Comvita shares jumped 3% after the natural health and beauty products company said a clinical trial found its olive leaf extract may help men at risk of developing diabetes.
The trial was conducted by the Liggins Institute and involved 47 middle-aged and overweight men at risk of developing type-2 diabetes.
It found olive leaf improved the way insulin is secreted and the way it works.
Comvita's main business is its manuka honey-based products. Its olive leaf business represents a fifth of sales, mainly as a remedy for coughs and colds.
Chief executive Brett Hewlett says the findings still need to be properly checked, but should prompt further research and boost interest in its products.
He says about 20% of Comvita's business is already in the olive leaf complex products, but to date it's been more in line with cough and cold remedies and general health.
Comvita's stock was up 10 cents to $3.70 a share on Thursday.
Last year, Comvita successfully fought off a $2.50 a share takeover bid million by the Singapore food giant Cerebos, arguing it undervalued the firm.
At the time, Comvita chairman Neil Craig insisted the company was worth more than $4 a share.
Mr Hewlett says he would like Comvita to continue to grow and expand and to remain New Zealand-owned if at all possible.
"I guess we're not for sale and we're not interested might be the message that we want to put out there. We just want to get on with our business and do it well".