Many studies have looked at the health benefits of olive oil. Extra virgin olive oil, which is the best quality oil available, is rich in antioxidants, which help prevent cellular damage caused by molecules called free radicals.

Free radicals are substances that the body produces during metabolism and other processes. Antioxidants neutralize free radicals.

If too many free radicals build up, they can cause oxidative stress. This can lead to cell damage, and it may play a role in the development of certain diseases, including certain types of cancer.

Olive oil and the cardiovascular system

Olive oil is the main source of fat in the Mediterranean diet. People who consume this diet appear to have a higher life expectancy, including a lower chance of dying from cardiovascular diseases, compared with people who follow other diets. Some experts call it “the standard in preventive medicine.”

A 2018 study compared the number of cardiovascular events among people who consumed a Mediterranean diet, either with olive oil or nuts, or a low-fat diet.

People who consumed the Mediterranean diet, whether with olive oil or nuts, had a lower incidence of cardiovascular disease than those on the low-fat diet.

According to the authors of one 2018 review, the Food and Drug Administration (FDA) and the European Food Safety Authority recommend consuming around 20 grams (g) or two tablespoons (tbs) of extra virgin olive oil each day to reduce the risk of cardiovascular disease and inflammation.

Results of a 2017 study suggested that the polyphenols in extra virgin olive oil may offer protection from cardiovascular disease, atherosclerosis, stroke, brain dysfunction, and cancer. Polyphenols are a type of antioxidant.

Metabolic syndrome

Metabolic syndrome is a condition characterized by a group of risk factors that increase disease risk, including obesity, high blood pressure, and high blood sugar levels.

Authors of a 2019 meta-analysis concluded that olive oil in a Mediterranean diet might improve features of metabolic syndrome, such as inflammation, blood sugar, triglycerides (fats in the blood), and low-density lipoprotein (LDL), or “bad” cholesterol. In contrast, it appears to increase levels of high-density lipoprotein (HDL), or “good” cholesterol.

Depression risk and olive oil

In 2013, a rodent study suggested that ingredients in extra virgin olive oil may help protect the nervous system and could be useful for treating depression and anxiety.

Two years before, scientists had found evidence that people who ate trans fats, which is an unhealthful fat that features in fast foods and pre-made baked goods, were more likely to have depression than those who consumed unsaturated fats, such as olive oil.

Olive oil and cancer risk

Some studies have suggested that substances in olive oil may help reduce the risk of breast cancer, but not all findings confirm this.

According to research published in 2019, olive oil contains substances that may help prevent colorectal cancer. Lab tests have found evidence that antioxidants in olive oil may help protect the body from inflammation, oxidative damage, and epigenetic changes.

Alzheimer’s disease

In 2016, some scientists suggested that including extra virgin olive oil in the diet may help prevent Alzheimer’s disease. This may be due to its protective impact on blood vessels in the brain.

Authors of a mouse study published in 2019 suggested that consuming oleocanthal-rich extra virgin olive oil could help slow or stop the progression of Alzheimer’s. Oleocanthal is a phenolic compound that occurs in extra virgin olive oil.

Olive oil and the liver

A 2018 review of laboratory studies found that molecules in extra virgin olive oil may help prevent or repair liver damage.

The oil’s MUFAs, which are mainly oleic acid, and its phenolic compounds appear to help prevent inflammation, oxidative stress, insulin resistance, and other changes that can result in liver damage.

Olive oil and inflammatory bowel disease

Inflammatory bowel disease (IBD) causes inflammation of the digestive tract. Ulcerative colitis and Crohn’s disease are types of IBD.

A 2019 review found that phenols in olive oil may help boost intestinal immunity and gut health by changing the microbes in the gut. This could be useful for people with colitis and other types of IBD. The authors noted that more human studies are needed to confirm these results.