: EVOO contains natural pigments such as chlorophyll, carotenoids (including beta-carotene), and phenolic compounds. These pigments contribute to the oil’s color and may have additional health benefits.
It’s worth noting that the health benefits of EVOO are often attributed to the ways these compounds interact with each other in the body. Regular consumption of EVOO as part of a balanced diet has been associated with decreased blood pressure, lower levels of chronic inflammation, increased insulin sensitivity, improved heart health, and other positive health outcomes (2).
Considering that the health benefits of EVOO are related to the limited processing, does the additional “processing” we do in the kitchen, such as frying and baking, negate the benefits? Are we banished to throwing back raw EVOO to reap the benefits to preserve the sensitive compounds? You might be relieved to hear that new research indicates that, out of all the cooking oils, EVOO has the greatest oxidative stability and is quite safe to use at high temperatures (3).
The temperature at which an oil begins to produce smoke and break down, potentially creating harmful compounds, is called the “smoke point.” Many people believe that using olive oil for high-heat cooking is unhealthy due to its relatively low smoke point compared to other oils. However, the smoke point alone does not determine an oil’s safety or health benefits.
Despite its lower smoke point, EVOO is a stable and healthy oil, thanks to its rich composition of antioxidants and polyphenols. These compounds contribute to its ability to withstand heat and oxidative stress. That translates into the fact that EVOO can be safely used for a variety of cooking techniques, including sautéing, baking, and roasting, without compromising its health benefits. It’s important to focus on the quality and freshness of the olive oil used, rather than solely fixating on its smoke point. High-quality EVOO found in dark bottles can be used for cooking at moderate temperatures without sacrificing its nutritional value or introducing harmful compounds.
It’s certainly understandable if you can’t get on board with adding a splash of EVOO to your latte, but in view of what we now know about it, you may wish to consider using it in just about every other method of cooking.
References:
- Harvard Health Publishing. (n.d.). Is extra-virgin olive oil extra healthy? Retrieved from https://www.health.harvard.edu/nutrition/is-extra-virgin-olive-oil-extra-healthy
- Marcelino G, Hiane PA, Freitas KC, Santana LF, Pott A, Donadon JR, Guimarães RCA. Effects of Olive Oil and Its Minor Components on Cardiovascular Diseases, Inflammation, and Gut Microbiota. Nutrients. 2019 Aug 7;11(8):1826. doi: 10.3390/nu11081826. PMID: 31394805; PMCID: PMC6722810.
- Guillaume C., et al., “Evaluation of Chemical and Physical Changes in Different Commercial Oils during Heating”. Acta Scientific Nutritional Health 2.6 (2018): 02-11. https://actascientific.com/ASNH/pdf/ASNH-02-0083.pdf
