The health effects of dietary fat are controversial.
However, experts agree that olive oil — especially extra virgin — is good for you.
Here are 11 health benefits of olive oil that are supported by scientific research.
Olive oil is the natural oil extracted from olives, the fruit of the olive tree.
But the predominant fatty acid in olive oil is a monounsaturated fat called oleic acid, making up 73% of the total oil content.
Studies suggest that oleic acid reduces inflammation and may even have beneficial effects on genes linked to cancer (, , , ).
Monounsaturated fats are also quite resistant to high heat, making extra virgin olive oil a healthy choice for cooking.
Summary Olive oil is rich in monounsaturated oleic acid. This fatty acid is believed to have many beneficial effects and is a healthy choice for cooking.
Extra virgin olive oil is fairly nutritious.
Apart from its beneficial fatty acids, it contains modest amounts of vitamins E and K.
But olive oil is also loaded with powerful antioxidants.
These antioxidants are biologically active and may reduce your risk of chronic diseases (, ).
They also fight inflammation and help protect your blood cholesterol from oxidation — two benefits that may lower your risk of heart disease (, ).
Summary Extra virgin olive oil is loaded with antioxidants, some of which have powerful biological effects.
Chronic inflammation is thought to be a leading driver of diseases, such as cancer, heart disease, metabolic syndrome, type 2 diabetes, Alzheimer's, arthritis and even obesity.
Extra-virgin olive oil can reduce inflammation, which may be one of the main reasons for its health benefits.
The main anti-inflammatory effects are mediated by the antioxidants. Key among them is oleocanthal, which has been shown to work similarly to ibuprofen, an anti-inflammatory drug ().
Some scientists estimate that the oleocanthal in 3.4 tablespoons (50 ml) of extra virgin olive oil has a similar effect as 10% of the adult dosage of ibuprofen ().
Research also suggests that oleic acid, the main fatty acid in olive oil, can reduce levels of important inflammatory markers like C-reactive protein (CRP) (, ).
One study also showed that olive oil antioxidants can inhibit some genes and proteins that drive inflammation ().
Summary Olive oil contains nutrients that fight inflammation. These include oleic acid as well as the antioxidant oleocanthal.
Stroke is caused by a disturbance of blood flow to your brain, either due to a blood clot or bleeding.
In developed nations, stroke is the second most common cause of death, right behind heart disease (13).
The relationship between olive oil and stroke risk has been studied extensively.
A large review of studies in 841,000 people found that olive oil was the only source of monounsaturated fat associated with a reduced risk of stroke and heart disease ().
In another review in 140,000 participants, those who consumed olive oil were at a much lower risk of stroke than those who did not ().
Summary Several large studies demonstrate that people who consume olive oil have a much lower risk of stroke, the second biggest killer in developed countries.
Heart disease is the most common cause of death in the world (16).
Observational studies conducted a few decades ago showed that heart disease is less common in Mediterranean countries.
This led to extensive research on the Mediterranean diet, which has now been shown to significantly reduce heart disease risk (, ).
Extra virgin olive oil is one of the key ingredients in this diet, protecting against heart disease in several ways (19).
It lowers inflammation, protects “bad” LDL cholesterol from oxidation, improves the lining of your blood vessels and may help prevent excessive blood clotting (, , , , , ).
Interestingly, it has also been shown to lower blood pressure, which is one of the strongest risk factors for heart disease and premature death. In one study, olive oil reduced the need for blood pressure medication by 48% (, , ).
Dozens — if not hundreds — of studies indicate that extra virgin olive oil has powerful benefits for your heart.
If you have heart disease, a family history of heart disease or any other major risk factor, you may want to include plenty of extra virgin olive oil in your diet.
Summary Extra virgin olive oil has numerous benefits for heart health. It lowers blood pressure, protects “bad” LDL cholesterol particles from oxidation and improves the function of blood vessels.
Eating excessive amounts of fat causes weight gain.
However, numerous studies have linked the Mediterranean diet, rich in olive oil, with favorable effects on body weight (, , ).
In a 30-month study in over 7,000 Spanish college students, consuming a lot of olive oil was not linked to increased weight ().
Additionally, one three-year study in 187 participants found that a diet rich in olive oil was linked to increased levels of antioxidants in the blood, as well as weight loss ().
Summary Consuming olive oil does not appear to increase the likelihood of weight gain. Moderate intake may even aid weight loss.
Alzheimer's disease is the most common neurodegenerative condition in the world.
One of its key features is a buildup of so-called beta-amyloid plaques inside your brain cells.
One study in mice showed that a substance in olive oil can help remove these plaques ().
Additionally, a human study indicated that a Mediterranean diet rich in olive oil benefitted brain function ().
Keep in mind that more research is needed on the impact of olive oil on Alzheimer’s.
Summary Some studies suggest that olive oil may combat Alzheimer's disease, but more research is needed.
Olive oil appears to be highly protective against type 2 diabetes.
Several studies have linked olive oil to beneficial effects on blood sugar and insulin sensitivity (, ).
A randomized clinical trial in 418 healthy people recently confirmed the protective effects of olive oil ().
In this study, a Mediterranean diet rich in olive oil reduced the risk of type 2 diabetes by over 40%.
Summary Both observational studies and clinical trials suggest that olive oil, combined with a Mediterranean diet, can reduce your risk of type 2 diabetes.
Cancer is one of the most common causes of death in the world.
People in Mediterranean countries have a lower risk of some cancers, and many researchers believe that olive oil may be the reason ().
The antioxidants in olive oil can reduce oxidative damage due to free radicals, which is believed to be a leading driver of cancer (, ).
Many test-tube studies demonstrate that compounds in olive oil can fight cancer cells (, ).
More research is needed to determine whether olive oil in fact reduces your risk of cancer.
Summary Preliminary evidence suggests that olive oil may reduce cancer risk, but further studies are needed.
Rheumatoid arthritis is an autoimmune disease characterized by deformed and painful joints.
Though the exact cause is not well understood, it involves your immune system attacking normal cells by mistake.
Olive oil supplements appear to improve inflammatory markers and reduce oxidative stress in individuals with rheumatoid arthritis (, ).
Olive oil seems particularly beneficial when combined with fish oil, a source of anti-inflammatory omega-3 fatty acids.
In one study, olive and fish oil significantly improved handgrip strength, joint pain and morning stiffness in people with rheumatoid arthritis ().
Summary Olive oil can help reduce joint pain and swelling from rheumatoid arthritis. The beneficial effects are greatly increased when combined with fish oil.
Olive oil contains many nutrients that can inhibit or kill harmful bacteria ().
One of these is Helicobacter pylori, a bacterium that lives in your stomach and can cause stomach ulcers and stomach cancer.
Test-tube studies have shown that extra virgin olive oil fights eight strains of this bacterium, three of which are resistant to antibiotics ().
A study in humans suggested that 30 grams of extra virgin olive oil, taken daily, can eliminate Helicobacter pylori infection in 10–40% of people in as little as two weeks (49).
Summary Extra virgin olive oil has antibacterial properties and has been found to be particularly effective against Helicobacter pylori, a type of bacterium that can cause stomach ulcers and stomach cancer.
Buying the right kind of olive oil is extremely important.
Extra virgin olive oil retains some of the antioxidants and bioactive compounds from olives. For this reason, it’s considered healthier than the more refined variety of olive oil.
Even so, there is a lot of fraud on the olive oil market, as many oils that read "extra virgin" on the label have been diluted with other refined oils.
Therefore, examine labels carefully to ensure you're getting real extra virgin olive oil. It’s always a good idea to read ingredients lists and check for quality certification.