Ginkgo biloba is also taken for many conditions like stroke ,block in blood vessels and memory loss. ginkgo seems to alter insulin secretion and metabolism. It might increase insulin breakdown by the liver, leading to lower insulin levels and increased blood sugar. so if you have diabetes and you are under anti diabetic medication, this herb may reduce the effect of the medicine at higher rate. so one should check with a medical practitioner before heavy intake of ginkgo Biloba when you have diabetes.