A study presented at the Alzheimer’s Association International Conference (AAIC) 2026 in London is challenging conventional thinking about Alzheimer’s disease by suggesting that targeted brain-training exercises may do more than sharpen cognition—they may also influence biological markers associated with the disease itself.
The findings come from the ENACT (Elucidating the Necessary Active Components of Training) Study, a randomized controlled trial that found participants using a specialized cognitive training program showed significant improvements in blood biomarkers linked to Alzheimer’s disease risk. Specifically, researchers reported favourable changes in the Aβ42/Aβ40 beta-amyloid ratio, a widely used indicator associated with neurodegeneration and Alzheimer’s pathology.
The training intervention used in the study was BrainHQ, a digital cognitive-training platform developed by Posit Science. Researchers believe this is the first study to directly examine the relationship between brain training and beta-amyloid biomarkers.
Moving beyond the “plaque and tangles” model
For decades, Alzheimer’s research has largely focused on the accumulation of amyloid plaques and tau tangles in the brain. Billions of dollars have been invested in therapies aimed at removing these protein deposits, yet clinical outcomes have often fallen short of expectations.
The ENACT findings add weight to a growing debate over whether amyloid accumulation is a cause of Alzheimer’s disease or a downstream effect of broader biological changes. According to Posit Science CEO and neuroplasticity researcher Dr. Henry Mahncke, the latest findings fit into an emerging body of evidence suggesting that improving brain plasticity may influence the biological mechanisms underlying cognitive decline.
The study involved 53 participants who were randomly assigned either to BrainHQ’s speed-of-processing exercises or to a control group that played conventional computer games, including activities such as word-search puzzles. After 20 hours of training, researchers observed significant improvements in amyloid-related biomarkers among those completing the BrainHQ exercises. They also noted differences in responses between men and women, echoing observations seen with several Alzheimer’s therapies.
A third piece of the puzzle
The ENACT results do not stand alone. Earlier this year, researchers reported long-term findings from the landmark ACTIVE (Advanced Cognitive Training for Independent and Vital Elderly) Study, a National Institutes of Health-funded project involving more than 2,800 older adults. The 20-year follow-up found that individuals who completed a specific form of computerized speed-of-processing training experienced a 25 percent reduction in dementia diagnoses, including Alzheimer’s disease, compared with control participants.
Importantly, the intervention required only a modest amount of training. Participants completed several weeks of cognitive exercises, followed by occasional booster sessions over the subsequent three years. Researchers then tracked outcomes through Medicare records over a two-decade period. The findings attracted considerable attention because no previous randomized cognitive-training intervention had demonstrated a reduction in dementia incidence over such an extended timescale.
Canada’s contribution: the INHANCE study
Canada has played a significant role in the growing evidence base behind cognitive training and dementia prevention. Researchers at McGill University and the Montreal Neurological Institute-Hospital (The Neuro) recently led the INHANCE (Improving Neurological Health in Aging via Neuroplasticity-based Computerized Exercise) Study, which examined how cognitive training influences the brain’s cholinergic system.
The cholinergic system produces acetylcholine, a neurotransmitter often called the brain’s “pay attention” chemical because it plays key roles in memory, attention, decision-making and learning. Acetylcholine levels naturally decline with age and are known to fall sharply in Alzheimer’s disease.
Using advanced PET imaging, the McGill team found that 10 weeks of BrainHQ training increased cholinergic activity in older adults. The effect was so substantial that researchers described it as restoring cholinergic health to levels typically seen in someone approximately ten years younger.
For Canada, where more than 750,000 people are living with dementia and where an aging population is expected to drive further increases in cases over coming decades, such findings are especially relevant. Non-pharmaceutical interventions that can be delivered digitally could become an important component of broader dementia-prevention strategies.
Taken together, the ACTIVE, INHANCE and ENACT studies suggest a possible biological pathway linking cognitive training to brain health. Researchers speculate that strengthening neuroplasticity may improve cholinergic function, reduce inflammation and ultimately influence the disease-related processes associated with Alzheimer’s.
While the findings are promising, experts caution that larger clinical studies will be needed to confirm the effects on amyloid biomarkers and determine whether these biological changes translate into meaningful reductions in future dementia risk. The ENACT trial was relatively small, involving just 53 participants, and further validation will be essential.
Nevertheless, the emerging evidence is noteworthy because it suggests that the brain may be more modifiable than previously believed. Rather than focusing exclusively on removing amyloid plaques after disease processes have begun, researchers are increasingly exploring how targeted interventions might strengthen the brain’s resilience earlier in life.