August M
A simple brain-training exercise may offer long-term protection against dementia, according to new research that is reshaping how scientists think about cognitive ageing.
The findings suggest that relatively modest mental effort could have effects lasting far longer than expected, reports NBC News.
Strong evidence emerges
A large US study has found that older adults who completed a specific form of cognitive speed training had a significantly lower risk of developing Alzheimer’s disease and other dementias. The research, reported by NBC News, followed participants for up to 20 years.
The study is a long-term follow-up of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial and was published in the journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions.
A surprising result
Participants who completed up to 23 hours of speed-based cognitive training over three years were found to have a 25% lower risk of dementia compared with those who received no training. Earlier results had already shown benefits after 10 years, but the durability of the effect surprised researchers.
“It’s very surprising,” Marilyn Albert, director of the Johns Hopkins Alzheimer’s Disease Research Center, told NBC News. “It’s not at all what I would have expected.”
How the study worked
The NIH-funded trial enrolled nearly 3,000 adults aged 65 and older who had no significant cognitive impairment. Participants were randomly assigned to speed training, memory training, reasoning training or a control group.
Only those who completed speed training and additional booster sessions showed a reduced dementia risk. Researchers tracked diagnoses through Medicare records, grouping all forms of dementia into one category.
Why speed matters
Speed training focuses on rapidly processing visual information and making quick decisions. Experts say it relies on implicit learning, which involves unconscious skill-building and engages different brain systems than memorisation or logical reasoning.
“Once the brain rewires for these skills, the change is durable even without continued practice,” Harvard neurologist Dr Sanjula Singh told NBC News.
Not a cure-all
Experts caution that cognitive training is not a standalone solution. Alzheimer’s is complex, and no single intervention can prevent it entirely.
Still, neurologists say the findings offer the strongest evidence so far that targeted brain training can build long-lasting cognitive resilience.
Wider prevention picture
According to NBC News, nearly half of dementia cases could be delayed or reduced by addressing risk factors such as hearing loss, poor cardiovascular health, vision problems and lack of exercise.
Brain training, researchers say, may now belong on that list.
Sources: NBC News, Alzheimer’s & Dementia: Translational Research & Clinical Interventions, National Institutes of Health
