It’s long been known that the Mediterranean diet is one of the healthiest overall diets.

Now, research shines new light on the ways that one of the diet’s main components — olive oil — helps boost heart health.

Researchers presented their findings today at the American Heart Association’s (AHA) Lifestyle and Cardiometabolic Health Scientific Sessions in Phoenix.

Their analysis of long-term data, dating back to 1990, shows that eating more than 1/2 tablespoon of olive oil per day lowers one’s risk of cardiovascular disease by 15 percent and the risk of coronary heart disease by 21 percent.

While consumption of olive oil has been associated with improved heart health for years, the new research shows these associations with a U.S.-based population for the first time.

“Mostly, these associations have been shown in the past in Mediterranean and European populations,” Marta Guasch-Ferre, PhD, lead author of the study and a research scientist in the department of nutrition at Harvard T.H. Chan School of Public Health in Boston, told Healthline. “But until now, there was no previous study that showed results in a U.S. population.”

New wrinkles

The health benefits of olive oil are well understood, according to Dr. Benjamin Hirsh, director of preventive cardiology at Northwell Health’s Sandra Atlas Bass Heart Hospital in Manhasset, New York.

“Olive oil is a simple way to replace unhealthy, saturated, and trans-fatty acids of animal fats with a source of omega-3 fatty acids that reduce inflammation and improve cholesterol,” Hirsh told Healthline. “It has also been associated with improved vascular function, heart health, and survival.”

Animal-based fats such as margarine, butter, dairy fat, and mayonnaise are less healthy than olive oil when it comes to supporting heart health.

An intriguing detail uncovered in the new study shows that olive oil isn’t the only oil that contains these benefits.

Guasch-Ferre said that researchers also saw positive associations with other plant oils, such as corn or safflower oil, although more research is needed to confirm the effects of plant oils on health outcomes.

“While olive oil was better than animal fat when we did the substitution analysis, they were not superior to vegetable oils,” she explained. “This means that other vegetable oils could be a healthy alternative compared to animal fat, especially because they tend to be more affordable in the U.S. compared to olive oil.”

Guasch-Ferre also pointed out that these findings are consistent with current recommendations that highlight the quality, rather than the quantity, of fat intake.

She adds that the study led to new questions, and more data will undoubtedly add to the overall understanding of the relationship between olive oil and heart health.

“One thing that we couldn’t analyze here was the different types of olive oil — whether it was common olive oil or extra virgin olive oil. There’s some evidence showing that extra virgin olive oil varieties have higher amounts of polyphenols that are associated with better lipid profiles and less inflammation,” she said.

“It would be interesting to see the effects of different varieties, along with the effects of different vegetable oils on health outcomes, along with defining the underlying mechanisms of these associations,” Guasch-Ferre added.

Well-rounded approach

While replacing animal fats with healthier alternatives such as olive or vegetable oil is a strong step toward improved cardiovascular health, it’s hardly the be-all and end-all.

Good heart health also includes physical activity, a balanced diet and, ideally, visits with a doctor to stay on track.

Hirsh cautioned that olive oil by itself is not a miracle cure.

“I believe that focusing on one component of nutrition misses the benefits that derive from the change in the overall dietary pattern,” he said. “It is likely that those [in the study] who switched to consuming more olive oil as a substitute for unhealthy fats probably also enacted changes in their lifestyles to consume healthier food and be more active.”

Anyone who wants to change their diet to promote better heart health can start by adopting the Mediterranean diet. This diet focuses on unrefined, plant-based foods, along with fish, and — of course — plenty of olive oil.

A final note pointed out by both Guasch-Ferre and Hirsh is that the study’s findings are observational. This means that researchers can’t prove cause and effect.

Still, the findings are supported by long-standing medical knowledge surrounding the health benefits of olive oil while adding an intriguing wrinkle surrounding the benefits of other vegetable oils.

“There’s a lot of research showing that plant-based foods, including healthier vegetable oils like olive oil, can have benefits for heart health,” Guasch-Ferre said. “Butter or other fats, which are high in saturated fats, can be harmful for the heart. It’s better to use olive oil for cooking than other animal fat and it’s also better to have olive oil in ingredients rather than other animal fats.”

Medical reference: healthline