One of the oldest living tree species (native to China), ginkgo biloba’s leaves have long been studied for their potential medicinal benefits. Ginkgo has historically been used as a memory and concentration enhancer, and an anti-vertigo agent. A 2005 study linked regular ginkgo supplement intake to a lower risk for ovarian cancer. The science behind ginkgo as a memory aid is mixed. A 2007 meta-analysis of 15 randomized clinical studies on ginkgo supplementation found no evidence to support cognitive benefits in healthy young people. Furthermore, an NIH-backed study in 2008 found ginkgo wasn’t effective in reducing incidences of dementia and Alzheimer’s disease in healthy older people. But a 2012 study published in Evidence Based Complementary and Alternative Medicine suggested ginkgo may have benefits on working memory in healthy adults.