Olive oil, and especially extra virgin olive oil, is a cornerstone of the Mediterranean diet. Its health benefits have been discovered and confirmed in countless studies, and almost everything it graces becomes more delicious.

Even though humans have been cultivating olives and crushing them into oil for thousands of years, most people still know very little about Liquid Gold. Slick marketing and disconcerted information only add to the confusion.

And while entire courses (even college curriculums) are devoted to its production, health aspects and culinary uses, there are some things everyone should know about this important staple.

All olive oils are not created equal

Olive farmers and olive oil producers face a range of ever-changing conditions and make choices depending on the means at their disposal and the market they are targeting.

Those aiming to produce the gold standard — extra virgin olive oil — need to manage every step of production with skill and determination, not to mention a degree of added costs.

Extra virgin means the oil is free of taste defects and will pass a battery of tests in a lab. It also means the oil contains only the juice of olives, and nothing else.

Quality matters

High-quality extra virgin olive oil not only tastes delicious, it also boasts greater health benefits compared to the lower grades, such as virgin olive oil and pure olive oil.

Even oils that are extra virgin can vary in quality and value. For example, extra virgin olive oils with higher antioxidant levels will have a longer shelf life than others and contain more of the nutrients that we pay extra for.

Bitterness is a good thing

Fresh olives are bitter, so the oil made from fresh olives should be bitter too. In fact, the bitterness is an indication of those healthy nutrients we expect when we choose extra virgin olive oil.

The good news is that people aren’t shying away from bitter flavors like they used to. In other categories like beer, chocolates and coffee, bitter profiles have become ever more popular and associated with well-crafted products.

Keep it fresh

Extra virgin olive oil begins to degrade in quality the moment it’s made. Exposure to air, heat and light dramatically quicken the shelf-life. Most extra virgin olive oil is no longer extra virgin when it is finally consumed.

It’s as if you paid more for a Ferrari, only to drive a Kia your first time behind the wheel.

Look for a harvest date or bottling date on every bottle you buy — the more recent the date, the better. If you can only find a “best by” date, it should be at least a year in the future.

Keep it tightly closed in a cool, dark cupboard. Once you open the bottle (or tin), use it within a month or two.

Use it for everything

By now everyone should know that olive oil can be used in place of less healthy fats in practically every dish.

From poaching and baking to sautéing to deep-frying, substituting butter and seed oils for extra virgin olive oil is not only the healthiest option, but your foods will also taste better too.

A research review published in the scientific journal Nutrients confirms that phenolic compounds play a critical role in the health benefits associated with extra virgin olive oil that are not associated with other olive oil grades.

“The single most important thing to understand is that extra virgin olive oil is a unique food,” Mary Flynn, the lead author and an associate professor of medicine at Brown University, told Olive Oil Times.

“Compared to other oils, refined and non-extra virgin olive oil, or low-fat diet, daily use will improve several risk factors for chronic diseases, such as decreasing blood pressure, blood glucose, oxidation, and LDL and increasing HDL,” she added. “There is no other food, or medicine for that matter, that can improve such a range of risk factors.”

The researchers conducted a systematic review of studies published between 2000 and 2003 that compared extra virgin olive oil to low-fat diets, other oils and oils listed as ‘olive oils’ in the studies.

The narrative review systematically summarized the latest evidence on the protective effects of extra virgin olive oil on disease risk factors.

A criterion included in this review was that the study had to state extra virgin olive oil was used. Most of the published studies provided limited information on the extra virgin olive oil used. Of 281 retrieved articles, 34 articles fulfilled the inclusion criteria for the study.

“Based on current testing in most countries, an oil could meet a standard for ‘extra virgin,’ but it might not have phenols, and it is the phenols that provide the health benefits,“ Flynn said.

Flynn, who is also the founder of The Olive Oil Health Initiative of the Miriam Hospital, added that one of the goals of the research was to separate olive oil’s health benefits associated with phenolic compounds and those that may come from its high content of monounsaturated fatty acids.

“I find it very hard to believe that there are still people who think it is the monounsaturated fat content that provides the health benefits,” she said. “While there are no studies that support monounsaturated fats providing any benefits, there are many studies, some of which are in our review, that clearly show the [monounsaturated fatty acid] content is not the reason for health benefits.

“If it were, then both refined olive oil and canola oil would have health benefits, and they do not,” Flynn added.

Catherine Itsiopoulos, a co-author and professor at RMIT University in Australia, added that extra virgin olive oil is the keystone ingredient behind the health benefits associated with the Mediterranean diet.

“Extra virgin olive oil is one of the most important staples and a highly ranked distinctive ingredient of a traditional Mediterranean diet,” she told Olive Oil Times. “Our study shows that extra virgin olive oil, due to its rich source of polyphenols with anti-inflammatory and anti-oxidant potential, confers these health benefits and not just any type of olive oil.”

The researchers found extra virgin olive oil to be superior for decreasing blood pressure, LDL‑c, LDL oxidation, fasting blood glucose, and improving insulin sensitivity. Extra virgin olive oil also was determined to increase HDL‑c and improve HDL function.

“One of the more interesting findings was evidence of a distinct advantage of extra virgin olive oil for weight loss,” said Flynn.

“More research is needed to better understand which phenols are most protective and the amount of phenol needed in the olive oil to see the benefit,” she added.

In the meantime, the researchers hope these findings can help inform public health policy surrounding nutrition, which they believe to be outdated.

“I have been researching oil for the past 25 years,” Flynn said. “I’ve long been frustrated that health guidelines around the world do not distinguish the different types of oils.”

