Diabetes is a metabolic disorder in which a hormone called insulin can no longer regulate the movement of glucose into cells. As a result, glucose remains in the blood where it damages blood vessels and puts individuals at higher risk for heart disease, nerve damage, problems with blood circulation, and possible amputation, blindness, and kidney disease. The consumption of sugar is one of the main causes of obesity and diabetes.
Stevia, a plant native to Paraguay and Brazil but now also grown in Japan and China, has been used to sweeten tea since the 16th century. Despite containing little to no calories, this natural sweetener tastes 200-300 times sweeter than table sugar. Three decades of research on food safety indicate that stevia leaves and extracts are safe to consume. In addition, they indicate that stevia produces no effect on blood glucose or insulin response. As a result, stevia qualifies as a healthful alternative for diabetes control.
In a study published in BMC Complementary and Alternative Medicine, researchers from Armenia investigated whether stevia can help lower blood glucose levels and lower the risk for diabetic neuropathy. Diabetic neuropathy is a type of nerve damage that could occur with diabetes.
For the study, 36 rats were randomly assigned into three groups: a control group given plain water, a group given water containing 20% fructose (a sugar), and a third group given water with 20% fructose and 20mg/kg of stevia leaf powder. Each group received their drinks for a period of three weeks. The research team then examined the hippocampus and amygdala regions of each rat’s brain to measure neuronal and synaptic plasticity. They found that neural vulnerability was lowest in the rats given water with both the 20% fructose and stevia.
Their findings improve our understanding of how, under conditions of intense fructose consumption, the inclusion of stevia leaves in the diet can mediate insulin resistance and help maintain neural plasticity. Further human subject trials will be needed to determine if stevia can lower the risk for diabetic neuropathy for people as well.
Written by Debra A. Kellen, PhD