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In folk medicine, olive oil benefits spread far and wide. People used olive oil as a digestive aid, laxative, and hangover tonic, and even as an aphrodisiac. But nowadays, this amber elixir is more celebrated as a key component of the Mediterranean eating pattern, highly rated for its impact on multiple areas of health.

Riding the coattails of the Mediterranean diet press coverage, olive oil is perhaps misperceived as the healthiest of all day-to-day vegetable oils. While it’s true that all unsaturated fats are healthy when substituted for saturated fats, olive oil may offer some special benefits.

(See also our post What’s the Healthiest Oil? The Winner Is….)

Olive Oil 101

Olive oils on the supermarket shelf vary by how they’re processed after pressing. There are three categories of olive oil, according to the North American Olive Oil Association. Here’s how they’re labeled:

• Extra virgin olive oil. EVOO, as it’s often abbreviated, accounts for 60 percent of retail olive oil purchases. EVOO is pressed mechanically from the flesh of ripe olives and processed without high heat, steaming, or chemical solvents. This light processing spares beneficial plant chemicals. A wide range of extra-virgin olive oils are available, with a variety of flavors. It’s often used as a “finishing” oil drizzled on foods to enhance flavor and aroma.
• Regular or pure olive oil. This the day-to-day option, a good all-purpose cooking oil that’s also fine for sauces, marinades, and salad dressings.
• Light olive oil. The “light” refers to its color and mild flavor, not reduced fat or calories. Light olive oil is made from lower-grade oils and undergoes relatively extensive processing, including high heat, to remove unappealing tastes and odors. It may contain a spritz of more flavorful oils, like EVOO. Light olive oil has a higher smoke point than other options.

Is Extra-Virgin Olive Oil Healthiest?

EVOO is a prominent part of the Mediterranean eating style. But is it the magic ingredient for good health? That’s a hard question to pin down, since Mediterranean diets are also abundant in beneficial fruits and vegetables, fish, and legumes, and lower in less-healthy options like added sugar and highly refined grains.

However, some research suggests that EVOO may confer special health benefits. One reason may be that the lack of heavy processing preserves plant chemicals (phytochemicals) with antioxidant and anti-inflammatory properties. These include sterols, polyphenols, tocopherols (like vitamin E), and terpenoids.

Olive Oil Benefits: Heart Health

Better cardiovascular health is one benefit associated with olive oil. In a major clinical trial, eating a Mediterranean-style diet supplemented with a liter of extra-virgin olive oil per week as the main fat source reduced heart attack, stroke, and death from heart-related causes, compared with a more conventional low-fat diet.

The study was called PREDIMED. It involved 7,477 men and women in Spain at high risk of heart disease. The Mediterranean-type diet emphasizes whole fruits and vegetables, olive oil, and other plant oils rich in unsaturated fat, alongside fish, poultry, and dairy products consumed in low to moderate amounts, and relatively small amounts of red meat and added sugar.

Half of the participants were assigned at random to follow a Mediterranean-style diet supplemented with extra-virgin olive oil or mixed nuts. The other half did not receive free EVOO or nuts and were asked to eat a low-fat diet

Although the study was later revised and republished in June 2018 in The New England Journal of Medicine to correct technical errors, the PREDIMED scientists concluded, “In this study involving persons at high cardiovascular risk, the incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet.”

Olive Oil Benefits: Diabetes Prevention

Studies based on the PREDIMED findings also suggest that the phytochemicals in olive oil may help prevent diabetes. This is based on data from PREDIMED as well as other studies.

Olive Oil Benefits: Brain Health

In a long-term observational study, a diet based substantially on the Mediterranean pattern was linked to lower risk of Alzheimer’s disease. A major clinical trial to further explore the brain-health benefits of Mediterranean-style diets—the Mediterranean-DASH Intervention for Neurodegenerative Delay, or MIND study—will conclude in 2020.

Olive Oil Benefits: Bone Health

Antioxidant chemicals called phenols in olive oil may prevent the loss of bone mass that can lead to osteoporosis. Some research suggests that the polyphenols suppress the activity of specialized cell, called osteoblasts, that break down and recycle old bone.

Olive Oil Benefits: Prostate Cancer Prevention

One research review concluded that the Mediterranean diet pattern, especially its olive oil component, may guard against the development and growth of prostate cancer. These “chemopreventive” powers stem from antioxidant properties of the oil and direct effects on cancer cells.

The Bottom Line

So should you use extra-virgin olive oil only? The research is too preliminary to come to that conclusion. But there is no doubt that olive oil is a centerpiece of the Mediterranean diet pattern, which scores of studies—and a handful of good clinical trials—have linked to better health. Also, olive oil is a flavorful and rich source of unsaturated fats, which are associated with heart health and other benefits.

Leading nutrition researchers advocate an emphasis on the type, not total amount, of fat in healthy diets. This principle is one of the foundations of the 2015-2020 Dietary Guidelines for Americans. Olive oil, as well as other unsaturated plant oils, certainly fit into the healthy eating pattern detailed in the Guidelines.