“Extra virgin olive oil is the juice of the olive and provides unique health benefits, especially compared to other oils,” she added. “The consumer needs to know they are using extra virgin olive oil that has health benefits, meaning it has at least 150 milligrams per deciliter of total phenols. Simply passing the chemical tests is not sufficient.”

Itsiopoulos said more work also needs to be done to dispel common myths about cooking with extra virgin olive oil.

“Extra virgin olive oil, due to its high antioxidant nutrient content, is highly stable during cooking, dispelling the myth that you cannot fry with extra virgin olive oil,” she said.

Despite the work that still needs to be done, both researchers said the review gives consumers plenty of reasons to prefer extra virgin olive oil over other grades of olive oil and cooking oils.

“This review indicates that approximately two tablespoons per day for extra virgin olive oil can improve a range of chronic disease risk factors in as little as three weeks,” Flynn said.

From olive oil producers, Flynn would like to see phenol content featured prominently on labeling and websites. The phenol content of olive oil is highest when first produced. Fresher virgin olive oil has a higher phenol content and therefore offers more health benefits.

She added that producers should also mention harvest dates on their olive oils and specify the amount of time from the harvest to the transformation process. This information would help consumers know which companies are producing the freshest olive oil with maximum health benefits.

“In many food-based dietary guidelines around the world, extra virgin olive oil is categorized in the oils, spreads and added fats section with the recommendation to consume sparingly,” Itsiopoulos added. “Given the evidence on the health benefits of extra virgin olive oil as presented in this paper, its place in food pyramids or plate models needs to be more prominent.”

Looking ahead at future studies, Flynn said more research into the relationship between extra virgin olive oil consumption and type 2 diabetes should be done.

“I was surprised how few studies there are testing the benefits of extra virgin olive oil for type 2 diabetics,” she said. “Studies have shown that lifestyle changes have more benefits for type 2 diabetics compared to medications.”

“We reviewed some studies showing extra virgin olive oil can improve insulin resistance (that is, the ability of insulin to store nutrients including glucose), and insulin resistance is the root cause of type 2 diabetes and metabolic syndrome,” Flynn added. “If more studies could confirm this finding, that would be very important information.”

Flynn predicts future studies could “test how quickly daily use of extra virgin olive oil could improve blood glucose control.”

“Based on the currently available studies, it is likely two tablespoons per day in as little as three weeks, but future studies could examine if the benefits increase over time,” she concluded.

ommon conditions triggered by obesity might be mitigated or prevented by adopting the Mediterranean diet, a new meta-study has found.

The researchers conducted a wide-ranging review of the current scientific literature. They found that following the Mediterranean diet could yield many benefits for obese people and people at risk of obesity.

The authors of the meta-study, published in Current Obesity Reports, noted that hypertension, type 2 diabetes mellitus, several types of cancers or dyslipidemia, a lipid imbalance that often precedes cardiovascular conditions, are among the many diseases frequently diagnosed in obese people.

By reviewing the current scientific literature, the authors found that adopting the Mediterranean diet might reduce oxidative stress, inflammation, thrombosis and endothelial dysfunction.

Following the diet was also linked with weight loss, modulating the gut microbiome and improving lipid profile, immunity and insulin sensitivity.

By limiting inflammation and regulating cholesterol, the Mediterannenean diet was also proven to be a practical step in cancer prevention and reducing cardiovascular disease risks.

According to the World Health Organization, 650 million adults were obese in 2016. Obesity-related diseases are estimated to kill more people than those associated with being underweight in most countries. In addition, WHO data show that 39 million children under the age of five are overweight or obese, double the amount deemed obese in 1980.

The researchers described the Mediterranean diet as characterized by a “high consumption of vegetables, fruit, nuts, cereals, whole grains and extra virgin olive oil, as well as a moderate consumption of fish and poultry and a limited intake of sweets, red meat and dairy products.”

In the meta-study, the researchers analyzed the proven effects of following the Mediterranean diet on the most common obesity-related conditions.

They found that the Mediterranean diet is not associated with weight gain, even with no energy restrictions. A high-fat, unrestricted-calorie Mediterranean diet also was associated with little weight change and less central adiposity compared with a low-fat diet in the long term.

“The Mediterranean diet has the potential to reduce abdominal adiposity, in particular metabolically detrimental visceral fat, independently of weight loss, and can be recommended as a healthy diet choice to individuals with obesity and overweight, particularly at risk of cardiovascular and metabolic disease,” the researchers wrote.

“The Mediterranean diet may be more effective in Southern European populations due to better availability of specific food products, cultural and other factors,” they added.

Another critical health factor of the Mediterranean diet is the composition of its polyphenols.

According to the researchers, “the plant-based components of the Mediterranean diet contain polyphenols that have been shown to reduce insulin resistance and improve cardio-metabolic risk factors.”

“In addition, olive oil and low-to-moderate alcohol intake (especially red wine) also contribute to the benefits of the Mediterranean diet via their polyphenol content,” they added.

The results of the meta-study are likely to be heralded as good news in the fight against the global obesity pandemic. Obesity is associated with a high risk of morbidity and mortality from different non-communicable diseases.

“Of interest, the negative effects of obesity are reversed in part with substantial weight loss,” the researchers wrote. “The composition of the Mediterranean diet has been related to an excellent effect on reducing dyslipidemia.”

“Additionally, [the diet] positively modulates the gut microbiota and immune system, significantly decreasing inflammation mediators, common ground for many obesity-related disorders,” they concluded. “The Mediterranean diet is the healthiest dietary pattern available to prevent several non-communicable diseases, including cardiovascular disease and type 2 diabetes.”