Dementia: A specific type of computer-based “speed” brain training may lower the long-term risk of dementia in older adults, according to results from a large randomised trial that tracked participants for two decades, though independent experts say the headline figure should be interpreted carefully.
The study followed more than 2,800 adults aged 65 and older who were enrolled starting in the late 1990s and randomly assigned to one of three types of cognitive training: speed of processing, memory, or reasoning, or to a control group that received no training. Participants completed two one-hour sessions per week for five weeks, with additional “booster” sessions offered later. Total training time was under 24 hours.
Also Read | Study links weaker body-clock rhythms to higher dementia risk in older adults
After 20 years of follow-up, analysis of US Medicare claims found that participants who completed the speed training plus booster sessions were less likely to receive a dementia diagnosis, translating to an estimated 25% lower risk compared with the control group. The memory and reasoning programs did not show a statistically significant effect in the same analysis.
The speed training task is designed to sharpen rapid visual processing and attention, often described as identifying or clicking objects such as cars or road signs that flash briefly in different parts of a screen, including the periphery. Researchers said they do not yet know why this approach appeared to outperform memory- and reasoning-focused training, but suspect it may influence how efficiently networks in the brain communicate.
Outside experts urged caution about reading the results as a guarantee that “brain games” prevent dementia. A review of the statistical uncertainty around the estimate suggests the true effect could be smaller than the headline number, and critics noted limitations such as the strength of evidence relying heavily on a subgroup finding and questions about how representative the participants were of the wider older population.
Researchers also emphasised that the findings apply to this specific training approach and do not automatically validate other commercial brain-training apps. Still, they said the results add to growing interest in practical, scalable ways to reduce dementia risk later in life.
Dementia remains a major global health challenge: the World Health Organization estimates 57 million people were living with dementia worldwide in 2021, and describes it as the seventh leading cause of death globally.
