Exercício físico, níveis de BDNF e desempenho cognitivo em idosos - revisão de literatura

Abstract

Population aging is considered an important worldwide phenomenon. In view of the high growth of the elderly population in relation to the other age groups and the consequent increase in the incidence of neurodegenerative diseases, there is a need for studies and intervention strategies that may prevent or delay the decline of cognitive function, which leads to loss of functionality and autonomy in the elderly. Physical exercise has been indicated as a strategy with great possibility of benefiting elderly people with cognitive deficit, and thus, to reduce the risk of dementias; the Brain Derived Neurotrophic Factor (BDNF) can act as a sign of these benefits. This review of the literature, therefore, aimed to verify, through the studies analyzed, the effects and benefits of physical exercises on cognitive function in the elderly, healthy or not, considering BDNF levels. Also, identify what type of physical exercise is most effective in raising BDNF levels. For this, a bibliographic search was performed in the Medline, Capes Portal, and PsycINFO databases, using the following terms: physical activity or physical training, BDNF or neurotrophins or neuroplasticity, cognitive performance. Inclusion criteria were considered articles in Portuguese and English, and a sample composed of elderly individuals, healthy or not. Studies that did not relate physical exercise, BDNF and elderly were excluded. The search has occurred between 10/08/2018 and 12/20/2018. Initially, 34 articles were found, of which only 6 were selected. These studies had a sample size of 10 to 49 elderly people, two of which were exclusively female, one exclusively male, and three with both sexes. Regarding the type of exercise, four implemented aerobic exercise program, one used multimodal exercises and one used resistance exercises associated with cognitive activity. Regarding intensity, two used maximum intensity exercise protocols, one used submaximal intensity, two used moderate intensity, and one did not specify the intensity during physical activity. This literature review demonstrated that aerobic exercise is most commonly used to assess BDNF levels in the elderly, as well as a moderate to intense training intensity, which seems to be the type of exercise and intensity most appropriate for better cognitive performance in the elderly with some pathology associated or not.