In addition, the rate-limiting enzyme of oleic acid, stearoyl-CoA desaturase (SCD), has been found to cause neurotoxicity by producing MUFA and impairing microglia and macrophages [14]; it also plays a role in the pathogenesis of various diseases, such as obesity, Parkinson’s disease, and Alzheimer’s disease [15–17]. This evidence concerns the gene SCD and Alzheimer disease.