The study explores whether selective memory complaints (SMC), mild cognitive impairment (MCI) and the comorbidity of Metabolic Syndrome symptomatic of peripheral and cerebral hypo-metabolism with corresponding epigenetic shifts in global DNA (deoxyribonucleic acid) methylation (away from nutrient availability and toward biosynthesis) are initiated by chronic metabolic inflexibility, over-activation of the mTOR (mammalian target of rapamycin) pathway, and the deregulation of neural oxidative phosphorylation.