APOE and Alzheimer disease: Although in men, the highest tertile of most ceramides and sphingomyelins were associated with an increased risk of developing Alzheimer's disease, in women, there were no associations between any of the ceramides and risk of developing Alzheimer's disease, and in women with the highest tertile of most sphingomyelins there was a reduced risk of developing Alzheimer's disease, which was most pronounced among those carrying APOE4 (Mielle et al., 2017).