Extra-virgin olive oil (EVOO) may improve brain health and decrease your risk of cognitive decline, according to researchers from Temple University in Philadelphia and Sapienza University in Rome. The research was published in November 2019 in the journal Aging Cell.1
Led by Dr. Domenico Praticò, the team tested the effects of EVOO supplementation in a diet fed to mice that were genetically predisposed to tauopathies, or neurodegenerative disorders. After six months, they noticed improvements in the animals’ memory and cognition. As noted in the abstract, their findings:
” … demonstrate that EVOO directly improves synaptic activity, short‐term plasticity, and memory while decreasing tau neuropathology in the hTau mice. These results strengthen the healthy benefits of EVOO and further support the therapeutic potential of this natural product not only for AD but also for primary tauopathies.”
Praticò and the team see promising implications for their research, as quoted in Forbes.2 The physician offered this statement in a press release:
“The realization that EVOO can protect the brain against different forms of dementia gives us an opportunity to learn more about the mechanisms through which it acts to support brain health.”
Scientists from New York and Texas recently offered similar findings, as described in a December 2019 review article published in the Parisian journal Revue Neurologique.3 Noting studies from the last several decades, the authors cited common threads across various studies, with EVOO as a potential remediation for the types of tauopathies studied by Pratico’s team:
“We therefore propose that extra-virgin olive oil is a promising tool for mitigating the effects of adverse vascular factors and may be utilized for potential prevention of late-onset Alzheimer disease.”
EVOO Is Also Good for Heart Health
As one of the main components of the Mediterranean diet, EVOO has already earned an impressive health reputation for boosting both brain and heart health, improving the elasticity of blood vessels and decreasing your risk of Alzheimer’s disease and age-related memory decline, according to the report.
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.
In 2014, results from the PREDIMED Study were published in BMC Medicine.4 Physicians from Spain and the U.S. teamed up to investigate the effects of various types of olive oil on cardiovascular disease and mortality. A group of 7,216 participants, ages 55 to 80, who had high cardiovascular risk were included in the clinical trial.
They were randomized into one of three groups: Members of the first group ate a Mediterranean diet supplemented with nuts; the second group ate a Mediterranean diet supplemented with olive oil, and the third group was assigned a low-fat diet.
Follow-up was conducted 4.8 years later. The scientists found that those whose diets were supplemented with olive oil had a 35% risk reduction for cardiovascular disease. Their risk of death related to cardiovascular problems was also reduced by 48%. “The associations between cardiovascular events and extra-virgin olive oil intake were significant in the Mediterranean diet intervention groups and not in the control group,” the authors wrote.
Multiple Types of and Uses for Olive Oil
Olive oil is pressed from fresh olives and is made mainly in the Mediterranean, mostly in Italy, Spain and Greece, and is available year-round. 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. 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.
It can be flavored with herbs and spices, which you can steep in the oil for 10 days or so. It can also be used to moisturize your skin, remove eye makeup or even get paint out of your hair. Some enjoy using it as a safe, natural lubricant for a close shave and as a soothing aftershave. Commonly sold varieties 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
- Pure or “refined” olive oil — Made by combining extra-virgin olive oil and refined olive oil, resulting in a lower-quality product
- Light olive oil — The word “light” is a marketing term that simply refers to the oil’s lighter flavor. It is refined olive oil that has a neutral taste and a higher smoke point
- 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
The Price of Popularity: EVOO Imposters
People everywhere are suddenly using plenty of EVOO, and the popularity of the Mediterranean diet has made olive oil a $ 16 billion-a-year industry. The problem is that this surge in EVOO use and sales has also led to massive fraud and corruption.
Tests reveal anywhere from 60% to 90% of the olive oils sold in American grocery stores and restaurants are adulterated with cheap, oxidized, omega-6 vegetable oils, such as sunflower oil or peanut oil, or nonhuman grade olive oils, which are harmful to health in a number of ways.
“Extra-virgin” olive oil is often diluted with other, less expensive oils, including hazelnut, soybean, corn, sunflower, palm, sesame, grape seed and/or walnut. Adding insult to injury, these are not listed on the labels.
Larry Olmsted, author of “Real Food Fake Food: Why You Don’t Know What You’re Eating & What You Can Do About It,”5 says that consumers’ perceptions of the product might not be accurate. He explains that while Italy is the world’s largest exporter of olive oil, they’re also the world’s largest importer of olive oil, and that not all that comes from Italy is its finest.
