What Makes Olive Oil Healthy? | The Olive Oil Professor

Not all olive oils are created equal. Some are herbal and grassy, others are fruity and nutty. Some olive oils are bitter, with a bite that kicks at the back of the throat; others are smooth and almost buttery.

But it's not just olive oil’s flavor that varies among producers. Although all olive oils are high in the monounsaturated fatty acids that can help to lower “bad” LDL cholesterol, their specific antioxidant and anti-inflammatory health benefits can also differ dramatically from bottle to bottle.

What are Antioxidants?

The human body is constantly under assault by free radicals, chemical byproducts produced by converting food into energy, exercise, pollution, sun and smoke. Free radicals prey on the electrons of other molecules, a process which can disrupt the structure of internal cells, cause LDL cholesterol to become trapped in artery walls, or even alter the instructions encoded in strands of DNA. The more free radicals an individual’s body contains, the more likely they are to develop chronic diseases like diabetes, cancer and Alzheimer’s.

Antioxidants are the body’s first line of defense against free radicals, fighting them by restoring stolen electrons, repairing DNA and maintaining cell health. Some antioxidants are naturally produced by the body, while others like vitamin C, vitamin E, beta-carotene, selenium and manganese come from consuming nutritious foods like beans, blueberries and artichokes. The more antioxidants a food contains, the more beneficial it is for keeping the body running smoothly.

Olive Oil & Antioxidants

In fruit form, olives are rich in antioxidants that have been shown to decrease inflammation, regulate cholesterol levels, help prevent bone loss and lower blood pressure. They are carried by polyphenols, a type of compound that is also responsible for carrying an olive’s flavor. The more polyphenols in an olive, the stronger are both its taste and antioxidant health benefits.

But polyphenols are fragile. They decrease in number as an olive goes through the oil-making process. “Their concentrations are affected by many variables, such as genetics, growing environment, farming practices, ripeness at harvest and processing conditions,” says Dr. Selina Wang, associate professor of cooperative extension in the department of food science and technology at the University of California, Davis.

Refining olive oil destroys its polyphenols, says Joseph R. Profaci, executive director of the North American Olive Oil Association, and time plays a major role in how many polyphenols stick around after bottling. “As the oil ages or is exposed to heat, oxygen and light, its polyphenol content will diminish,” he explains. So, while olives are high in the polyphenols that carry antioxidants, not all olive oils are equally as antioxidant rich.

Exactly how many polyphenols it takes for an olive oil to be considered antioxidant rich is, however, up for debate. “Consumers need to be wary because there is no standard in the U.S. for how much polyphenol consumption is enough to obtain the perceived health benefits—or even how much may be too much,” says Profaci.

Research suggests that consuming a minimum of two tablespoons and up to four tablespoons of any olive oil daily can provide antioxidant benefits, according to Wang. But even consuming just over half a tablespoon per day may help to lower the risk of heart disease.

How to Find Olive Oil High in Antioxidants

For an olive oil to be rich in antioxidants, it needs to come from a high-quality producer that has optimized their methods to preserve its polyphenols. “The refining process strips out phenols,” says Vincent Ricchiuti, COO and co-founder of ENZO Olive Oil, an award-winning estate-grown and processed oil from California’s San Joaquin Valley. “Only virgin oils have abundant phenols, and extra virgin is the best for antioxidants.”

Among virgin oils, those whose olives were harvested early tend to yield higher levels of antioxidants, according to Wang. But since polyphenols are also naturally bitter, high-antioxidant oils can often have an unpleasant, pungent taste.

To get both a lot of antioxidants and a delicious flavor, producers must also focus on a variety of other factors including “not bruising the fruit after harvest, milling it six to ten hours after harvesting, and keeping the fruit at a low temperature during the process,” says Marie-Charlotte Piro, founder and CEO of Tuscan-made Olio Piro, which has some of the highest antioxidant levels on the market.

The technique used in milling is equally important. Piro’s lenticular, pressure-based filter removes virtually all organic residue from the finished product to produce an oil that doesn’t just have 650 polyphenols per kilogram and 4 mgs of vitamin E per serving, but also has a clean and elegant taste.

While Piro is known to maintain prime bottling freshness for up to a year, it is an outlier in the olive oil game. In general, the more recently an olive oil was bottled, the more likely it is to pack both a flavor and an antioxidant punch, says Ricchiuti who notes “When you are shopping for olive oil, it is important to focus on the harvest date. [If you’re in the U.S.], it takes less time for California olive oils to get from tree to bottle and then to your home pantry, meaning the finished product you’re able to enjoy is much fresher than olive oil imported from Europe. Purchasing olive oil with the COOC [California Olive Oil Council] seal means you are buying fresh, California-grown, 100% extra virgin olive oil.”