Effects of Resistance Exercise on Neuroprotective Factors in Middle and Late Life: A Systematic Review and Meta-Analysis

Abstract

Neuroprotective factors are involved in brain functioning. Although physical exercise has been shown to have a positive influence on these factors, the effect of resistance exercise on them is not well known. This systematic review and meta-analysis aimed to 1) estimate the efficacy of resistance exercise on major neuroprotective factors, such as insulin-like growth factor-1 (IGF-1), brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF), in middle and late life and 2) determine whether the effect is dose dependent. A systematic search was conducted in CINAHL, Cochrane CENTRAL, MEDLINE, Scopus, PEDro, SPORTDiscus, and Web of Science up to November 2022. Random effects models were used to estimate standardized mean differences (SMDs) and their respective 95% confidence intervals (CI) for the effect of resistance exercise on peripheral IGF-1, BDNF or VEGF levels in older adults. Thirty randomized clinical trials with 1247 subjects (53.25% women, 45-92 years) were included in the systematic review, and 27 were selected for the meta-analysis. A significant effect of resistance exercise on IGF-1 levels was observed (SMD: 0.48; 95% CI: 0.27, 0.69), being more effective when performing 3 sessions/week (SMD: 0.55; 95% CI: 0.31, 0.79) but not on BDNF (SMD: 0.33; 95% CI: -0.29, 0.94). The effect on VEGF could not be determined due to the scarcity of studies. Our data support the resistance training recommendation in middle and late life, at a frequency of at least 3 sessions/week, to mitigate the neurological and cognitive consequences associated with aging, mainly through IGF-1.

Prevention of Vascular Contributions to Cognitive Impairment and Dementia: The Role of Physical Activity and Exercise

“…Physiological adaptations associated with RT are particularly beneficial for cerebral white matter, and results from early studies demonstrate that RT may be a promising strategy to prevent or slow WMH progression. 21,22…”

“…97 While primarily secreted by the liver, IGF-1 is also expressed by contracting muscles, particularly following RT compared with AT. 22,84…”

Effects of non-pharmacological interventions for adults with subjective cognitive decline: a network meta-analysis and component network meta-analysis

“…Among the forms of physical activity interventions, resistance exercise might be most effective in reducing subjective memory complaints in adults with SCD. This effect may be related to the fact that resistance exercise can increase blood flow to memory-related brain regions [ 33 ], produce neuroprotective factors [ 34 ], and achieve greater neuronal survival and synaptogenesis [ 35 ]. These findings suggest that subjective memory complaints can be reduced by identifying adults with SCD in community and primary care settings, adopting tailored exercise programs and appropriately adding a resistance exercise portion.…”