The pistachio (Pistacia vera), a member of the cashew family, is a small tree originally from Central Asia and the Middle East.Based on the research at Pennsylvania State University, it was found that pistachios significantly reduce levels of low-density lipoprotein (LDL cholesterol) while increasing antioxidant levels in the serum of volunteers. Preliminary studies show pistachios have antibacterial activity against the intestinal pathogens Escherichia coli and Listeria monocytogenes.