Researchers from the University of Alberta in Edmonton, Canada, claim dementia sufferers benefit greatly from regular exercise, demonstrating improvements in cognitive functioning and their ability to perform daily activities.
The review revisited the results of 16 previous trials that had tested 937 people to see if exercise improved cognition, activities of daily life, behavior, depression and mortality of older people with dementia.
The researchers also explored whether there was a benefit to family members or caregivers.
Dementia is an umbrella term that covers a range of cognitive disorders characterized by memory loss and changes in personality.
The Alzheimer's Association claims that about 5.2 million Americans are affected by dementia and that one in three senior Americans will die with some form of dementia.
The organization also points out that the number of sufferers will likely rise as the population of the US ages, with estimates of 7.1 million sufferers by the year 2025.
The researchers wanted to test the theory that exercise might be useful for dementia patients by either slowing the progression of the disease or helping to treat it.
They argue that by improving a patient's ability to carry out everyday tasks, such as getting up from a chair or walking a short distance, it will bring about positive changes on mental processes such as memory and attention, known collectively as cognitive functioning.
The investigators were also keen to establish whether there was any indirect benefit for carers or family members by reducing some of the burden of the disease.
'More evidence needed'
Dorothy Forbes, associate professor of nursing at the University of Alberta and researcher on the study, explains why it was important to revisit the 2008 Cochrane review:
"In our previous review, we were unable to draw any conclusions about the effectiveness of exercise in older people with dementia, due to a shortage of appropriate trials."
For this study, the results of which are published by the Cochrane Collaboration, they expanded their research to include an additional 12 trials. By drawing on the new trial results, they were able to see that exercise could improve both cognitive functioning and the ability to carry out simple tasks for dementia sufferers.
"Following this new review, we are now able to conclude that there is promising evidence for exercise programs improving cognition and the ability to carry out daily activities. However, we do still need to be cautious about how we interpret these findings."
However, the researchers caution that there were substantial differences among the results of the individual trials. And they did not find "enough" evidence to support the view that exercise would improve challenging behaviors or depression among the elderly dementia patients.
"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. We also need to understand what level and intensity of exercise is beneficial for someone with dementia."
She adds that if more evidence becomes available in future, it may help to address the question of whether exercise can help people with dementia remain at home for longer.
Previous research has shown that people who exercise during middle age have a significantly lower risk of developing dementia later in life.