Landmark Study Finds Brain Training Can Slash Dementia Risk by 25%
A groundbreaking 20-year study has revealed that a specific type of brain training, performed for just over a month, could reduce the risk of developing dementia by as much as a quarter. With projections indicating that two million people in the UK alone will be living with dementia by 2050, this research offers a potentially powerful tool in the fight against the memory-robbing condition.
The Gold Standard Research and Its Participants
Conducted by researchers at Johns Hopkins University, the study involved over 2,000 participants aged 65 and older. Professor Marilyn Albert, the study's lead author and a neurobiologist, stated: 'There was a lot of skepticism about whether or not brain training interventions were beneficial, and to me, our study answers the question that they are.' She described the findings as a 'gold standard' that provides clear evidence on how to reduce dementia risk.
Participants were randomly assigned to one of three brain training interventions or a control group. They engaged in hour-long sessions twice a week for five weeks. The most effective intervention involved speed training using a computer-based task called Double Decision.
How the Speed Training Works
In the Double Decision task, participants are briefly shown a scene featuring a car and a road sign before they disappear from the screen. They must then recall which car appeared and where the sign was located. The task is adaptive, meaning it becomes progressively more difficult as performance improves. At the hardest level, distractions increase, cars become more similar, and backgrounds grow more complex, potentially leading to broader brain activation.
The other two groups participated in memory or reasoning training, focusing on verbal recall and problem-solving abilities. Approximately half of the participants received booster sessions—four additional hour-long training sessions at the end of the first year and another four around three years later.
Striking Results and Notable Limitations
After 20 years, the researchers found that those who completed the speed training with booster sessions had a 25% lower risk of dementia diagnosis compared to the control group. No other group, including those who did speed training without follow-up sessions, showed a significant change in dementia risk.
'The size of the effect is really quite astonishing,' Professor Albert remarked. 'The benefit of the booster sessions for the speed-training arm is notable. The usefulness of repetitive task training in neurorehabilitation is well established in other neurological conditions such as stroke.'
The team suggested that booster sessions may lead to better outcomes by adapting to participants' improving abilities, increasing task difficulty over time. They concluded: 'This may suggest that cognitive training needs to be repeated over time in a specific manner to reduce dementia risk.'
However, the study has limitations. Participants tended to be healthier as a group, which could bias results. Dr Baptiste Leurent, a professor of medical statistics at University College London, noted that the evidence is 'questionable' because primary analyses did not show significant differences in dementia risk between training groups and the control group. He emphasized that subgroup analyses alone are not strong enough to prove effectiveness.
Expert Reactions and the Global Dementia Crisis
Dr Susan Kohlhaas of Alzheimer’s Research UK welcomed the findings but cautioned: 'This research does not show that brain training can prevent dementia.' Diagnoses were based on health records rather than clinical testing, making it impossible to determine if training altered the underlying diseases causing dementia.
Both experts agreed that future research is needed to understand how this training works, who benefits most, and how it complements existing brain health strategies like physical activity, heart health management, and social connection.
The study emerges amid a growing dementia crisis. A new report by Alzheimer Europe estimates that dementia cases in Europe will increase by almost two-thirds over the next 25 years, largely driven by Alzheimer's disease. In the UK, dementia caused 2,500 excess deaths in England last year, highlighting the urgent need for effective interventions.
Last month, experts outlined 56 evidence-based recommendations to cut dementia risk, including better control of high blood pressure and stronger public health messaging. As cases rise, this study underscores the potential of targeted cognitive training to delay diagnosis and improve outcomes.
