Olive oil may help lower the risk of heart disease, according to preliminary research that also showed it was beneficial as a substitute for butter or mayonnaise.
“Previous studies have linked high consumption of olive oil with better cardiovascular health, particularly in Mediterranean countries where olive oil intake is much higher than in the United States,” lead study author Marta Guasch-Ferre said in a news release.
“Our aim was to investigate whether higher olive oil consumption was beneficial to heart health in the U.S. population,” said Guasch-Ferre, a research scientist in the department of nutrition at Harvard T.H. Chan School of Public Health in Boston.
Researchers found those who ate more than half a tablespoon of olive oil each day had a 15% lower risk of having any kind of cardiovascular disease and a 21% lower risk of coronary heart disease. Replacing one teaspoon of butter, margarine, mayonnaise or dairy fat with the same amount of olive oil lowered the risk of cardiovascular disease by 5% and coronary heart disease by 7%. However, consuming more olive oil didn’t impact stroke risk.
Although olive oil proved to be healthier than butter and margarine, it did not present more benefits than other plant oils like corn, canola, safflower and soybean.
“One interesting thing our study shows is that although olive oil was better than most animal fats and margarine, it was not superior to vegetable oils in this study population,” Guasch-Ferre said. “This means that replacing any type of animal fat with vegetable oils, including olive oil but also others, could be a good strategy to improve cardiovascular health.”
Researchers noted many margarines contained substantial amounts of trans fatty acids when the study began in 1990, so the results may not apply to vegetable margarines now available.
The findings were observational, which means they don’t prove cause-and-effect. However, small intervention studies have found replacing animal fats with olive oil has a beneficial effect on fat levels in the blood.