And why even the healthiest Americans aren’t getting enough
I regularly report about how the Mediterranean diet is the best diet on the planet for your health. (Including immune health, as I discuss on page 4.) Indeed, for 60 years, research has consistently shown this to be true.
After all, it includes fresh, whole, nutrient-dense foods in a balanced diet. And that approach fits with nutritional science and health much better than today’s ridiculous restrictive, fad diets, which avoid entire categories of whole foods altogether.
However, there’s some confusion about what actually constitutes a Mediterranean diet.
Most experts agree that the diet contains plenty of fresh fruits and vegetables, and seafood like anchovies and sardines. But full-fat dairy like cheese and yogurt, along with grass-fed and -finished meat (particularly lamb), are also central to the diet. As I’ve written before, some experts “conveniently” ignore this because it doesn’t fit with their flawed and failed theories about diet and health.
But one thing that everyone agrees on is that olive oil is central to the Mediterranean diet. But here too, there’s some confusion. So…what type of olive oil should you be using? And how much?
Well, here’s the latest science regarding these key questions, along with an update on research showing how olive oil can help improve the health of both your body and brain.
The key role of olive oil for good health
Even in Mediterranean countries like Italy and Spain, the extent to which people follow their namesake diet can vary. But villagers in the interior mountains of Sicily eat a strictly Mediterranean diet. And that includes snacking on olives harvested from local trees and cooking with olive oil.
These Sicilian mountain villagers are reportedly four times more likely to live past the age of 100 than their urban counterparts.1 This makes sense when you consider that in the regions of Italy where olives are cultivated, rates of cancer, dementia, diabetes, heart disease, and other chronic disease are low.
Of course, olive oil’s health effects aren’t just reserved for Italians. Plenty of research shows that the monounsaturated fats in olive oil can reduce everyone’s risk of heart disease. Plus, the oil is rich in polyphenols and phytosterols, which have been shown in studies to protect against heart disease, type II diabetes, and some cancers.
Olive oil also contains tocopherols (natural vitamin E compounds—not just the single, isolated tocopherol typically found in supplements), which support immune function and lower your risk of inflammation, cancer, and heart disease. (Are you seeing a pattern here?)
The oil is loaded with carotenoids (vitamin A precursors) that support your immune system and help keep your eyes and bones healthy as well.
And if all of that weren’t enough, olive oil is a good source of luteolin, a polyphenol that’s been shown in studies to have neuroprotective effects. In fact, researchers have recently been focusing on olive oil’s many brain benefits.
One study in mice found that the polyphenols in olive oil improved learning and performance on memory tests.2 And an animal and laboratory study found that an olive oil polyphenol called oleocanthal can reduce brain toxins associated with declines in language skills and memory in humans.3
The oleocanthal study is one of several showing that olive oil can help protect against Alzheimer’s disease. In fact, it dovetails with another study that found that compounds in the fat component of high-grade olive oil help flush out neurological toxins and keep brain cells communicating with each other.4 This can help prevent and even reverse Alzheimer’s and other dementias.
The mystique of extra virgin olive oil
One thing all of these studies have in common is that they used extra virgin olive oil (EVOO). This type of oil is derived from the first, cold-pressing of ripe olives. (Learn more about how EVOO is defined in the sidebar).
There is evidence that EVOO is higher in oleocanthal and another polyphenol known as oleacein. But a large part of the health benefits of olive oil are due to oleic acid, which is found in all types of the oil—not just the extra virgin variety.
You see, olive oil is complicated, containing many different important compounds. And scientists just happen to like studying the compounds that are more prevalent in EVOO. But you can bet the Sicilians I mentioned earlier—not to mention a bunch of other Mediterraneans—consume all of the olive oil from their presses (not just the limited amounts of EVOO).
In fact, they’ve learned that manufacturers and consumers will pay a premium for EVOO, so they ship it off, and use the other, “lower” grades themselves—without missing all the beneficial effects, so far, on their own health.
That’s because what really matters when it comes to consuming olive oil is the “dose”—not whether it’s extra virgin. And the sad fact is, the vast majority of Americans don’t even get close to the optimum amount of olive oil for good health.
The healthiest “dose” of olive oil
In a new study of nearly 100,000 American men and women, researchers found that barely 10 percent of the participants consumed 4.5 grams of olive oil a day (a single measly teaspoon).5
And yet, the study found that consuming just 7 grams of olive oil a day (about half a tablespoon) decreased the participants’ risk of cardiovascular diseases by an impressive 14 percent. And their coronary heart disease risk, specifically, was even lower—by 18 percent.
