Physical activity can improve cognition in patients with Alzheimer’s disease: a systematic review and meta-analysis of randomized controlled trials

Abstract

Background/objectiveAlzheimer’s disease (AD) is mainly characterized by decline of cognitive functions such as memory and learning, which has a high prevalence and poor drug efficacy in treatment regimes. A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to evaluate the effectiveness of exercise on cognitive function in patients diagnosed with AD.MethodsThe bibliographic databases (PubMed, Cochrane Library and Embase, and Web of Science) and four Chinese databases (Wanfang data, CBM, CNKI, and VIP) were searched to identify RCTs published in any language between January 1, 1960, and January 1, 2018. Only peer-reviewed articles and RCTs were included. The collected data were analyzed by Review Manager (5.3).ResultsOverall, 869 patients diagnosed with AD were included from 13 RCTs. Patients in the intervention group received pure exercise interventions and a cognitive test. Although there was heterogeneity in intervention methods and cognitive measures among studies, meta-analysis (seven studies) supports positive effects of physical activity on cognitive function of patients with AD (mean difference [MD] =2.53, the 95% CI=0.84 to 4.22, test for overall effect: Z=2.93 [P=0.003]). Eight studies demonstrated that exercise improves cognitive function for individuals with AD. However, the remaining five studies did not display a beneficial effect of exercise on cognitive function in patients with AD.ConclusionThis meta-analysis and systematic review indicated that exercise intervention might improve the cognitive function of AD or slow down the decline of cognition; however, this relationship was not always true across studies. RCTs with clear intervention criteria, large samples, and long-term follow-up are needed in the future to demonstrate the benefits of exercise for cognitive function in AD patients.

Exercise and dementia: what should we be recommending?

“…in a narrative review on AD patients found that exercise may improve global functioning (in particular in the mild-moderate phase) but they could not conclude it definitely promotes a positive effect upon cognition, due to limitations of the tests of cognition used in the studies: nevertheless, they still recommend prescribing exercise to sedentary patients at the early stages to prevent cognitive deterioration. Similarly,Du et al's. (2018) review of AD patients suggests exercise may prevent cognitive deterioration, but RCT's with 'clear intervention criteria, large samples and long term follow up are needed' Brett et al (2016).…”

“…There seems to be growing evidence for a slowing in the decline of cognitive function with exercise interventions in people with dementia (Bowes et al, 2013;Brett et al, 2016;Cammisuli et al, 2018;Du et al, 2018;Groot et al, 2016;Hernandez et al, 2015), but that conclusion is not universal. Parks and Cohen (2019) only found evidence of an effect of exercise on cognition for those with mild dementia.…”

Bidirectional Communication Between Brain and Muscle

“…In persons with mild cognitive impairment there is an increase in brain activation after 12 weeks of training (9). Exercise increases mental performance and function in older persons (10)(11)(12)(13). Overall, exercise increases neurogenesis, neuronal maturation, angiogenesis, hippocampal volume and learning and memory in mice (14).…”

Effect of Voluntary and Forced Training with Royal Jelly Consumption on Learning and Spatial Memory of Rat Model of Alzheimer’s Disease

“…Today, experts believe that diet and medication alone are not enough to treat and control disorders in patients with AD, but exercise should also be added to the daily schedule of AD patients. Various studies have proven the positive effects of exercise on the improvement of learning (11,12), memory (7,12), and cognition (13) in AD. Considering that the available findings are contradictory on the effects of exercises and RJ on learning and memory, especially in AD, it is important to find the best training intensity and nutrition to progress learning and memory in patients with AD.…”