The researchers found that the olive leaf extract lowered insulin resistance by an average of 15% and increased the productivity of the pancreas' beta cells – which produce insulin - by 28%.
Insulin sensitivity was measured using a glucose tolerance test, which measures glucose and insulin levels in the blood every thirty minutes. pancreatic beta cell function was measured using the Matsuda method of glucose/insulin curve measurements.
The researchers concluded:
"Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic β-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome."