In a recent systematic review (SR) and meta-analysis published in the journal Systematic Reviews, researchers investigated claims of the Chinese martial art Tai Chi delaying dementia progression and improving cognitive function in adults with mild cognitive impairment (MCI). They reviewed eight reviews and six randomized control trials (RCTs) and discovered a severe lack of formal Tai Chi research. While available evidence suggests that Tai Chi can benefit the physical and cognitive health of the elderly, most studies focus on healthy adults and present inconsistent findings.
Study: Effects and mechanisms of Tai Chi on mild cognitive impairment and early-stage dementia: a scoping review. Image Credit: Created with the assistance of DALL·E 3
Mechanisms underlying Tai Chi’s benefits were explored, with results revealing increased regional brain activity and regional grey matter volume. This SR highlights the need for further research before Tai Chi can be clinically recommended as an MCI intervention.
Tai Chi and mental health
Tai Chi is an internal Chinese martial art focusing more on spiritual, mental, and qi-related aspects than physical ones. Performed both for self-defense and its perceived health benefits, Tai Chi is growing in popularity worldwide as a form of gentle exercise and moving meditation. Unlike most other martial arts forms, Tai Chi intensity is low to moderate, comprising slow, flowing movements, allowing even older adults to practice the art easily.
Tai Chi is promoted as beneficial to physical and mental well-being, with anecdotal reports of its ability to slow the progression of mild cognitive impairment (MCI) and delay the onset of dementia. However, these claims have never been scientifically validated, with existing research presenting inconsistent, often contrasting results.
Dementia is a severe mental condition associated with numerous diseases wherein cognitive impairment significantly hampers physical and social functioning. It has no cure, with current clinical interventions aimed at delaying its onset and progression. Dementia is a silent global pandemic and a growing concern – the current prevalence is 55 million, with prevalence estimated to rise to 139 million by the year 2050. Dementia’s onset is preceded by MCI and is characterized by declining cognitive ability without significant reductions in daily functioning. MCI increases dementia risk by over five-fold and is, hence, the ideal stage for clinical intervention aimed at delaying dementia.
Some studies on the positive associations between Tai Chi and MCI have identified improvements in cognitive functioning, learning, memory, and visuospatial perception. Their results suggest that Tai Chi can act as a mind-body intervention, resulting in reduced fall risk, stress, depression, and dementia risk in MCI patients. More recent research, however, has challenged these findings, demonstrating no differences between MCI patients and healthy controls’ depression levels and executive functions following Tai Chi.
Moreover, the mechanisms underlying Tai Chi’s physical and neurological benefits remain unclear. Elucidating the benefits of Tai Chi would allow clinicians and researchers alike to recommend the art form as an inexpensive, non-pharmacological, side-effect-free intervention to combat dementia risk in the future.
About the study
In the present review, researchers aimed to investigate the psychological, neurocognitive, and physical effects of Tai Chi on MCI and early-stage dementia patients. They further sought to evaluate Tai Chi’s safety in these populations and unravel the neurological mechanisms of the art’s popularized benefits.
Data for this systematic review and meta-analysis was collated from multiple English and Chinese scientific databases. MEDLINE, PubMed, EMBASE, Cochrane Library, the Chinese Scientific Journal Database (VIP), the China National Knowledge Infrastructure (CNKI), the Wanfang Database, and Sino-Med were queried from their inception till 4 December 2020. Inclusion criteria comprised all studies conducted on adults over the age of 50 incorporating Tai Chi as an intervention, either independently or in combination with other interventions.
Data collected included bibliometric information, details of Tai Chi, participants’ anthropometric characteristics, case-control interventions, and study findings. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. It employed the A Measurement Tool to Assess Systematic Reviews (AMSTAR 2) software for review data quality appraisal. For randomized controlled trials (RCTs), the Cochrane risk of bias tool assessed quality.
No statistical analyses were carried out as a part of this review, and results were reported as a summary of key study findings. While a meta-analysis was initially proposed, insufficient qualitative studies made this unfeasible.
Study findings
The database search identified 1,157 potential records, but quality assessment narrowed this down to eight SRs and six RCTs for the effectiveness outcome, and five RCTs and four cross-sectional studies on Tai Chi’s mechanisms. The included studies comprised 5,054 individuals with study-specific sample sizes ranging from 11 to 1,061. Seven studies focused on MCI, while one focused on early-stage dementia. Study participants were between 55 and 85 years old. Four studies included Tai Chi along with a cohort of other interventions, while the remaining four evaluated Tai Chi independently.
Tai Chi interventions were between 30 to 120 minutes, one to six times per week, over eight to 52 weeks. The most commonly reported results included global cognition, memory, perceptual-motor, and executive functions. Two meta-analyses reported improved global cognition in the Tai Chi intervention group compared to controls, but two other meta-analyses failed to find differences between these cohorts.
Of the two meta-analyses exploring attention and executive function, one reported improvements associated with Tai Chi interventions, while the other was unable to find statistically significant differences between case (Tai Chi) and controls. Visuospatial effects of Tai Chi were found to be positive, but memory, language, and motor function results were either confounding between studies or inconclusive.
Tai Chi was found to have beneficial effects on the depression levels of patients with MCI, as measured by the Geriatric Depression Scale (GDS). Pain perception, especially in patients having arthritis as a comorbidity, was significantly improved in Tai Chi practitioners compared to controls. Similar improvements were reported for balance and reduced fall risk. Blood analyses revealed that Tai Chi practitioners had significantly higher plasma brain-derived neurotrophic factor (BDNF) levels than controls, but other cytokine and interleukin levels were indistinguishable from non-practitioners.
“Cornell Scale for Depression in Dementia (CSDD) scores lowered by 49% for the intervention group (p = 0.02) per-protocol analysis, which statistically signifies an improvement in depressive symptoms. After 1 year of practicing Tai Chi for at least 30 min per session and at least three sessions per week, Tai Chi was found to be superior to the control group (stretching and toning exercise) in slowing the progress of dementia as characterised by the DSM IV in people with amnestic MCI (p = 0.04).”
Conclusions
While there is some evidence for the beneficial effects of Tai Chi on neurological function and dementia risk reduction, current research remains inconclusive and, at times, even contradictory in its verdict with respect to Tai Chi as a clinically recommendable intervention to delay the progression of MCI to dementia.
More well-designed, large-scale, and transparently reported RCTs and meta-analyses for people with MCI or early-stage dementia are needed to inform clinical decision-making.
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