Epigenetics is emerging as the missing link among genetic inheritance, environmental influences, and body and brain health status. In the brain, specific changes in nucleic acids or their associated proteins in neurons and glial cells might imprint differential patterns of gene activation that will favour either cognitive enhancement or cognitive loss for more than one generation. Furthermore, the derangement of age-related epigenetic signalling is appearing as a significant risk factor for illnesses of ageing, including neurodegeneration and Alzheimer’s disease (AD). Therefore, better knowledge of epigenetic mechanisms might provide hints and clues in the triggering and progression of AD. Intense research in experimental models suggests that molecular interventions for modulating epigenetic mechanisms might have therapeutic applications to promote cognitive maintenance through advanced age. Our primary goal is to gain comprehension of how the epigenetic mechanisms modulate the CNS in response to the environment. Thus, the epigenetic information gives rise to the deregulation of the expression, resulting in the development of several pathologies, including AD.