Figure 1.

Key dietary molecules that modulate DNA methylation and their link to cognitive changes. The overview shows the interplay between the folate cycle and the methionine cycle, which produce S-adenosyl methionine (SAM) in order to methylate DNA within the brain. Brain DNA methylation has led to cognitive and genetic changes that ultimately could drive to neurodegenerative processes. Abbreviations: adenosine triphosphate, ATP; methionine synthase, MS; S-adenosyl homocysteine, SAH; tetrahydrafolic acid, THF.