Five Weeks of Speed Training Cuts Dementia Risk by 25 Percent

A Modest Investment Yields Decades of Protection

The most astonishing finding isn't just that brain training can reduce dementia risk—it's how little training was needed to achieve such dramatic results. Adults who completed just five to six weeks of speed-of-processing training, along with follow-up booster sessions one to three years later, showed a 25% reduced risk of dementia up to 20 years later . The researchers called the modest amount of training "astonishing" , with participants investing a maximum of 22.5 hours over three years.

The findings come from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, which enrolled 2,802 adults beginning in 1998-99 and randomly assigned them to one of three cognitive training groups or to a control group . The study included nearly 3,000 participants ages 65 and older from six different geographical areas, with 25% being minorities, making the findings generalizable to the entire U.S. population .

After two decades, 105 out of 264 participants (40%) who completed speed training and booster sessions were diagnosed with dementia, compared to 239 out of 491 (49%) people in the control group—representing a 25% lower incidence in the speed training group .

Why Speed Training Succeeded Where Others Failed

The speed-of-processing training taught people to rapidly spot visual details on a computer screen and manage increasingly complex tasks in less time, similar to the thought process that happens when driving . The game shows users one of two vehicles in a desert, town, or farmland setting, then a Route 66 sign appears briefly along the periphery surrounded by distracting road signs, requiring players to click on the correct vehicle and sign location .

The speed training was particularly effective because it was adaptive—adjusting its level of challenge for each participant's individual performance, with faster participants moving to quicker challenges while others started at slower levels . The memory and reasoning programs were not adaptive, with everyone learning the same strategies, and speed training drives implicit learning while memory and reasoning training drive explicit learning .

Crucially, the 25% reduction in dementia risk was only seen in people who had both the original speed training and the booster sessions—those without boosters didn't benefit . While the study tested three interventions focusing on memory, reasoning, or speed of processing, only the speed training made a statistically significant difference .

The Science Behind Long-Term Protection

Researchers believe speed training may cause physical changes to the brain, leading to new and stronger connections between brain networks . The speed training regimen's tendency to engage automatic, unconscious thought rather than slower, deliberate thinking may be another potential driver for the delayed diagnosis .

Study participants ranged in age from 65 to 94 years at enrollment, with researchers finding no substantial reduction of training benefit with age, suggesting that training can be started at any time . The specific speed training used in the study is now available through the company BrainHQ .

While there are vast amounts of brain-training games and apps claiming to fight cognitive decline, this randomized controlled trial—considered the gold standard for medical research—provides the first clear documentation that at least some form of cognitive training can lower dementia risk .

Practical Implications and Future Directions

Researchers suggest the findings support developing cognitive training interventions for older adults, particularly those targeting visual processing and divided attention abilities, and that adding this training to lifestyle change interventions may delay dementia onset . The researchers suspect speed training may synergize with lifestyle interventions associated with lowered risk of cognitive decline, such as increased physical activity and improved diet .

Activities like learning a new instrument or playing pickleball can challenge the brain in similar ways to speed-of-processing training by building skills that become more automatic with practice . Experts recommend viewing brain training as part of a broader approach to brain health, paired with other evidence-based strategies like exercise, social engagement, and managing cardiovascular health .

The implications extend far beyond individual health choices. This research represents one of the first results from a large randomized, controlled trial to demonstrate that any intervention—whether cognitive training, brain games, physical exercise, diet, or drugs—can lower the incidence of Alzheimer's disease and related dementias . As researchers continue investigating the underlying mechanisms, this breakthrough opens new possibilities for preventing one of aging's most feared conditions through surprisingly simple interventions.