Physical activity and cognitive function [Attività fisica e funzioni cognitive]

The possible benefits of regular physical activity on intellectual function, and if the exercise may attenuate cognitive deterioration and reduce the risk of dementia are still debated. Several observational studies have shown improvements in cognitive function and reduced risk of dementia in individuals with higher levels of physical activity. However, other cohort studies have failed to detect any association between physical activity, cognitive function and dementia. Randomized controlled trials (RCTs) have provided conflicting results, with some who have demonstrated an improvement in cognitive function, while others have reported equivocal or frankly negative results. In addition, meta-analytic RCTs have reported large differences in the magnitude of cognitive improvement, with moderate to very modest results, highlighting the need for further studies to define the role of physical activity in the prevention of cognitive decline. The mechanisms underlying the benefits of physical activity on cognitive function are not fully understood. One of the phenomena associated with exercise is stimulating neurogenesis in the hippocampus. Physical activity is also capable of increasing the antioxidant defenses through the stimulation of lifespan molecules called sirtuins. Recently it has been shown that the loss of SIRT1 is strictly linked to Alzheimer’s disease. Also alterations of the adrenergic system seem to contribute to its pathogenesis, given the evidence that in the course of Alzheimer’s disease the brain noradrenergic system undergoes changes. In particular the stimulation of beta-adrenergic receptors is involved in the production of pathological amyloid in animal models, with probable involvement of kinases such as GRK2