Having high blood lipids, which includes LDL cholesterol, is a risk factor for heart disease.This study suggests that ingesting extra-virgin olive oil daily may improve cholesterol levels.EVOO with higher antioxidant levels seemed to be most effective.

While heart disease is the No. 1 killer of Americans, it is also possible to prevent it. The American Heart Association promotes tips for prevention with its Life’s Essential 8, eight areas that influence heart health—four of them health behaviors and four of them measurable health factors. The behaviors include eating a heart-healthy diet, engaging in regular physical activity, quitting tobacco and getting healthy sleep. The other factors include managing weight, cholesterol, blood sugar and blood pressure.

Many studies have indicated that olive oil may help promote a healthy cardiovascular system. This is partly due to its heart-healthy monounsaturated fats. But there’s another component of olive oil that may also play a heart-healthy role: polyphenols. 

Polyphenols are powerful plant compounds that exhibit antioxidant properties. Scientists in Greece wanted to take a closer look at the polyphenols in extra-virgin olive oil (EVOO), comparing the benefits of two EVOOs with different levels of polyphenols. Their results were published in Nutrients. Let’s break down what they found.

How Was This Study Conducted?

Researchers recruited two groups of people—one group had hyperlipidemia (high blood lipids, including LDL cholesterol), and the other was a “healthy” group without hyperlipidemia. The hyperlipidemia group had 24 men and 26 women with an average age of 52; the healthy group had 8 men and 12 women with an average age of 49. Researchers split the hyperlipidemia group in half, with one half receiving an extra-virgin olive oil with high phenolic content and the other using an extra-virgin olive oil with lower phenolic content. 

Still, the group taking the extra-virgin olive oil with lower phenolic content took a higher dose of it so that each group’s total daily phenolic content from extra-virgin olive oil was equal. 

The healthy group consisted of 20 individuals who were gender-matched to participants in the other two groups. This group also took either the high- or low-phenolic EVOOs in the same dosages as the hyperlipidemia participants. The reason for this “healthy” group was to see if there were any differences in their blood lipids at the end of the study period, which lasted for four weeks, and to compare the healthy group’s changes in bloodwork to the hyperlipidemia groups’ changes, including differences between genders. 

All participants were instructed to take the olive oil on an empty stomach for faster absorption of the polyphenols, and to continue with their regular diet and activities. They were also asked to not add any supplements or foods high in polyphenols that were not already a part of their normal routine.

What Did This Study Show?

At the end of the four weeks, 22 participants in the lower-phenolic group and 28 in the higher-phenolic group had made it to the end of the study period with a 100% adherence rate. Researchers found that the hyperlipidemia group had greater improvements in blood lipids compared to the healthy group. Specifically, they found that HDL cholesterol—which is the beneficial type of cholesterol—increased, and lipoprotein (a), also called Lp(a) and similar to LDL cholesterol, decreased slightly in the hyperlipidemia group, but not in the healthy group. 

Even though both groups had equal daily phenolic content from olive oil, the group that ingested the higher-phenolic EVOO showed significant improvements in total blood cholesterol compared to the group that consumed the lower-phenolic EVOO at higher doses.

This study does have several limitations, including the small sample size and short study duration. The participants were also from the region in Greece that grows the specific type of olive that was used to make these extra-virgin olive oils, so it is unknown whether these results can be generalized to other populations in other parts of the world. 

Additionally, researchers did not gather dietary information from participants, so it’s unknown what other foods rich in polyphenols they were consuming. Researchers also cannot be confident that the healthy fats in the olive oil didn’t contribute to these results.

How Does This Apply to Real Life? 

Olive oil is one of the staples of the Mediterranean diet. That’s because it’s been shown time and time again to support overall health and lower the risk of certain diseases, including heart disease. Research also suggests that it may lower the risk of dementia-related death. Some folks even take a shot of the heart- and brain-healthy oil every morning, touting extra-virgin olive oil’s anti-inflammatory properties. And while you certainly could do a shot of straight up EVOO each morning, cooking meals and snacks with olive oil throughout the day might be a more palatable option.

We love using olive oil in dressings, like our Citrus Vinaigrette or Basil Vinaigrette. You can create a flavorful dipping oil for your favorite bread by adding herbs and spices to extra-virgin olive oil—or use it to drizzle over veggies. And if you have a bounty of yellow squash or zucchini, you’ll want to try our Olive Oil-Braised Summer Squash. 

It’s important to note that this study used extra-virgin olive oil, not regular olive oil, which is lighter in color and flavor. EVOO is a higher quality oil, while regular olive oil is more refined and neutral in flavor (kind of like canola or vegetable oil). EVOO has to meet more rigorous standards and has more polyphenols—so if you want to up your intake of those, go for the EVOO.

Following a Mediterranean diet eating style makes it easy to incorporate more extra-virgin olive oil into your life. We have several Mediterranean diet meal plans to choose from, depending on your goals. So whether you want more energy, healthier blood pressure or just want to age gracefully and healthfully, we’ve got a plan for you. 

Our Expert Take

This study suggests that taking extra-virgin olive oil on an empty stomach in the morning may help improve blood lipids. While it’s not harmful to ingest EVOO straight with no food, it might not be palatable to some. Find ways to incorporate this healthy oil into your recipes—like we do with our simple Pesto Scrambled Eggs or Pasta al Limone. You can even add a shot of it to your morning smoothie, or simply drizzle it over bread, veggies and pasta.

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