Scientists from La Trobe University have found that high-polyphenol extra virgin olive oil may help reduce blood pressure in healthy adults.
The study, led by Katerina Sarapis and published in the journal Nutrients, adds to growing evidence that certain compounds in extra virgin olive oil can support cardiovascular health.
Extra virgin olive oil is a staple of the Mediterranean diet, which is widely associated with lower rates of heart disease and longer life expectancy.
Countries such as Spain, Italy and Greece are among the largest producers in the world.
Unlike regular olive oil, which is refined and stripped of many of its natural compounds, extra virgin olive oil is produced through a natural extraction process that preserves the nutrients and antioxidants present in the olive fruit.
Extra virgin olive oil contains more than 30 different phenolic compounds.
These include powerful antioxidants such as oleacein, tyrosol and hydroxytyrosol, which help protect the body against oxidative stress and inflammation caused by free radicals.
Polyphenols are naturally occurring plant compounds found in fruits, vegetables, teas and spices, and they are known to support heart health. By definition, high-phenolic olive oil contains at least 250 milligrams of polyphenols per kilogram of oil.
In this study, the researchers compared the effects of high-polyphenol extra virgin olive oil and low-polyphenol olive oil on blood pressure and arterial stiffness in healthy adults.
Arterial stiffness is an important marker of cardiovascular health and is associated with an increased risk of heart disease, dementia and premature death.
A total of 50 participants consumed 60 millilitres per day of either high-polyphenol olive oil, which contained 360 milligrams of polyphenols per kilogram, or low-polyphenol olive oil, which contained 86 milligrams per kilogram, for a period of three weeks.
After a two-week break, known as a washout period, participants switched to the other type of olive oil.
Researchers measured body composition, peripheral blood pressure, central blood pressure and arterial stiffness before and after each phase of the study.
Peripheral blood pressure is measured at the arm, while central blood pressure reflects the pressure in the main artery leaving the heart, known as the ascending aorta.
Central blood pressure was assessed using a device called a tonometer, which is placed over the artery to measure pulse waves.
The results showed that participants who consumed the high-polyphenol olive oil experienced a significant reduction in systolic blood pressure.
Peripheral systolic blood pressure decreased by an average of 2.5 mmHg, while central systolic blood pressure decreased by approximately 2.7 mmHg. No significant changes were observed in diastolic blood pressure or in measures of arterial stiffness for either group.
Systolic blood pressure represents the pressure in the arteries when the heart contracts, while diastolic blood pressure represents the pressure when the heart relaxes between beats. Even small reductions in systolic blood pressure can meaningfully lower the risk of heart disease and stroke at a population level.
The researchers concluded that the reduction in systolic blood pressure seen after consuming high-polyphenol extra virgin olive oil provides further evidence of its potential cardiovascular benefits in otherwise healthy individuals.
They suggest that longer-term studies, as well as studies using higher doses of polyphenols, may help clarify whether extra virgin olive oil can also influence diastolic blood pressure and arterial stiffness over time.
