Study supports traditional diabetes therapy claim

13 March 2013

A clinical trial by researchers at The University of Auckland’s Liggins Institute has shown that an extract of fresh olive leaves appreciably reduces some risk factors for developing type 2 diabetes.

A paper published today in the peer-reviewed journal PLOS ONE presents results of the randomized, double-blinded, placebo-controlled, crossover trial of the extract in 46 overweight, middle-aged men at risk of developing type 2 diabetes and cardiovascular disease. The extract was prepared and supplied by global natural health and beauty products company Comvita.

Principal investigator and Liggins Institute Director Professor Wayne Cutfield said that supplementation with the olive leaf extract for 12 weeks improved the way that insulin was secreted and worked in overweight men. Insulin is an important hormone which controls metabolism by stimulating the transport of glucose and fat into cells.

“We saw significant improvements in standard measures of insulin action and secretion compared with placebo. The changes were of similar magnitude to those achieved with the commonly prescribed diabetes medication metformin, suggesting that these results could also have clinical relevance for patients with type 2 diabetes,” said Cutfield.

Comvita CEO Brett Hewlett said the study underscores the potential for efficacious, proven natural products to play an integral role in improving health outcomes.

“Many natural supplements and remedies depend on traditional evidence found in national pharmacopoeias, text books and published reviews. This clinical trial provides important scientific rigour supporting the use of fresh olive leaf extract to improve glucose regulation in at-risk overweight middle aged men.”

Cutfield observed that the nutraceutical industry is a growing economic force. “People deserve to know whether marketing claims are real and justified.

Previously, there has been little rigorous scientific evidence to support the centuries-old use of olive leaves as a remedy for ill-health, including diabetes.

“We welcome the opportunity to bring our expertise in conducting well designed clinical trials into partnership with natural products companies such as Comvita to provide objective evidence of products’ effectiveness,” he said.

The article, “Olive (Olea europaea L.) leaf polyphenols improve insulin sensitivity in middle-aged overweight men: a randomized, placebo-controlled, crossover trial,” is available on line:

The research was co-funded by Comvita and the New Zealand Government, as part of a programme of business R&D funding now administered by Callaghan Innovation, the Crown entity charged with accelerating commercialisation of innovation in New Zealand firms.

Further information:
Pandora Carlyon, Communications Manager, Liggins Institute, 021 565 715