Cognitive training exercises - or mental exercise - may help prevent cognitive decline in healthy older adults, while evidence for the benefits of pharmacologic substances and exercise is weak, outlines a review published in CMAJ (Canadian Medical Association Journal).
Mild cognitive impairment (cognitive decline that is more than normal for someone of a specific age) affects 10%-25% of people over age 70. The annual rate of decline to dementia (which is cognitive decline in several areas along with some functional ability) is about 10%. With an aging population, it is estimated that the prevalence of dementia will double to more than 1 million Canadians over the next 25 years.
The authors reviewed 32 randomized controlled trials to provide the latest evidence for physicians and their patients to help manage cognitive decline.
There is no strong evidence for pharmacologic treatments such as ginkgo, dehydroepiandrosterone (DHEA), vitamins and other substances. Most studies on efficacy show no effect whereas estrogen therapy showed an increase in cognitive decline and dementia. Evidence for the benefits of physical exercise is also weak.
Mental exercise, however, showed benefits in the three clinical trials included in the review. This involved computerized training programs or intensive one-on-one personal cognitive training in memory, reasoning or speed of processing. In one trial, participants had significantly improved memory during 5-year follow-up periods. Another study showed an improvement in auditory memory and attention in a group of seniors who participated in a computerized cognitive training program.
"This review provides some evidence to help clinicians and their patients address what strategies might prevent cognitive decline," writes Dr. Raza Naqvi, Division of Geriatric Medicine, University of Toronto, with coauthors. "Future studies should address the impact of cognitive training on the prevention of cognitive decline, and we encourage researchers to consider easily accessible tools such as crossword puzzles and sudoku that have not been rigorously studied. The studies in this review that assessed cognitive exercises used exercises that were both labour- and resource-intensive, and thus may not be applicable to most patients."