Swapping out the butter or other artery-clogging fats in your diet for heart-healthy olive oil may add years to your life, researchers say.
Folks who consume more than 1/2 a tablespoon of olive oil a day are less likely to die from heart disease, cancer, neurodegenerative diseases like Alzheimer's or lung disease when compared to people who consume less of this healthy fat, a new study finds.
It's not just adding olive oil to your diet that staves off death from disease, said study author Marta Guasch-Ferre, a research scientist in the nutrition department at the Harvard T. H. Chan School of Public Health. "We need to pay attention to overall diet quality and lifestyle, and consistent with our results, the key would be to add olive oil into the diet as a substitution of other unhealthier fats."
Olive oil is rich in healthful antioxidants, polyphenols and vitamins, and is a good source of heart-healthy monounsaturated fats. "One may speculate that mechanisms related to the anti-inflammatory and antioxidant properties of olive oil may have played a role in these findings," Guasch-Ferre said.
Olive oil use could also be a marker for a healthier lifestyle. Folks in the study who consumed the most olive oil were more physically active, less likely to smoke and ate more fruits and vegetables than people who consumed less olive oil.
For the study, the researchers analyzed data on more than 90,000 people from the Nurses' Health Study and the Health Professionals Follow-Up Study who were free of heart disease and cancer when the study began in 1990. These folks were followed for 28 years. Every four years, they were asked how often they ate certain foods, including fats such as margarine, butter, mayonnaise, dairy fat and olive oil.
When compared with people who never consumed olive oil, those who consumed more than 1/2 a tablespoon a day had a 19% lower risk of dying from heart disease, a 17% lower risk of dying from cancer, a 29% lower risk of dying from a neurodegenerative disease, and an 18% lower risk of dying from lung disease.
The researchers also developed statistical models to simulate what would happen if a person swapped out 3/4 a tablespoon of margarine, butter, mayonnaise or other vegetable oils with olive oil. This switch reduced the chances of dying from all causes. Substituting olive oil for other vegetable oils such as canola, corn, safflower and soybean didn't have the same effect, the study showed.
The findings are published in the Jan. 11 issue of the Journal of the American College of Cardiology.
Many questions on the potential health benefits of olive oil need answering before broad recommendations on its use can be made, wrote Susanna Larsson in an accompanying editorial. She is an epidemiologist at the Karolinska Institute in Stockholm, Sweden.
For example, Larsson asked, "What is the amount of olive oil required for a protective effect? Are the protective effects confined to polyphenol-rich extra virgin olive oil or are refined olive oil and other vegetable oils as beneficial?"
Nutritionists not involved in the new study point out that eating a healthy, balanced diet is more important than any one food.
It's not just the olive oil that confers these health benefits, it's likely what the olive oil travels with and/or adds flavor to, said Marion Nestle, professor of nutrition, food studies and public health emerita at New York University.
"Olive oil is part of the classic heart-healthy Mediterranean diet," Nestle noted. This style of eating includes lots of fruits and vegetables, whole grains, nuts, seeds and lean protein, and is low in processed foods. "It's never about one food, it's really about dietary patterns," she said.
Olive oil has calories, and they can add up quickly, Nestle pointed out. There are about 120 calories in 1 tablespoon of olive oil.
This isn't a lot of olive oil either, said Meghan McLarney, a dietitian at Nebraska Medicine in Omaha. "A typical salad at a restaurant has about 4 tablespoons of dressing."
Replacing a fat is different from adding one to your diet, and there are easy ways to replace butter and other animal fats with olive oil, she said.
"If a recipe calls for butter, cut out half of the butter and replace it with olive oil," McLarney said. "This blend is a great way of transitioning and introducing a healthier fat but keeping the flavor."
Swapping out butter or margarine for olive oil or infused olive oil can make a great flavoring on whole grains, vegetables and proteins. "You can bake with olive oil, too," she said.