Meanwhile, the Mediterranean diet PREDIMED study included nearly 7,500 Mediterranean men and women, ages 55 to 80, with a high risk for cardiovascular disease.6 The study participants’ mean baseline consumption of olive oil was 38 grams per day—or more than eight times what the top 10 percent in the American study consumed.
The PREDIMED researchers increased some of the participants’ olive oil consumption to 50 grams a day (a little less than 4 tablespoons). These participants also ate a Mediterranean diet.
Researchers followed the study participants for an average of 4.8 years. By the end of the study, they discovered that the group who consumed 50 grams of olive oil had as much as a 39 percent lower risk of cardiovascular diseases.
And the researchers reported that for every extra 10-gram increase in olive oil consumption per day, cardiovascular disease risk decreased by an additional 7 percent.
But you don’t have to consume as much as they did in the PREDIMED study to reap the heart and general health benefits of olive oil. Indeed, I recommend at least 2 tablespoons (26 grams) a day.
The best ways to choose and use olive oil
Whether you choose costly EVOO or not, there are two factors you need to consider when buying and storing olive oil…
1.) A dark glass bottle helps protect your oil from decomposition due to light exposure. So does storage in a cool, dark place. You can also buy olive oil packaged in metal drums, which keeps out all light. But whatever you do, don’t choose olive oil in plastic containers. Plastics may contain toxic chemicals like bisphenol A (BPA).
2.) Once you open an olive oil bottle, it begins to degrade. That’s why I recommend only purchasing as much as you’ll use in three months. (Although unopened bottles of well-produced and packaged oil can stay fresh for 18 to 24 months.) You can always give your oil a taste test to make sure it’s still fresh and potent. A pungent, slightly bitter taste means the oil’s polyphenols are still active.
Olive oil is great for cooking because, unlike many other plant oils, it can be safely heated to 400 degrees or higher. Plus, sautéing vegetables and other foods in olive oil extracts much greater proportions of the healthy nutrients in these foods. That’s why we won’t cook with any other type of oil in our house.
EVOO: How to make sure you’re getting the “real deal”
Extra virgin olive oil (EVOO) is a shifting target, as manufacturers manipulate the market. But if you really want the high-cost, high-grade oil used in some studies, here’s what you need to know.
Standards of flavor and quality for EVOO are said to correspond to antioxidant content (which in itself is a tricky concept). Some standards are set by the International Olive Council (IOC), based in Spain, but they’re hardly definitive.
The IOC defines EVOO as “virgin olive oil which has a free acidity, expressed as oleic acid, of not more than 0.8 grams per 100 grams.”
The U.S. Department of Agriculture goes a little further. It defines EVOO as having “excellent flavor and odor (median of defects equal to zero and median of fruitiness greater than zero) and a free fatty acid content, expressed as oleic acid, of not more than 0.8 grams per 100 grams.”
It’s no surprise that these somewhat subjective and wishy-washy standards have yielded a veritable vat of mislabeled (to put it charitably) EVOO. After all, isn’t “excellent flavor and odor” in the eye of the beholder? (Like a fine wine, or wine vinegar.)
Five years ago, an analysis by the National Consumers League found that more than half of products labeled as EVOO failed to meet IOC standards, including olive oil from natural grocers such as Trader Joe’s and Whole Foods.9 And things haven’t improved since then.
Last November, olive growers and a producer petitioned the U.S. Food and Drug Administration (FDA) to adopt “science-based, enforceable standards” for EVOO and other types of olive oil. And for good measure, they recommended modern testing standards to ensure olive oil freshness.10 But there’s no word yet on what the FDA plans to do.
California, on the other hand, has a standardized testing process for EVOO that includes a chemical analysis, sensory evaluation, and olive traceability.11 EVOO that makes the grade can carry a California Oil Council seal. So, for now, that’s your best bet to ensure the EVOO you buy is truly extra virgin—if you still really want to.
2“Extra Virgin Olive Oil Improves Learning and Memory in SAMP8 Mice.” 1 Jan. 2012 : 81 – 92.
3“Extra‐virgin olive oil ameliorates cognition and neuropathology of the 3xTg mice: role of autophagy.” Ann Clin Transl Neurol, 4: 564-574.
4“Extra‐virgin olive oil ameliorates cognition and neuropathology of the 3xTg mice: role of autophagy.” Ann Clin Transl Neurol. 2017 Jun 21;4(8):564-574.
5“Olive Oil Consumption and Cardiovascular Risk in U.S. Adults.” J Am Coll Cardiol. 2020 Apr 21;75(15):1729-1739.
6“Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts.” N Engl J Med. June 21, 2018; 378:e34.