The Effect of Olive Leaf Extract
Patients with diabetes are likely to develop some complications such as retinopathy, nephropathy and neuropathy as a result of oxidative stress and overwhelming free radicals which cause damage to the body. Treatment of diabetic patients with antioxidant-rich foods may be advantageous to attenuate these complications.
Olive leaf extract is known as a traditional anti-hyperglycemic and antidiabetic vegetable food. Its antioxidants and anti-inflammatory compounds help reduce blood glucose levels, reduce the effects of oxidative stress and also minimize other risk factors for diabetes, such as obesity and high cholesterol.
A 2006 study found that the oleuropein compound of the olive leaf extract contributed to the inhibition of hyperglycaemia and oxidative stress, and may therefore be useful in preventing diabetic complications associated with oxidative stress. (1)
Another 2009 study suggests that olive leaf extract may affect glucose-induced insulin release and could also increase glucose uptake by surrounding tissues. (2)
A 2011 review of type 2 diabetes found that olive leaf extract can help improve insulin secretion in cells. (3)
The review states studies that have shown the extract can reduce high levels of glucose (hyperglycemia) and excessive amounts of insulin in the blood and can lower cholesterol and various indicators related to oxidative stress. (3)
The review also refers to a study in which people who received the olive leaf extract lowered their fasting plasma insulin levels. However, post-meal insulin levels were not significantly affected. (3)
In 2012 clinical trials, people who received olive leaf extract showed significantly lower levels of HbA1c insulin and plasma fasting. HbA1c is indicative of hyperglycaemia. Adults were fed 500 mg (0.5gr) of extract daily for 14 weeks. By reducing HbA1c levels and improving insulin sensitivity, olive leaf extract can effectively manage blood glucose homeostasis in humans. (4)
A study in diabetic overweight adults in 2013 found that oleuropein and hydroxytyrosol in olive leaf extract helped to increase insulin sensitivity. The researchers also noted that over an 8-week period of administration of the extract, blood glucose levels stabilized and blood lipid levels decreased. (5)