Written by Matthew J Leach^a , Ian Breakspear^b

Diabetes mellitus affects an estimated 529 million adults worldwide.¹ Maintaining optimal glycaemic control is a cornerstone of diabetes management as it reduces the risk of complications from the condition.² Despite this, evidence suggests that fewer than one-half of patients meet their target HbA1c levels (a measure of long-term glycaemic control)³, which poses a significant challenge to diabetes management. Recent studies suggest that olive leaf extract (OLE) could play a potential role in diabetes management⁴, although clinical evidence has been limited, until now.

The Efficacy and Safety of Olive Leaf Extract for Diabetes (ESOLED) trial aimed to address this evidence gap by examining the clinical effectiveness of OLE on HbA1c levels, insulin resistance, diabetes-related distress and health-related quality of life.⁵ The ESOLED trial was a 24-week, randomised, placebo-controlled study involving adults with type 2 diabetes, from across Australia, who were not using insulin therapy. Participants were randomly assigned to either the OLE or placebo group, and were required to complete a clinical assessment at 0, 12 and 24 weeks.

The results from the 31 participants were mixed. While no statistically significant improvements were observed in HbA1c, diabetes distress or quality of life between the OLE and placebo groups, the OLE group did show a trend towards better insulin sensitivity. However, this difference was not enough to reach statistical significance. Fortunately, both OLE and placebo were well-tolerated, with no severe adverse events reported.

At this stage, the ESOLED trial provides initial evidence that OLE is safe for adults with type 2 diabetes but falls short in proving its effectiveness in managing glycaemic control or improving diabetes-related outcomes. The findings of this trial point to the need for more robust pharmacokinetic studies of OLE to determine how best to optimise the bioavailability of OLE for clinical use, and to unlock OLE’s full potential in diabetes management.

Author affiliations

^aJBI, University of Adelaide, King William Road, North Adelaide, SA, 5005, Australia

^bFaculty of Health & Education, Torrens University Australia, Bowen Terrace, Fortitude Valley, QLD, 4006, Australia

Funding

The ESOLED trial was supported by an Olive Wellness Institute Research Grant, as well as donations from Vital.ly Pty Ltd and Oborne Health Supplies.

Published 24/03/2025

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