The market for brain training is large, and many programs promise to keep the mind sharp. However, solid research demonstrating a clear long-term effect has been lacking.
An American study published in the journal Alzheimer's and Dementia: Translational Research & Clinical Research followed more than 2,800 individuals over a period of 20 years.
Participants were 65 years or older when the trial began in the late 1990s.
According to Medical Xpress, the results show that one particular type of training was associated with a reduced risk of developing dementia.
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However, other experts caution that the figures should be interpreted carefully.
Rachel Richardson of the Cochrane Collaboration pointed out that there is considerable uncertainty in the calculations.
How the study was conducted
Participants were randomly assigned to four groups. Three groups each received a different type of brain training, while one group served as a control.
The training amounted to less than 24 hours in total, spread over several years.
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Researchers followed up with participants after five, ten, and 20 years and used Medicare data to determine who had received a dementia diagnosis.
The group that trained reaction speed had a 25 percent lower risk of dementia compared with the control group. The other two forms of training showed no clear effect.
Possible explanation
The training method that demonstrated an effect required participants to respond quickly to symbols such as cars and road signs that appeared in different locations on a computer screen.
Co-author Marilyn Albert of Johns Hopkins University considers the study to be methodologically robust and believes it offers insight into how the risk of dementia might be reduced.
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At the same time, she suggests that the training may influence neural connections in the brain.
By contrast, statistics professor Baptiste Leurent of University College London has emphasized that the study contains significant limitations and that further research is needed before firm conclusions can be drawn.
Sources: Medical Xpress, and Alzheimer's and Dementia: Translational Research & Clinical Research.
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