Potential mechanisms by which exercise could improve cognitive function include increases in cerebral blood flow, increased neurotrophic factors (BDNF, insulinlike growth factor-1 [IGF-1]), downregulation of neurotoxic factors (insulin, C-reactive protein, cortisol, interleukin-6 [IL-6]), and other inflammatory cytokines, prevention or better control of chronic diseases (e.g., hypertension, stroke, diabetes, cardiovascular disease) and prevention of depression (241). This evidence concerns the gene INS and diabetes mellitus.