The blood pressure improvements could be extrapolated to produce reductions in the risk of coronary heart disease of 9-14%, while the risk of stroke and heart attack may be slashed by 20-22.5%, according to data published in the European Journal of Nutrition.
“With arguably more pronounced effects than on [blood pressure], [olive leaf extract] intake was also associated with physiologically significant reductions in [total cholesterol], LDL-[cholesterol] and [triglycerides] of 0.32, 0.19 and 0.18 mmol/L, respectively, when compared to the control, with no detrimental effect on HDL-[cholesterol],” wrote scientists from the University of Reading (UK), Massey University (New Zealand), and the Australian Commonwealth Scientific Industrial Research Organisation (CSIRO).
“Considering previous trials conducted with statins, the [total cholesterol], LDL-[cholesterol] reductions reported in the present study could equate to an overall CVD risk reduction of 4.2 % and 9.75 %, respectively.”
The researcher recruited 60 pre-hypertensive men, meaning that their systolic blood pressure was between 121 and 140 mmHg and their diastolic blood pressure was between 81 and 90 mmHg. The men were randomly assigned to consume either supplements containing the olive leaf extract (136 mg oleuropein and 6 mg hydroxytyrosol) or a control for six weeks. This was followed by a four week “washout” period before the men crossed over to the other group for another six weeks.
Results showed that the olive leaf extract was associated with significant reduction in 24-hour and day time values of systolic blood pressure of 3.33 and 3.95 mmHg, respectively, while 24- hour and day time diastolic blood pressure decreased 2.42 and 3.00 mmHg, respectively.
The olive leaf extract was also associated with average decreases of 0.32 mmol/L in total cholesterol, and 0.19 mmol/L in LDL cholesterol, while triglyceride levels decreased by 0.18, said the researchers, compared to control.
“A significant impact at population level”
“The present study has strengthened the existing body of evidence that [olive leaf extract] has the potential to favorably modify blood pressure and plasma lipid profiles,” wrote the scientists.
“The magnitude of the risk-lowering potential we describe could have significant impact at population level in countries with high prevalence of CVD. The impact of dietary factors towards CVD risk has informed the provision of a diet rich in fruit and vegetables in the primary prevention of hypertension and raised cholesterol.
“In the near future, there may be enough evidence for this advice to be extended to include phenolic-rich foods. Daily consumption of [olive leaf extract] can result in favorable improvements in several CVD risk factors which could result in a moderate but nonetheless significant reduction in risk, making it a useful addition to a healthy diet and lifestyle,” they concluded.
Source: European Journal of Nutrition
June 2017, Volume 56, Issue 4, pp 1421–1432, doi: 10.1007/s00394-016-1188-y
“Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial”
Authors: S. Lockyer et al.