What Is Olive Oil and How Is It Made?

Olive oil is oil that has been extracted from olives, the fruits of the olive tree.

The production process is incredibly simple. Olives can be pressed to extract their oil, but modern methods involve crushing the olives, mixing them together, and then separating the oil from the pulp in a centrifuge.

After centrifugation, small amounts of oil remain in the pomace. The leftover oil can be extracted using chemical solvents and is known as olive pomace oil.

Olive pomace oil is generally cheaper than regular olive oil and has a bad reputation.

Buying the right type of olive oil is crucial. There are three main grades of olive oil — refined, virgin, and extra virgin. Extra virgin olive oil is the least processed or refined type.

Extra virgin olive oil is considered to be the healthiest type of olive oil. It's extracted using natural methods and standardized for purity and certain sensory qualities like taste and smell.

Olive oil that is truly extra virgin has a distinct taste and is high in phenolic antioxidants, which is the main reason why it's so beneficial.

Legally, vegetable oils that are labeled as olive oil cannot be diluted with other types of oils. Nevertheless, it's essential to inspect the label carefully and buy from a reputable seller.

Nutrient Composition of Extra Virgin Olive Oil

Extra virgin olive oil is fairly nutritious.

It contains modest amounts of vitamins E and K and plenty of beneficial fatty acids.

One tablespoon (13.5 grams) of olive oil contains the following:

• Saturated fat: 14%
• Monounsaturated fat: 73% (mostly oleic acid)
• Vitamin E: 13% of the Daily Value (DV)
• Vitamin K: 7% of the DV

Notably, extra virgin olive oil shines in its antioxidant content.

Antioxidants are biologically active, and some of them can help fight serious diseases.

The oil's main antioxidants include the anti-inflammatory oleocanthal, as well as oleuropein, a substance that protects LDL (bad) cholesterol from oxidation.

Some people have criticized olive oil for having a high omega-6 to omega-3 ratio (over 10:1). However, its total amount of polyunsaturated fats is still relatively low, so this shouldn't be a cause for concern.

Extra Virgin Olive Oil Contains Anti-Inflammatory Substances

Chronic inflammation is believed to be among the leading drivers of many diseases, including heart disease, cancer, metabolic syndrome, diabetes, and arthritis.

Some speculate that olive oil's ability to fight inflammation is behind its many health benefits.

Oleic acid, the most prominent fatty acid in olive oil, has been found to reduce inflammatory markers like C-reactive protein.

However, the oil's main anti-inflammatory effects seem to be due to its antioxidants, primarily oleocanthal, which has been shown to work like ibuprofen, a popular anti-inflammatory drug.

Researchers estimate that the amount of oleocanthal in 50 ml (about 3.4 tablespoons) of extra virgin olive oil exerts effects similar to those of 10 percent of the adult ibuprofen dosage for pain relief.

Also, one study showed that substances in olive oil can reduce the expression of genes and proteins that mediate inflammation.

Keep in mind that chronic, low-level inflammation is usually fairly mild, and it takes years or decades for it to do damage.

Using extra virgin olive oil may help prevent this from happening, leading to a reduced risk of various inflammatory diseases, especially heart disease.

Extra Virgin Olive Oil and Cardiovascular Disease

Cardiovascular diseases, such as heart disease and stroke, are among the most common causes of death in the world.

Many observational studies show that death from these diseases is low in certain areas of the world, especially in countries around the Mediterranean Sea.

This observation originally spurred interest in the Mediterranean diet, which is supposed to mimic the way the people in those countries eat.

Studies on the Mediterranean diet show that it can help prevent heart disease. In one major study, it reduced heart attacks, strokes, and death by 30 percent.

Extra virgin olive oil protects against heart disease via numerous mechanisms:

• Reducing inflammation. Olive oil protects against inflammation, a key driver of heart disease.
• Reduces oxidation of LDL (bad) cholesterol. The oil protects LDL particles from oxidative damage, a key factor in the development of heart disease.
• Improves blood vessel health. Olive oil improves the function of the endothelium, which is the lining of the blood vessels.
• Helps manage blood clotting. Some studies suggest that olive oil can help prevent unwanted blood clotting, a key feature of heart attacks and strokes.
• Lowers blood pressure. One study in patients with elevated blood pressure found that olive oil reduced blood pressure significantly and lowered the need for blood pressure medication by 48 percent.

Given the biological effects of olive oil, it's not surprising that people who consume the greatest amounts of it are significantly less likely to die from heart attacks and strokes.

Dozens — if not hundreds — of animal and human studies have shown that olive oil has major benefits for the heart.

In fact, the evidence is strong enough to recommend that people who have or are at a high risk of developing heart disease include plenty of extra virgin olive oil in their diets.

Other Health Benefits of Extra Virgin Olive Oil

Although olive oil has mostly been studied for its effects on heart health, its consumption has also been associated with a number of other health benefits.

Olive Oil and Cancer

Cancer is a common cause of death and characterized by the uncontrolled growth of cells.

Studies have shown that people living in the Mediterranean countries have a fairly low risk of cancer, and some have speculated that olive oil has something to do with this.

One potential contributor to cancer is oxidative damage due to harmful molecules called free radicals. However, extra virgin olive oil is high in antioxidants that reduce oxidative damage.

The oleic acid in olive oil is also highly resistant to oxidation and has been shown to have beneficial effects on genes linked to cancer.

Many test-tube studies have observed that compounds in olive oil can help fight cancer at the molecular level.

That said, controlled trials in humans have yet to study whether olive oil helps prevent cancer.

Olive Oil and Alzheimer's Disease

Alzheimer's disease is the world's most common neurodegenerative disease and a leading cause of dementia.

One feature of Alzheimer's is a buildup of protein tangles called beta-amyloid plaques in certain neurons in the brain.

A study in mice observed that a substance in olive oil can help clear these plaques.

Additionally, a controlled study in humans showed that a Mediterranean diet enriched with olive oil improved brain function and reduced the risk of cognitive impairment.

Can You Cook With It?

During cooking, fatty acids can oxidize, meaning they react with oxygen and become damaged.

The double bonds in fatty acid molecules are mostly responsible for this.

For this reason, saturated fats, which have no double bonds, are resistant to high heat. Meanwhile, polyunsaturated fats, which have many double bonds, are sensitive and become damaged.

Olive oil contains mostly monounsaturated fatty acids, which have only one double bond, and is fairly resistant to high heat.

In one study, researchers heated extra virgin olive oil to 356°F (180°C) for 36 hours. The oil was highly resistant to damage.

Another study used olive oil for deep-frying, and it took 24–27 hours for it to reach damage levels that were deemed harmful.

Overall, olive oil seems to be very safe — even for cooking at fairly high heat.

The Bottom Line

Olive oil is super healthy.

For those who have heart disease or are at a high risk of developing it, olive oil is most definitely a superfood.

The benefits of this wonderful fat are among the few things that most people in nutrition agree upon.