The World Alzheimer Report (2016) stated that approximately 47 million people suffer with dementia, worldwide.1 Furthermore, said statistic was predicted to increase in excess of 131 million by the year 2050, while the population of individuals aged 65 and older continue to rise across the world.1(1) In this author’s previous posts, nutritional and sleep hygiene interventions were covered both as causes, and solutions to, managing Alzheimer’s disease (AD). In the following sections, this author would like to cover how exercise can help manage, and possibly control, symptoms/underlying mechanisms behind AD.
Jia et al1(2) stated that lifestyle factors, such as inactivity, are modifiable and may affect the development and progression of AD. Considering that exercise is a low cost and low risk endeavour, such an intervention could prove useful as part of a larger more inclusive approach in managing AD.1(2) The researchers also indicated that several trials suggested that physical activity and exercise helped improve cognitive performance amongst individuals with cognitive impairment.1(2) However, said research trials lacked clarification on which combinations of frequency, intensity, time, and type of exercises proved most efficacious.1(2) As such, Jia et al1(2) conducted a meta-analysis whose goal was to elucidate the dose-response effects of physical activity on cognition of patients with AD.
The researchers chose studies based on the following inclusion criteria: subjects had to be diagnosed with AD, involved in an exercise-only intervention in the experimental group, included a non-diet, non-exercise control group, pre/post-intervention cognitive function measurements were reported with means, standard deviations of Mini-Mental State Examination (MMSE) for both exercise and control groups, and written in English or Chinese.1(2) After consideration of said inclusion criteria, 13 studies remained for the meta-analysis. The following will consider the studies and meta-analysis in greater detail.
Further analysis of the 13 studies indicated only one implemented a moderate-to-high intensity protocol, while the remaining studies employed moderate intensity physical activity/exercise.1(4) Furthermore, aerobic exercise was chosen by said 11 studies while all interventions were conducted at an average of 40 minutes per session, with ranges from 30-60 minute durations.1(4) The study interventions were conducted at least 1 hour a week while the length of whole study averaged 16 weeks, with ranges from 12-24 weeks.1(4) One study reported adverse effect and another study did intention-to-treat (ITT) analysis follow-up MMSE score 3months after the intervention.1(4) Finally, one study reported follow-up MMSE score 3months after the intervention.1(4)
The researchers determined that physical activity and exercise could help improve the cognition of elderly individuals with AD.1(13) Such was supported by intervention groups showing a statistically significant improvement in cognition of subjects measured via the MMSE score.1(4) Additionally, high frequency interventions did not necessarily induce greater effects on cognition functions compared to low frequency interventions; the researchers noted that they still needed to elucidate the threshold of exercise and physical activity which could exert a positive effect on cognition performance amongst individuals with AD.1(1) Finally, although robust evidence exists supporting the effects of exercise/physical activity on cognition of patients with AD, research has still not identified the mechanisms behind such changes.1(8)
In conclusion, 47 million people are suffering with dementia, worldwide. Furthermore, said statistic was predicted to increase in excess of 131 million by the year 2050, while the population of individuals aged 65 and older continue to rise across the world. In addition to optimal nutrition and sleep quality/duration, evidence strongly suggests that exercise, as little as 3 days a week for 30 minutes per session, can induce benefits upon cognition and overall brain health amongst individuals with AD. As such, it would be prudent to include such a low cost and low risk intervention among said population, as part of a larger and more inclusive intervention.
1. Jia RX, Liang JH, Wang YQ. Effects of physical activity and exercise on the cognitive function of patients with Alzheimer’s disease: A meta-analysis. BMC Geriatrics. 2019;19(1):1-14. doi:10.1186/s12877-019-1175-2.