Olive Leaf Supports Blood Sugar Metabolism
According to a study published online in March 2013, supplementation with olive leaf polyphenols enhances insulin sensitivity in subjects at risk of developing the metabolic syndrome. The metabolic syndrome is a group of risk factors including elevated blood sugar and blood pressure, insulin resistance or glucose intolerance, decreased high density lipoprotein (HDL) cholesterol with elevated triglycerides and abdominal obesity, which increases the risk of heart disease and diabetes.
Forty-six overweight middle-aged men with an average age of 46 years and average body mass index (BMI) of 28 kg/m2 received an olive leaf polyphenol supplement consisting of 51.1 mg oleuropein and 9.7 mg hydroxytyrosol daily or placebo for 12 weeks. Subsequently, the subjects received no treatment for the following six weeks for a “washout” period, followed by the opposite treatment for an additional 12 weeks. The researchers assessed insulin sensitivity, as well as levels of glucose, insulin, lipids and cytokines. Additionally, the investigators evaluated blood pressure, body composition and carotid intima-media thickness, which is a measurement of atherosclerosis.
The investigators found that olive leaf extract supplementation improved insulin sensitivity by 15 percent and pancreatic beta-cell responsiveness (cells that store and release insulin) by 28 percent compared to placebo. The researchers also showed that olive leaf extract supplementation increased levels of the cytokine interleukin-6 and the insulin-like growth factor-binding proteins IGFBP-1 and IGFBP-2, which transport insulin-like growth factor.
The investigators did not find any effect of olive leaf extract on the cytokines interleukin-8 and tumor necrosis factor-alpha, the inflammatory marker C-reactive protein, lipids, liver function, blood pressure, body composition or carotid intima-media thickness.
The investigators concluded, “Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic beta-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome.”
Reference:
de Bock M, et al. PLoS One. 2013;3:e57622.
