Brain-training speed exercises linked to lower dementia risk in long trial

A 20-year randomized trial of 2,021 adults 65 and older found that only speed-focused, adaptive brain-training was associated with a lower rate of dementia, with a stronger effect among participants who received booster sessions; memory and reasoning drills showed no clear benefit.

Researchers followed a randomized trial that began in the late 1990s and tracked participants for about 20 years. At the start, 2,021 people ages 65 and older enrolled and were assigned to one of four groups. One group completed speed-of-processing training, two groups completed memory or reasoning exercises, and a comparison group received no cognitive training. Training sessions took place over several weeks and some participants later received booster sessions. Key findings: - 2,021 participants aged 65 and older were randomized into four groups: speed training, memory training, reasoning training, and a no-training comparison. - Training consisted of up to ten 60–75 minute sessions over five to six weeks, and some participants returned for up to four 75-minute booster sessions one to three years later. - Twenty years after the trial began, only the speed-training group showed a lower incidence of Alzheimer’s disease and dementia; the effect was stronger among those who received booster sessions. - Study co-author Marilyn Albert reported that participants receiving speed training plus boosters had a 25% lower risk of receiving a dementia diagnosis by the end of the trial. - Memory and reasoning training groups did not differ from the comparison group in dementia rates. - About one quarter of participants belonged to minority groups, which the authors say may improve generalizability. Summary: The trial indicates that adaptive, speed-focused cognitive exercises were associated with reduced dementia diagnoses over two decades, while memory and reasoning drills were not. Researchers say the next steps are to investigate biological mechanisms, including follow-up MRI studies in people and complementary animal experiments to explore how training might affect the brain.