APOE and diabetes mellitus: Most studies controlled for important confounders that influence both diet and neurocognition, as eight (29, 30, 33–39) controlled for education, six (29, 30, 34, 36, 37, 39) controlled for APOE E4 status, and eight (29, 33–39) controlled for ≥1 measure of cardiovascular risk (i.e., diabetes, hypertension).