Abstract and Introduction
Background and Objectives: Meditation and mind–body exercises are suggested to delay decline or enhance cognitive capabilities in older adults. However, their effectiveness remains uncertain. This study assessed the effectiveness of meditation and mind–body exercises to improve cognition in elderly people aged 60 years or above. Moderator variables were also explored.
Research Design and Methods: A databases search (MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane Library, Web of Science, CNKI, and Wangfang) was conducted from the first available date to January 10, 2018. Inclusion criteria include (a) human older adults aged 60 years or above, (b) meditation, Tai Chi, Qigong, or yoga intervention, (c) intervention should be structured, (d) inclusion of a control group, (e) at least one outcome measure of cognition was measured at baseline and post-training, and (f) peer-reviewed journal articles in English or Chinese.
Results: Forty-one studies (N = 3,551) were included in the meta-analysis. In general, meditation and mind–body exercises improve cognition in the elderly people (SMD = 0.34, 95% CI: 0.19 to 0.48), but the cognition-enhancing effects depend on the type of exercise. In addition, cognitive performance is only improved when the length of intervention is longer than 12 weeks, exercise frequency is 3–7 times/week, or duration of an exercise session is 45–60 min/session.
Discussion and Implications: This study suggests that meditation and mind–body exercises are effective to improve cognition of older adults aged 60 years or above, and exercise parameters should be considered for intervention planning.
The world population is aging. The proportion of older adults aged 60 years or above is expected to increase from 12% to 22% between the years 2015 and 2050 (World Health Organization, 2018). Normal aging is associated not only with reduced physical health but also with cognitive decline. Other than healthy aging, some older people may have some forms of dementia. It is estimated that 47 million people worldwide are having dementia, and 66 million people could be affected by the year 2030 (Prince et al., 2013). Given a large number of affected people and the great burden imposed on the health care system, a search for effective interventions to ameliorate cognitive decline or improve cognitive functions in the older population is of immense significance.
Older adults of different cognitive statuses can improve cognitive functions through exercise participation (Angevaren, Aufdemkampe, Verhaar, Aleman, & Vanhees, 2008; Groot et al., 2016). Although cognition is usually reduced in older adults, abundant research has demonstrated the malleability of elderly people's neural system, which enables them to acquire new skills or restore the affected capabilities (Cai, Chan, Yan, & Peng, 2014; Wu, Chan, & Yan, 2016). Behavioral and psychological interventions (including physical exercises and cognitively stimulating activities) are recommended for improving cognitive functions of older adults. The association between physical activity and reduced risks of cognitive disorders in older adults has been documented (Buchman, Boyle, Yu, Shah, Wilson, & Bennett, 2012). The benefits of physical activity on cognition are believed to be mediated by the promotion of neurogenesis, synaptogenesis, and capillarization (Colcombe & Kramer, 2003), and increases in brain-derived neurotrophic factor and insulin-like growth factors (Cotman, Berchtold, & Christie, 2007; Vaynman, Ying, & Gomez-Pinilla, 2004). These interacting factors are supposed to contribute to the neuroprotective effects of exercises on elderly people's cognition.
Besides traditional physical exercises, there is a growing number of research into the benefits of mind–body exercises over the past decades. They are usually performed at a slow pace and low intensity, and thus, are particularly suitable for older adults (Guo, Shi, Yu, & Qiu, 2016; Taylor-Piliae et al., 2010). Compared to physical exercises, mind–body exercises have a higher cognitive demand and emphasize cognitive well-being. It has been suggested that exercise interventions with a higher cognitive demand are particularly efficacious to slow down age-related cognitive decline (Raichlen & Alexander, 2017). A recent meta-analysis has also shown that a combination of physical and cognitive activities is ideal for treating or preventing cognitive decline in older adults (Gheysen et al., 2018). Tai Chi, Qigong, and yoga are prime examples of mind–body exercises. Tai Chi is a multicomponent exercise that trains exercisers' aerobic, anaerobic, and flexibility capacities. Qigong involves a set of static or dynamic exercises through coordinated breathing and physical movements to cultivate one's internal energy to achieve body healing, and Baduanjin is one of the most common forms of Qigong (Chen et al., 2013). Yoga originates from ancient India and includes practice of postures, breathing, and meditation to support optimal homeostasis. There is increasing evidence to show the efficacy of mind–body exercises to improve the cognitive functions of the elderly people (Gothe & McAuley, 2015; Wu, Wang, Burgess, & Wu, 2013).
Mind–body exercises usually include meditation as a part of training. Meditation involves various emotional and attentional regulatory strategies to achieve cognitive well-being and emotional balance (Lutz, Dunne, & Davidson, 2006). There is a growing body of literature to suggest that meditation may benefit the cognitive functions in older adults and those with neurodegenerative diseases (Newberg et al., 2014), possibly through enhancements of brain regions related to interoception and attention (Hölzel et al., 2008).
In this study, we investigated if meditation and mind–body exercises (meditation, Qigong, Tai Chi, yoga) benefit older adults' cognition via the meta-analytic approach. Further examinations will be conducted to compare their effectiveness. To improve prescription of meditation and mind–body exercises in the future, we also analyzed the exercise moderators associated with cognitive benefits in older adults. It was hypothesized that, relative to the control participants, older adults in meditation and mind–body exercises show cognitive improvement. As suggested in previous research, different types of exercise may have varying influences on different cognitive domains (Voss, Nagamatsu, Liu-Ambrose, & Kramer, 2011). We hypothesized that cognitive improvement depends on the type of exercise.
Gerontologist. 2019;59(6):e782-e790. © 2019 Oxford University Press