The review of previously published research finds no evidence that pharmaceutical drugs, or nutritional supplements including herbal products or vitamins help prevent cognitive decline in healthy older adults. However, there is some evidence that mental exercises, such as computerised memory training programs, might help, say the Canadian researchers behind the review.
Led by Dr Raza Naqvi from the University of Toronto, the team note that the issue of whether such products can help to prevent cognitive declines 'is of particular importance' given that mild impairment affects between 10% and 25% of people over age 70.
"This review provides some evidence to help clinicians and their patients address what strategies might prevent cognitive decline," said Naqvi, who's team found no strong evidence of benefit from pharmacologic drugs like cholinesterase, herbal supplements such as ginkgo, or vitamins such as B6 or omega-3 fatty acids.
Writing in the Canadian Medical Association Journal (CMAJ), the research team reviewed 32 randomised clinical trials involving about 25,000 patients. They found the strongest evidence lay in mental exercises such as computerised training programs or intensive one-on-one personal cognitive training in memory, reasoning, or speed of processing.
In addition, Naqvi and his colleagues noted that some studies on oestrogen indicated an increase in cognitive decline and dementia risk - while the evidence on the value of physical exercise, such as strength-training, was weak.
Source: Canadian Medical Association Journal
Published online ahead of print, doi: 10.1503/cmaj.121448
"Preventing cognitive decline in healthy older adults"
Authors:Raza Naqvi, Dan Liberman, Jarred Rosenberg, Jillian Alston, Sharon Straus