APOE and Alzheimer disease: Indeed, there are important differences within the RCTs and meta-analyses regarding the level of cognition among the population (healthy, MCI, and AD), the genetic background (e.g., APOE ε4 status has gained increasing importance) [24], the type of supplementation regimens (EPA vs. DHA ratio), and which is the chosen cognitive outcome measure (e.g., MMSE, ADAS-Cog, memory vs. executive tests).