A significant, long-term study indicates that engaging in brain-training video games may provide protection against dementia for decades. Experts deem this the most compelling evidence to date that cognitive training can yield enduring alterations in brain function.

“This is quite unexpected,” remarked Marilyn Albert, director of the Alzheimer’s Disease Research Center at Johns Hopkins University. “It’s not at all what I anticipated.”

This groundbreaking study, published Monday in the journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions, follows the Advanced Cognitive Training for Independent and Vital Older Adults (ACTIVE) trial.

The researchers discovered that participants who engaged in up to 23 hours of a specialized cognitive training known as speed training over a three-year span exhibited a striking 25% decrease in the risk of developing Alzheimer’s disease and other forms of dementia during a follow-up period of 20 years.

This finding reinforces earlier research that indicated participants had a lower risk of dementia after 10 years.

The ACTIVE study was a comprehensive randomized controlled trial funded by the National Institutes of Health (NIH), involving around 3,000 participants aged 65 and older, hailing from six geographic regions and showing no prior major cognitive impairment. About 25% of participants were minorities, and the majority were women.

Women are especially vulnerable to Alzheimer’s disease, developing dementia at nearly double the rate of men.

Initially, study participants were assigned to train bi-weekly for 60 to 75 minutes per session for a maximum of 10 sessions over five weeks. Approximately half of each training group received an additional 23 hours of booster training over three years.

Researchers monitored medical records through Medicare to track dementia diagnoses in participants throughout the 20-year follow-up. Various forms of dementia, including Alzheimer’s disease, vascular dementia, and frontotemporal dementia, were aggregated into one category.

Participants who underwent speed training along with booster sessions exhibited a 25% lower risk of being diagnosed with dementia compared to the control group, while those who did not receive additional training showed no benefits.

“The findings suggest that a relatively small input of effort can yield substantial benefits over the long term,” stated Dr. Richard Isaacson, a preventive neurologist at the Neurodegenerative Disease Institute in Boca Raton, Florida, who was not involved in this study.

Dr. Thomas Wisniewski, chair of the Department of Cognitive Neurology at New York University Langone Health, praised the study results as “remarkable,” asserting this is the strongest evidence to support cognitive training’s efficacy.

“This is the first conclusive documentation in a randomized controlled trial indicating that some forms of cognitive training can diminish dementia risk,” added Wisniewski, who was also not involved in the study.

Participants were assigned to one of three cognitive training programs: speed training, memory training, and reasoning training, with a control group that received no training.

Dr. Sanjla Singh, a physician-scientist and lecturer in neurology at Harvard Medical School, explained that speed training focuses on enhancing the brain’s ability to process visual information quickly and effectively. This involves quickly identifying items on a screen and making corresponding decisions.

Albert compares this thought process to the situational awareness required when driving. “When we’re driving and must pay attention to multiple things happening around us, we need to discern what’s relevant and what’s not,” she elaborated.

In memory training, participants learned to memorize a series of words and strategies for retaining story details, such as creating mental images and associations.

Reasoning training involved exercises aimed at enhancing problem-solving skills based on identifiable patterns, such as recognizing sequences in letters or numbers.

However, no significant protective effect against dementia was observed in those who participated in memory and reasoning training alone.

Researchers remain uncertain about why speed training proved beneficial while the other forms did not; one theory relates to the distinction between implicit and explicit learning.

Implicit learning refers to acquiring unconscious habits and skills, like riding a bike. In contrast, explicit learning entails consciously memorizing facts, such as vocabulary from flashcards.

Albert noted that implicit and explicit learning processes engage different regions of the brain.

“Once the brain adapts to these skills, the changes can persist even without ongoing practice,” Singh remarked. “For example, a child can learn to ride a bike in around 10 hours, and that skill lasts a lifetime.”

Speed training is similarly thought to foster long-term alterations in the brain, a phenomenon defined by neuroplasticity—the brain’s capacity to adapt and reconfigure itself in response to lifelong learning.

Dr. Kellyanne Niotis, a preventive neurologist and clinical assistant professor of neurology at Weill Cornell Medical College, stated that speed training can significantly impact cognitive reserve—the brain’s ability to withstand dementia’s effects, which builds over time through various factors, including education, mentally engaging activities, and social engagement.

“We believe this visual processing speed training engages broader neural networks, thereby enhancing the brain’s resilience and cognitive reserve,” she explained.

Another hypothesis for the efficacy of speed training is its adaptive nature, meaning the difficulty escalates according to an individual’s performance. Those who initially excelled quickly progressed to more challenging tasks, a feature not seen in other forms of training.

Should I start speed training?

The speed training used in this study was devised by psychologists Carlene Ball and Daniel Loncar, with support from an NIH grant. This program has since been refined and is now available as a tool named “Double Decision” via BrainHQ, an online subscription platform.

Based on the study results, Albert recommends this training for individuals aged 65 and older, akin to the study’s demographic.

However, early signs of Alzheimer’s disease can reportedly emerge decades before onset, indicating that those in their 40s or 50s could also experience protective benefits. She cautioned against making early conclusions regarding the advantages for younger individuals.

Click here to play the free version of the Double Decision Brain Game.

While these trial results are promising, experts emphasize that Alzheimer’s disease and other types of dementia are multifaceted, and no singular solution exists.

“Every individual possesses a brain that can be at risk for Alzheimer’s disease, and it’s crucial to prioritize brain health,” Isaacson urged.

How to Lower Your Risk of Dementia

Approximately seven million people in the U.S. are affected by Alzheimer’s disease, with projections estimating this figure will nearly double to around 13 million by 2050.

Fortunately, various factors correlated with a decreased risk of developing dementia exist. In fact, one report suggests that nearly half of all dementia cases could be deferred or mitigated by addressing specific risk factors, according to the Lancet Commission Report 2024.

Niotis advises individuals to take the following steps:

• Ensure regular hearing assessments.
• Manage metabolic risk factors such as cholesterol, blood sugar, and blood pressure.
• Correct vision issues, as vision loss is a known risk factor for dementia.

Regular exercise enhances blood circulation and nourishes the brain. Isaacson may also suggest combining cognitive-stimulating activities with exercise, such as walking during meetings or engaging in cognitive training while using a stationary bike.

Emerging research also indicates that the shingles vaccine might protect the brain against cognitive decline.

A comprehensive study from 2025 published in Nature revealed that individuals vaccinated against shingles were 20% less likely to develop dementia over a seven-year follow-up period than those who were unvaccinated.