This means that a label of “Bottled in Italy” may in fact be true, but that does not necessarily mean that the oil is from Italy, Olmsted says. He adds that olive oil is actually closer to fresh-squeezed fruit juice than many of the other oils we’re familiar with.
So, how do you know if you are buying pure EVOO or a fake? One way to be sure you are purchasing high-quality olive oil is to buy it from specialty retailers that allow you to taste it first. Taste and smell are important factors in determining authenticity.
Ways to determine which cooking oils are best include paying attention to how the oils behave when they’re heated. Studies show that fumes emitted from some cooking oils can potentially be carcinogenic.
Olive oil should only be used cold and not for cooking. 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. A better option for cooking is to use coconut oil or grass fed butter.
How to Identify Defective Olive Oil
Olmsted said that while consumers may believe that the expiration date on a bottle of olive oil is important, what we really should pay attention to is the “pressed on” or harvest date of the oil. Many of the popular brands sold at supermarkets don’t have this date but for those that do, look for one that is less than 6 months old.
How can you tell superior olive oil from an inferior one, or whether or not your olive oil has gone bad? Here are four telltale signs to look out for:
1. Rancidity. If it smells like crayons or putty, tastes like rancid nuts and/or has a greasy mouthfeel, your oil is rancid and should not be used.
2. Fusty flavor. “Fusty” oil occurs when olives sit too long before they’re milled, leading to fermentation in the absence of oxygen. Fusty flavors are incredibly common in olive oil, so many simply think it’s normal. However, your olive oil should not have a fermented smell to it, reminiscent of sweaty socks or swampy vegetation.
To help you discern this particular flavor, look through a batch of Kalamata olives and find one that is brown and mushy, rather than purple or maroon-black and firm. The flavor of the brown, mushy one is the flavor of fusty.
3. Moldy flavor. If your olive oil tastes dusty or musty, it’s probably because it was made from moldy olives, another occasional olive oil defect.
4. Wine or vinegar flavor. If your olive oil tastes like it has undertones of wine and vinegar (or even nail polish), it’s probably because the olives underwent fermentation with oxygen, leading to this sharp, undesirable flavor.
Choosing the Best Olive Oil
If you’re on the hunt for a new bottle, here are some tips to ensure you’re getting a high-quality product:6,7,8
Harvest date — Insist on a harvest date, and try to purchase oils only from the current year’s harvest. Look for “early harvest” or “fall harvest.”
Storage and tasting — Find a seller who stores the oil in clean, temperature-controlled stainless steel containers topped with an inert gas such as nitrogen to keep oxygen at bay, and bottles it as they sell it; ask to taste it before buying.
Color and flavor — Genuine, high-quality extra virgin olive oil has an almost luminescent green color. However, good oils come in all shades, from luminescent green to gold to pale straw, so color should not be a deal-breaker.
The oil should smell and taste fresh and fruity, with other descriptors including grassy, apple, green banana, herbaceous, bitter or spicy (spiciness is indicative of healthy antioxidants). Avoid flavors such as moldy, cooked, greasy, meaty, metallic or resembling cardboard.
Bottles — If buying pre-bottled oil, favor bottles or containers that protect against light; darkened glass, stainless steel or even clear glass enclosed in cardboard are good options. Ideally, buy only what you can use up in six weeks.
Labeling terms — Ensure that your oil is labeled “extra virgin,” since other categories — “pure” or “light” oil, “olive oil” and “olive pomace oil” — have undergone chemical processing. Some terms commonly used on olive oil labels are meaningless, such as “first pressed” and “cold pressed.”
Since most extra-virgin olive oil is now made with centrifuges, it isn’t “pressed” at all, and true extra virgin oil comes exclusively from the first processing of the olive paste.
Quality seals — Producer organizations such as the California Olive Oil Council and the Australian Olive Association require olive oil to meet quality standards that are stricter than the minimal USDA standards.
Other seals may not offer such assurance. Of course, finding “USDA certified organic” is a bonus, but not the only consideration. Though not always a guarantee of quality, PDO (protected designation of origin) and PGI (protected geographical indication) status should inspire some confidence.
Storage and use — Keep your olive oil in a cool and dark place, and replace the cap or cork immediately after each pour. Never let it sit exposed to air.
Prolonging freshness — To slow oxidation, try adding one drop of astaxanthin to the bottle. Astaxanthin is red, so it will tint your olive oil. As the olive oil starts to pale, you know it’s time to throw it away.
Alternatively, add one drop of lutein, which is orange in color. Vitamin E oil is another option, but since it’s colorless, it will not give you a visual indicator of freshness.