A study on a standardized olive fruit extract shows promise for consumers at risk of arterial stiffness, as measured by a reduction in triglycerides. The extract showed less effect when measured with a vascular index.
In a recent study published in the journal Drugs R&D, a standardized olive fruit extract (Proliva, supplied by Euromed) improved scores on an arterial measurement index as well as in measurements of mean triglyceride for the higher dosage group.The authors noted that arterial stiffness is an important risk factor for cardiovascular disease and mortality. The researchers chose to measure this with something called the Cardio-Ankle Vascular Index, a measurement tool that has been gaining traction among cardiovascular researchers. The index, which was first proposed in 2008, derives a stiffness parameter by plotting the natural logarithm of systolic-diastolic pressure ratio against the arterial wall extensibility.According to a 2013 review paper , the index has the advantage of being theoretically independent of blood pressure, as higher pressure naturally would put more stress on the arterial wall and cause it to appear to be more stiff. “CAVI has been widely applied clinically to assess arterial stiffness in subjects with known cardiovascular diseases including those with diagnosed atherosclerosis, coronary heart disease, and stroke as well as those at risk, including those with hypertension, diabetes, the elderly, and the obese,” the authors of the 2013 paper wrote.
Modest benefit showing need for more research
In the most recent olive extract study, the Euromed researchers divided 36 subjects in the double-blind, placebo-controlled study into three groups, one receiving 250 mg of the extract daily, which delivered 50 mg of the active ingredient, hydroxytyrosol, a 500 mg dose (100 mg of hydroxytyrosol) or a placebo. The subjects, who were all between the ages of 45 and 65, were followed for 11 days.Measurements at the end of the study showed no statistical differences between the groups in the CAVI measurement, with all three improving slightly. The authors said that a larger-scale, longer term study could better define the placebo effect, but did note that the high dose extract group did show the biggest improvement in the measure of blood triglyceride levels, and had the largest CAVI improvement, which they said showed a trend toward “improved arterial elasticity”. More research could better define this benefit, they said. The researchers also included a Visual Analog Scale (VAS) questionnaire portion of the study, looking at various parameters of ‘energy,’ including tiredness, fatigue and appetite, by which it was determined that the extract was well tolerated.