Abstract
Background: Olive plant leaves (Olea europaea L.) have been used for centuries in folk medicine to treat diabetes, but there are very limited data examining the effects of olive polyphenols on glucose homeostasis in humans.
Objective: To assess the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein, 9.7 mg hydroxytyrosol
per day) on insulin action and cardiovascular risk factors in middle-aged overweight men.
Design: Randomized, double-blinded, placebo-controlled, crossover trial in New Zealand. 46 participants (aged 46.465.5
years and BMI 28.062.0 kg/m2) were randomized to receive capsules with olive leaf extract (OLE) or placebo for 12 weeks,
crossing over to other treatment after a 6-week washout. The primary outcome was insulin sensitivity (Matsuda method). Secondary outcomes included glucose and insulin profiles, cytokines, lipid profile, body composition, 24-hour ambulatory blood pressure, and carotid intima-media thickness.
Results: Treatment evaluations were based on the intention-to-treat principle. All participants took .96% of prescribed
capsules. OLE supplementation was associated with a 15% improvement in insulin sensitivity (p = 0.024) compared to
placebo. There was also a 28% improvement in pancreatic b-cell responsiveness (p = 0.013). OLE supplementation also led
to increased fasting interleukin-6 (p = 0.014), IGFBP-1 (p = 0.024), and IGFBP-2 (p = 0.015) concentrations. There were, however, no effects on interleukin-8, TNF-a, ultra-sensitive CRP, lipid profile, ambulatory blood pressure, body composition, carotid intima-media thickness, or liver function.
Conclusions: Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and
pancreatic b-cell secretory capacity in overweight middle-aged men at risk of developing metabolic syndrome.
Trial Registration: Australian New Zealand Clinical Trials Registry #336317
This study on the benefits of olive leaf polyphenols is definitely impressive. It’s great to see that such a natural and readily available ingredient can have a significant impact on improving insulin sensitivity in middle-aged overweight men. Olive leaf extract has been known for its various health benefits, but this study further reinforces its importance as a superfood. It’s definitely worth exploring and incorporating into our daily routine for a healthier lifestyle. OliveLife.gr presents the extract of the wild Greek olive leaves that could provide you with significant health benefits.