Alzheimer’s disease (and dementia more broadly) are expected to be among the greatest challenges of 21st century healthcare. Some good news: in a recent study, Canadian researchers found that exercise may benefit older people with dementia by improving their cognitive functioning and ability to carry out everyday activities. 

Revisiting the Past

The new study, published in The Cochrane Library, and led by Dorothy Forbes, an Associate Professor of Nursing at the University of Alberta in Edmonton, Alberta, updates a previous review she carried out with colleagues in 2008. For that review, the team of researchers identified relevant trials from searches of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group, The Cochrane Library, MEDLINE, and other databases. At that time, though, only four trials on the effects of exercise in older people with dementia were available. The team decided the evidence was insufficient to determine the effectiveness of physical activity “in managing or improving cognition, function, behavior, depression, and mortality in people with dementia.”

When they revisited the topic for their current review, the team of researchers found much more information available to them. For instance, data from eight trials involving 329 people showed that exercise could improve cognitive functioning. At the same time, the team found six studies involving 289 people which provided data that showed how exercise improved the ability of older people with dementia to carry out daily activities, such as getting up from a chair or walking short distances. Despite the evidence, the researchers remain cautious. They also note that they failed to find enough information to determine whether exercise improved depression or quality of life.

"Clearly, further research is needed to be able to develop best practice guidelines to enable healthcare providers to advise people with dementia living at home or in institutions," Forbes stated in a press release. "We also need to understand what level and intensity of exercise is beneficial for someone with dementia." Despite the gaps, Forbes may take heart from the fact that new animal studies have already verified some of her findings.

Exercise & Progression of Dementia

In the meanwhile, Iranian researchers have confirmed the Canadian findings. Researchers from Isfahan University of Medical Sciences, Iran, chose to investigate the effects of exercise in retarding onset and progression of memory deficit in neurodegenerative disorders, including Alzheimer's disease. Specifically, they focused their investigation on the effects of treadmill running on memory function; before, after, and continually (before and after) the development of nucleus basalis magnocellularis (NBM) lesions. (Rats with such lesions are known to mimic the memory deficits of people with Alzheimer's disease.)

“Our results showed that treadmill running delays cognitive decline in the NBM-lesion rats, prevented memory deficit, and has advantageous effects on short-term, intermediate and long-term memory,” wrote the authors in their study. “Exercising on a regular basis may impede memory loss significantly, which may be attributed to specific molecular pathways in the brain.” In other words, exercise could stave off the memory loss associated with Alzeheimer's.

Dementia Basics

Dementia is associated with memory deficits, yet it also affects the brain in many different ways and may change an individual’s personality, mood, and behavior. In the coming decades, public health officials expect the number of people suffering from dementia to sharply rise. Worldwide, 35.6 million people currently have dementia while 7.7 million new cases arise every year. It is believed that Alzheimer's disease may contribute to as much as 70 percent of all cases.

Sources: Forbes D, Thiessen EJ, Blake CM, et al. Exercise programs for people with dementia. Cochrane Database of Systematic Reviews. 2013.

Hosseini N, Alaei H, Reisi P, Radahmadi M. The effect of treadmill running on memory before and after the NBM-lesion in rats. Journal of Bodywork and Movement Therapies. 2013.