It’s no secret that health experts love the Mediterranean diet, which consistently snags the #1 spot on U.S. News & World Report's list of best diets. But while it features a variety of nutrient-rich foods, some researchers believe that the Mediterranean diet’s abundance of healthy fats—particularly from olive oil—is what gives it an edge.
Compared to many other cooking oils, olive oil is loaded with predominantly health-promoting monounsaturated fats, along with a slew of potent polyphenol compounds linked to everything from pain relief to improved cognitive health.
Here, discover the science-backed health benefits of olive oil, how to find the highest quality olive oil, and how to preserve its benefits while cooking.
What makes extra virgin olive oil so healthy?
Most research citing health benefits of olive oil reference extra virgin olive oil. That’s because EVOO is minimally processed and produced via mechanical extraction (by crushing olives and separating the oil from the fruit pulp)—a method that helps preserve the oil’s delicate polyphenols and other micronutrients.
In general, polyphenol compounds (found in olive oil and other plant foods) are believed to reduce morbidity and slow the development of cardiovascular diseases, neurodegenerative diseases, and cancer. The main ones present in extra virgin olive oil include oleuropein, hydroxytyrosol, and oleocanthal, which possess anti-inflammatory, antioxidant, and anti-microbial properties.
Regular olive oil (often just labeled "olive oil") is also healthy, but may not be quite as healthy as EVOO. It contains a combination of refined olive oil and about 15%-25% virgin olive oil. The refined component is treated with mild heat and chemical compounds to remove flavor defects, which results in somewhat reduced levels of beneficial compounds like polyphenols, according to a 2018 study. (Keep in mind, though, even regular olive oil is much more nutritionally potent than most other cooking oils.)
Thanks to its abundance of health-promoting compounds, high quality olive oil has been linked to a number of exciting health benefits. Here are some of the most promising research-backed ways olive oil may improve your health.
Olive oil and cardiovascular health
The positive impact of olive oil on cardiovascular and heart health has been well studied. In the landmark PREDIMED study from 2013, which included over 7,000 adults in Spain, the participants consuming a Mediterranean diet supplemented with either mixed nuts or extra virgin olive oil (4+ tablespoons per day) had a significantly lower risk of experiencing a major cardiovascular event compared to those eating a low-fat control diet. The risk of combined stroke, heart attack, and death from heart disease was 28% lower in the Mediterranean diet with nuts group and 31% lower in the Mediterranean diet and olive oil group.
More recently, new research presented at the American Heart Association’s EPI Scientific Sessions demonstrated that olive oil has a positive impact on health, even for people outside of Mediterranean regions. After accounting for diet and lifestyle factors, researchers found that participants (all living in the U.S.) who ate more than half a tablespoon of olive oil per day had a 15% lower risk of all cardiovascular disease and a 21% lower risk of coronary heart disease.
A range of smaller studies have also linked extra virgin olive oil to improvements in cholesterol (in particular, the olive oil’s polyphenols seem to help prevent “bad” LDL cholesterol from oxidizing into a more harmful form), and significant reductions in blood pressure.
Olive oil and cancer
People living in Mediterranean regions have lower rates of cancer compared to other populations—and research indicates that olive oil is partially to thank. While more studies are needed, one large 2011 research review found that women with the highest levels of olive oil in their diet had a lower risk of breast cancer and cancers of the digestive system, including colon cancer. Other research finds that olive oil, along with other elements of a Mediterranean style diet, may help reduce risk of certain types of skin cancer, including melanoma.
Olive oil’s anti-cancer properties are believed to come from its polyphenol compounds. Oleuropein, hydroxytyrosol, oleocanthal, and others have been shown to reduce inflammation, induce apoptosis (programmed cancer cell death), and interfere with the ability of cancer cells to grow new blood vessels and spread to other parts of the body (metastasize).
Olive oil and brain health (dementia)
Olive oil’s potent polyphenols may even keep your memory sharp as you age. A growing body of evidence suggests that the polyphenol oleocanthal may be to thank. Findings of a 2019 mouse study suggest that consumption of oleocanthal-rich extra virgin olive oil may help slow or halt the progression of Alzheimer’s disease. The oleocanthal-rich EVOO was shown to restore blood brain barrier function and improve other aspects of brain health by reducing neuroinflammation.
Olive oil and inflammation + pain
Chronic inflammation is a driver of many types of pain, and by making strategic dietary shifts (think: ditching the processed, pro-inflammatory foods in favor of nutrient-rich whole foods) can go a long way in quelling that inflammation. In fact, a Mediterranean diet has been shown in various studies to reduce the development and progression of osteoarthritis, a painful joint condition. Olive oil, in particular, may be a key element to a pain-fighting diet. Not only is it rich in monounsaturated fats, which have been shown to exhibit favorable anti-inflammatory benefits (especially when eating them in place of saturated fats), but research shows that the polyphenol compound oleocanthal has similar anti-inflammatory properties to ibuprofen.
Additionally, because consistent low doses of ibuprofen have been shown to have anti-cancer and anti-thrombotic (i.e. blood clot-preventing) effects, researchers speculate that consistent low doses of oleocanthal-rich foods like EVOO could reduce risk of a range of chronic inflammatory diseases.
Olive oil and weight loss
Olive oil is helping put an end to the myth that fat makes you fat. In recent study, women with excess body fat who supplemented their breakfast with approximately 1.5 tablespoons of extra virgin olive oil experienced significantly greater weight loss and reduction in blood pressure than women consuming an equal amount of soybean oil, prompting researchers to recommend that EVOO be included in programs for obesity treatment. These findings support an earlier study on more than 7,000 college students, which found that higher consumption of olive oil was not associated with weight gain over the course of 28 months.
