Olive oil has many health benefits, including reducing the risk of dementia, poor heart health, cognitive decline, or premature death.
How beneficial the staple of the Mediterranean diet is depends on how the product is harvested, processed, stored, and used: on farms or mills, in grocery stores, and in your own home.
“The health benefits come from a variety of factors or components of olive oil,” said Dr. Tassos Kyriakides, assistant professor of biostatistics at the Yale School of Public Health in New Haven, Connecticut. “The main one is oleic acid, and it has been shown to have very healthy benefits.”
Also important is the rich amount of polyphenols in olive oil, which are a type of antioxidant that helps protect against cellular damage and inflammation in the body, said Dr. Mercedes Fernández, head of the standardization and research unit at the International Olive Council, an intergovernmental organization based in Spain.
Here’s what you need to know to select the best possible olive oil for your diet.
Harvest and processing
Historically, the brands that maintain high olive oil quality are those that take care of the process from the moment of harvest, Kyriakides said. Oil made from very green olives, carefully harvested and not fully ripe, is the best, as they have a higher concentration of healthy components, he added.
How quickly the olives move from harvest to processing into oil is the next critical step.
“Some companies have their own mills and processors, where in two hours they can take the fruit from the trees, put it in the mill and obtain the product,” Kyriakides said. This minimizes the risk of the fruit oxidizing or fermenting from sitting out for too long after harvest.
No more than a few days should pass between harvest and processing dates, he added.
The way the oil is processed is one of the most important factors in determining whether that product is healthy, experts say. Extra virgin olive oil is the healthiest version because it is cold pressed just once, without high temperatures or chemical solvents. Special processing helps the extra virgin oil retain its nutrients.
Freshness and storage methods.
You might be wondering how you’re supposed to know when brands pick their olives or how soon they process them.
With the growing popularity of consuming olive oil for its health benefits, some companies have included these details directly on product labels. Alternatively, some tags have a QR code that you can scan to read that information on your smartphone.
Either way, be sure to look up the harvest, processing and bottling dates and expiration date to get the freshest oil, experts recommend.
Bottles that take no more than three months to get from harvest to shelf are your best bet, and the farther the expiration date is from the oil’s purchase date, the fresher the product will be, Kyriakides said.
The International Olive Council has recommended that brands limit the expiration date to no more than two years after bottling.
If a brand’s bottle says its harvest season was “23/24,” for example, “that means its harvest lasted from the latter part of 2023 to early 2024,” Kyriakides said. “Others will be very strict: they will say October, September 2023.”
For fans in the United States, getting fresh olive oil doesn’t mean it needs to be imported anymore. It has been made possible by the growth of American producers, especially in California, where there is a climate conducive to the cultivation of native varieties of olive trees and locals can obtain high-quality oil in a much shorter period of time. Georgia, Oregon, Texas and Arizona also produce olive oil, but on a smaller scale.
Like the compounds in tea or chocolate, those in olive oil degrade over time, especially if it is stored in a warm environment or exposed to light or air, said Dr. Selina Wang, associate professor of cooperative extension in fruits and vegetables on a small scale. vegetable processing at the University of California, Davis.
That is why it is essential to store the oil in a cool environment and in a dark glass bottle throughout the life of the olive oil. The importance of a cool environment is also why consuming the oil raw, for example as a salad dressing, is better than using it for cooking. But regardless of how it is consumed, olive oil is much healthier than the highly refined oils you buy at the supermarket, experts said.
If at the supermarket you see extra virgin olive oil stored on a top shelf near big, bright lights and the bottle is hot, that’s a red flag, Kyriakides said.
“I’m not going to buy that oil, because I know it’s been there, it’s already been exposed to that heat,” he added.
In addition to information on harvest and processing dates, another way to measure oil freshness is by taste.
“The more flavor an olive oil has, the more health benefits it has,” since the compounds responsible for them also contribute to the oil’s flavor, said Joseph R. Profaci, executive director of the North American Olive Oil Association, an association industry commercial, via email. “If health is the main factor, consumers should look for products that are strong rather than soft.”
For that reason, Profaci urged that people “get into the habit of opening the bottle of olive oil as soon as you get home and try it,” he added. “That will help them develop a more discerning palate for olive oil. If you pick up that flavor and are disappointed, and especially if it tastes like rancid wax crayons or rancid nuts, take it back to the store and ask for a refund or replacement.”
And once you try it, if the oil is fresh enough, don’t put it on the back burner for special occasions, Wang said.
“You should consume olive oil as soon as possible,” he added, “because the reasons you buy it, which are health and then flavor, diminish as the oil ages.”
Constantly keeping the oil in the refrigerator can extend the protection of the phenolics for another year or two; just be sure to set it out on the counter a bit before putting it in your salad so it warms up to its normal consistency, Kyriakides said.