Exercise is known to be beneficial for many body systems, including neuroprotective effects that not only protect but improve memory and cognition. But can you be too old or frail to reap the benefits of the protective and cognitive stimulating effects of exercise?
We know that with regular exercise, people living with even severe levels of frailty can improve their physical performance and several components of their frailty. But less is known about the effect of exercise on cognition in older people. To this end, a new systematic review has been published which aims to analyze the effects of physical exercise on the cognition of older adults living in the community and living with frailty.
Cognitive frailty is not a new concept and is an integral part of the multisystem dysregulation of the frailty process, which is sustained by chronic low levels of inflammation and altered cellular processes that affect homeostasis. The determining factors for the characterization of cognitive fragility are related to deficits derived from physical frailty, social determinants of health, decrease in the level of physical activity, diet, reduction of
social contact and reduction of domestic activities and health practices.
The hypothesis is that only with the physical aspects of fragility, through the use of exercise, the process of cognitive fragility can be reversed and some studies have shown these effects. The difficulty is that these studies have been small-scale and therefore are not yet conclusive. There hasn’t even been a systematic review that focuses directly on this topic and this is where this systematic review comes into play.
This systematic review was previously registered in PROSPERO and the review protocol adhered to PRISMA. The search strategy is published in its entirety and the articles to be included in the review are searched in 9 databases. According to The Cochrane Collaboration and several other reviews, including more than 4-5 databases it probably does not alter the results of the systematic review, but the completeness of the authors is to be commended.
The search strategies for each database have been included in their entirety in the appendix and below is an example of the search used for the Cochrane database.
Final string: ((frailty OR “frail elderly”) AND elderly AND (exercise or rehabilitation) AND cognition) in the title Abstract keyword – (Word variations searched).
As with all systematic reviews adhering to PRISMA, there were two principal investigators who decided which articles to include in the review and a third to help reach consensus in case of disagreement on the inclusion of an article.
Study selection and eligibility criteria have been published in full. The review included only RCTs that used exercise as an intervention in community-living seniors over the age of 60 with proven frailty and cognitive impairment. The good news is that to be considered physical activity, the training protocol had to be planned, systematic, structured, intentional, involve repetitive movements and be supervised by a qualified professional. Too often, systematic reviews or research involving exercise do not adhere to the core principles of training, immediately limiting the certainty of results.
Looking at the exclusion criteria, it is interesting to see that studies using Tai Chi-based exercise were excluded from the review. Tai Chi is very popular with healthcare professionals working with older people due to its balancing benefits, but it has also been suggested to have protective effects on memory. That said, Tai Chi and similar yoga and dance-based exercise programs for seniors are often sub-therapeutic as they do not follow training principles or are not dosed at the right intensity on an individual basis. This is probably why this type of exercise has been ruled out.
It is also worth noting that research involving people living with neurodegenerative disorders was excluded from the review. This makes sense as they have underlying affective memory pathology (including Alzheimer’s dementia).