New insight of exercise on dementia; combinatory effects of physical and cognitive exercise

Dementia is a progressive neurological disorder which is clinically characterized by memory loss, behavioral symptoms, and loss of ability to live a normal life. Dementia patients may have to cope with permanent and irreversible symptoms. Although a new drug for dementia with beta-amyloid-removal function has recently received FDA approval, the effect of delaying the progression of dementia is still insignificant, but the cost is expensive. On the other hand, studies on the effects of exercise in dementia have implied that the incidence of dementia or cognitive decline could be efficiently controlled by exercise. The cognitive neuroprotective effect of exercise was supported by cross-sectional studies in which physically fit seniors showed larger hippocampal or gray matter volumes than unfit seniors. In addition, multiple animal studies demonstrate that exercise promotes neuroplasticity through induction of neurotropic factors, with improved outcomes on cognitive functions. In this review, we discuss the effects of conventional mode of physical exercise, cognitive (neuromuscular) exercise, and combined exercise in the prevention of dementia, and highlight the prospects for new exercise programs using digital technology that are being recently developed to reduce cognitive decline. Exercise should be importantly considered as a non-pharmacological therapeutic strategy for cognitive decline and dementia.