The gingko biloba (Maidenhair) tree is native to China. The leaves of the tree have been used in herbal remedies for the treatment of cognitive impairment, dementia, and as a memory booster. The University of Maryland cautions taking gingko when you have diabetes or are pre-diabetic, especially when taking blood glucose lowering medications. Gingko has been shown to alter insulin secretion and metabolism by increasing the breaking down of insulin performed by the liver. It might lower insulin levels and increase blood sugar levels. The National Center for Complementary and Integrative Health (NCCIH) has been working on a more conclusive study about the relationship between gingko biloba and diabetes. The results are pending.