Olive oil and mental health
Thanks to the emerging field of nutritional psychiatry, researchers are learning that, yes, we can eat our way to mental wellbeing. In 2019 study, researchers found that young adults with depression who followed a Mediterranean-style diet (containing vegetables, fruit, whole grains, fish, lean meats, tofu, beans, and about 2 tablespoons of extra virgin olive oil per day) reduced depression symptoms to a “normal” range after 3 weeks, along with stress and anxiety.
This supports findings published in the landmark SMILES Trial from 2017, which showed that a 12-week Mediterranean diet intervention resulted in around 30% of participants going into remission for their depression; as well as an animal study, which suggest that the oleic acid, polyphenols, and other compounds in extra virgin olive oil support the nervous system, making it a potentially useful dietary intervention for people with depression and anxiety.
Olive oil and gut health
Keeping your digestive system running smoothly and countering gut-related conditions is crucial to overall physical and mental health, researchers are learning. That’s, in part, because the good bacteria in our gut microbiome communicate with and influence the brain as the immune system. Luckily, olive oil can give your gut a boost.
A 2019 research review found that the polyphenols in olive oil may be beneficial at quelling gut inflammation and improving immunity—making it beneficial for people with irritable bowel diseases such as ulcerative colitis and Crohn’s. One study included in the review found that daily consumption of about 1.5 tablespoons of extra virgin olive oil increased populations of bifidobacteria (a type of healthy gut bacteria) as well microbial metabolites responsible for antioxidant activity.
Other research has found that olive oil contains antimicrobial nutrients that can help combat H. pylori infections, caused by a harmful bacteria that can cause stomach ulcers and even cancer.
Olive oil and immunity
Olive oil contains compounds that contribute to an optimally functioning immune system, which is important for everything from warding off cancer to battling the common cold. A 2015 study compared the effect of consuming 3 tablespoons of extra virgin olive oil per day vs 3 tablespoons (total) of butter, soybean oil, and corn oil. Researchers found that the immune T cells in the EVOO group increased their ability to become activated (and grow in number) by about 53%, while the activity of the other group’s T cells remained unchanged. The olive oil polyphenol hydroxytyrosol also helps immune cells make a compound called interleukin-10, which helps calm inflammation.
Olive oil and bone health
Prioritizing calcium and vitamin D aren’t the only important strategies for boosting bone health. In a 2018 study of over 500 women in Spain, researchers found significant increases in bone mineral density among those with a higher intake of olive oil—even after adjusting for factors such as intake of calcium, vitamin D, and body mass index (BMI). Research suggests that olive oil polyphenols help maintain bone density via mechanisms involving bone formation, the prevention of bone resorption (breakdown), and reduction in oxidative stress and inflammation.
Olive oil and type 2 diabetes
More and more, researchers are learning that a diet rich in healthy fats—along with a reduction in refined carbohydrates—is important for the management and even reversal of type 2 diabetes. A 2017 meta-analysis found that people consuming the most olive oil had, on average, a 16% reduced risk of developing type 2 diabetes as well as significant reductions in fasting blood sugar and HbA1c levels (an indicator of your average blood glucose over two to three months). Additionally, a number of studies support the beneficial effects of a Mediterranean diet for reducing type 2 diabetes risk and improving overall metabolic health.
How to find the healthiest olive oil
Clearly, extra virgin olive oil can be incredibly healthy, but how do you know you’re getting a good product? Turns out, quality can differ significantly, depending on the olives used, a company’s manufacturing practices, and how long a bottle’s been sitting on the shelf.
According to Dr. William Li, M.D., internal medicine physician and author of Eat to Beat Disease, olive oils made from Koroneiki, Picual, and Moraiolo cultivars tend to have high levels of polyphenols. Other high polyphenol varieties include Coratina, Picholine and Mission. So scan your labels before making a purchase. Retailers who specialize in olive oil are more likely to carry these monovarietals. And robust earlier harvest oils will have higher polyphenol levels than mild late harvest oils.
Another way to identify if your EVOO packs a polyphenol punch? Pour a bit into a small cup then take a small sip as you would with a wine tasting—aerating it a bit as you move it from the front to the back of your palate. You should notice a somewhat bitter, peppery taste (it might even make you cough), which is an indicator of a high polyphenol content. A pleasant grassy, vegetal, or floral flavor is also a good sign. But it should never smell or taste rancid.
Does heating olive oil negate its health benefits?
Contrary to popular belief, you can still cook with extra virgin olive oil. While using EVOO on salads, as a dipping oil, or as a finishing oil for roasted veggies will preserve the most nutrients, it has a surprisingly high smoke point of 350 to 410 F—meaning that cooking techniques such as sauteing and even roasting are still on the table.
EVOO may actually be more stable and produce fewer harmful byproducts than other oils when heated to high temperatures, thanks to its protective antioxidants. In a 2018 study, 10 common cooking oils were heated for 20 minutes until they reached 464 F, and extra virgin olive oil produced the least oxidative byproducts, trans fats, and other unhealthy compounds.
Olive oil is an incredible source of good fats and health-promoting compounds—and it may hold the secret to why people in Mediterranean region seem to be some of the healthiest on the planet. Try incorporating a few tablespoons of this liquid gold into your meals per day if you don’t already. But just remember, like any food, olive oil doesn’t work miracles on its own. The compounds in olive oil act synergistically with other healthful compounds in your diet, so your best bet is to combine it with other nutrient-rich fare typical of a Mediterranean diet, including a diverse array of veggies, fruits, whole grains, legumes, fish, olives, nuts, and seeds.