Phenolic-Rich Olive Leaf Extract Beneficial for Blood Pressure and General Vascular Health

by | Jul 6, 2017 | 2016, Antioxidants, Blood Lipids, Blood Pressure, Cardiovascular Health, Olive Leaf Extract

Written by Angeline A. De Leon, Staff Writer. Thirty days of twice daily supplementation with 10 mL of extra strength olive leaf extract significantly decreased daytime and 24-hour average systolic and diastolic ambulatory blood pressures in participating subjects.

blood pressureThe Mediterranean Diet has grown increasingly popular in recent years, with scientific evidence supporting its relationship to improved cardiovascular health 1. Such effects are largely due to the diet regimen’s promotion of high olive oil intake 2, which has been shown to reduce inflammation, cholesterol, and atherosclerosis 3. Although the exact mechanism is still under study, the lipid-lowering effects of olive oil are thought to involve phenolic compounds (powerful antioxidants which help protect blood lipids from oxidative stress) contained in the leaves of the olive plant 4. The phenolic component of olive leaf extract (OLE) decreases cholesterol biosynthesis and increases excretion of biliary cholesterol 5,6, and human research has shown that general improvement in vascular function is specifically tied to phenolic-rich vs. phenolic-poor olive oil 4. It remains inconclusive, however, whether phenolic-rich OLE also affects plasma lipids, ambulatory blood pressure (ABP), and/or inflammatory markers 7,8. In a 2017 study published in the European Journal of Nutrition, researchers sought to clarify the impact of phenolic-rich OLE on 24-hour ABP as well as various measures of vascular and metabolic function.

A total of 60 pre-hypertensive males (mean age = 45 years) participated in a double-blind, randomized, controlled, crossover trial. For six weeks, in random order, all subjects were assigned to ingest either 10 mL of extra strength OLE with food twice per day or a polyphenol-free control product consisting of vegetable glycerin and water. The alternating arms of the study were separated by a 4-week wash-out period during which no products were consumed. Participants provided blood samples for analysis of biochemical measures, and at weeks 0, 6, 10, and 16, 24-hour ABP was assessed.

The following key findings were obtained for OLE treatment vs. control:

Blood Pressure: Significant decreases were found for daytime systolic ABP (-3.95 +/- 11.48 mmHg, p = 0.027) and 24-hour average systolic ABP (-3.33 +/- 10.81 mmHg, p = 0.045), as well as daytime diastolic ABP (-3.00 +/- 8.54 mmHg, p = 0.025) and 24-hour average diastolic ABP (-2.42 +/- 7.61 mmHg, p = 0.039).

Plasma Lipids and Inflammatory Markers: Significant decreases were found for plasma total cholesterol (-0.32 +/- 0.70 mmol/L, p = 0.002), LDL cholesterol (-0.19 +/- 0.56 mmol/L, p = 0.017), and triglycerides (-0.18 +/- 0.48 mmol/L, p = 0.008). Interleukin-8 (a pro-inflammatory signaling molecule) was also lowered (-0.63 +/- 1.13 pg/mL, p = 0.026).

Overall results lend evidence to support OLE’s potential to effectively alter blood pressure and other markers of vascular health. From a treatment perspective, the lipid-lowering effects of OLE and other phenolic-rich foods can be used to strengthen current clinical strategies of heart disease prevention. However, as study results are limited to an all-male sample, current findings should be interpreted cautiously.

Source: Lockyer S, Rowland I, Spencer JPE, et al. Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomized controlled trial. European Journal of Nutrition. 2016; 56: 1421-1432. DOI: 10.1007/s00394-016-1188-y.

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Posted July 6, 2017.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program.

References:

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