A natural health products group is seeking an international patent for an olive leaf extract it says can help prevent or manage insulin sensitivity, including type 2 diabetes.

It claims clinical trials show oral administration of an olive leaf extract containing the olive polyphenols and antioxidants oleuropein and hydroxytyrosol “may have significant benefits in treating, reducing the symptoms of and/or preventing type 2 diabetes, in both at risk subjects and those already with the disease.”
Comvita Ltd subsidiary Apimed Medical Honey Ltd, based in New Zealand, said in its patent application before the World Intellectual Property Organization that in a double blind, placebo controlled trial involving 46 overweight middle-aged men at risk of developing future metabolic syndrome – which can be a precursor to diabetes – supplementation with olive leaf polyphenols for 12 weeks saw significant improvement in insulin sensitivity and pancreatic β-cell responsiveness. This matters because, “for impaired glucose tolerance to progress into diabetes, patients need to become both insulin resistant, and lose pancreatic β-cell secretion capacity,” the application says.

The olive (Olea europaea L.) leaf extract used in the trial was a product sold by Comvita. Participants were told to take four capsules as a single dose once a day, which would deliver a daily total of 51.1mg of oleuropein and 9.7mg of hydroxytyrosol.

Olive leaves now a “valuable commodity”

Apimed said in its patent application that “folk medicine using olive plants to treat diabetes has existed for centuries,” but only recently has research on the medicinal properties of olive products focused on olive polyphenols – particularly oleuropein and hydroxytyrosol (a breakdown product of oleuropein).

“Polyphenols are found in most edible plants, and are considered to deliver the health benefits of chocolate, coffee, green tea, and red wine. Paralleling the growth in scientific knowledge in olive polyphenols, the olive nutraceutical market is expanding. As the concentration of olive polyphenols is far more potent in olive leaves compared to the fruit or olive oil, this once discarded by-product of tree pruning is now a valuable commodity,” it said.

But the expansion in the olive nutraceutical market has not been accompanied by a relaxation in the health claims companies can make in Europe and the United States. As stated by Apimed itself in its application, the European Food Safety Authority allows a health claim linking consumption of olive oil polyphenols to protection of blood lipids from oxidative damage, but so far no similar claim has been approved for glucose homeostasis (blood sugar control). Also, a recent U.S. Food and Drug Administration warning letter provided a sobering reminder for dietary supplement companies to be careful in the claims they make about their products. The letter in January to Pennsylvania-based Exclusive Supplements raised issues including that the FDA considered therapeutic claims (since removed) on the company’s website about its BioRhythm brand Olio product – which contains extra virgin olive oil – established the product was a drug because it was “intended for use in the cure, mitigation, treatment, or prevention of disease,” and such drugs need prior FDA approval.

Other research has found that following a Mediterranean diet has a preventative effect against diabetes. In 2011, a trial within the PREDIMED study showed a Mediterranean diet reduced the risk of type II diabetes by almost 50 percent compared to a low fat diet

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