Olives sweet for Comvita

Trials by the Liggins Institute have found olive-leaf extract to have some benefits for men at risk of contracting diabetes. Photo / Supplied

A successful scientific trial has pushed Comvita's share price to a five-year high and suggests the company's olive-leaf extract may help prevent a form of diabetes in overweight, middle-aged men.

The NZX-listed health company well known for its honey products had its olive-leaf extract examined by the Liggins Institute at the University of Auckland.

The institute found use of the extract improved insulin release and sensitivity in the middle-aged, overweight men who participated in the trial and were at risk of developing type 2 diabetes.

According to Diabetes New Zealand, this variant of the metabolic disorder is when someone's production of insulin slows ortheir body is resistant to the hormone.

A lack of insulin leads to excess glucose in the blood, which can cause kidney disease and other health problems.

Comvita chief executive Brett Hewlett said type-2 diabetes was an "epidemic" and olive-leaf extract therefore had a global market.

"Diabetes is bit of a global epidemic right now. It's estimated around 4 per cent of the New Zealand population suffers from diabetes and in the US it's 8 per cent."

Despite the trial results, Hewlett said the extract was by no means a "silver bullet" for the disease.

"This isn't a cure for diabetes," he said.

"Potentially this is just one of many weapons that healthcare professionals can use and offer up as a potential preventer of diabetes."

Shares in Comvita, which is well known for its honey products climbed to a five-year high following the release of the trial results, and closed up 10c yesterday at $3.80.

The trial involved 45 men who were classed as overweight based on their body mass index. The results had yet to be peer-reviewed but had been submitted for publication in an international medical journal, Comvita said.

"We're already thinking about potential new research products and follow-up research projects we can do," Hewlett said, "and those might lead to other new products or developments."