Physical exercise modulates peripheral levels of brain-derived neurotrophic factor (BDNF): A systematic review of experimental studies in the elderly

Abstract The objective of this study was to conduct a systematic review of studies that analyzed the effect of physical exercise on the peripheral levels of BDNF in elderly individuals. Method We conducted a search in PsycINFO, Biological Abstracts, Pubmed, Web of Science, and Science Direct from 1990 to 2011, using the following keywords: “physical exercise”, “physical activity”, “physical therapy”, “training”, “BDNF”, “neuroplasticity”, “neurotrophins”, “neuroplasticity proteins”, “aged”, “older”, “elderly”. The articles were considered for inclusion in the review if they were studies with elderly, assessed peripheral (serum and/or plasma) BDNF and evaluated an acute exercise or chronic exercise (training). Results Five randomized controlled trial and one randomized non-controlled trial studies were analyzed. Five out of six studies reported a significantly higher BDNF response to aerobic acute exercise and to aerobic or strength training program in healthy elderly and elderly with different pathologies. Conclusion It was not possible to establish a recommendation protocol for the type and intensity of physical exercise required to produce an increase in levels BDNF. However, physical exercise, particularly, moderate-intensity exercises seem to be more effective to promote increase the peripheral levels of BDNF in the elderly.