Exercise can significantly improve memory and cognitive function in people with dementia, including Alzheimer’s disease and mild cognitive impairment, by promoting brain health at molecular, cellular, and structural levels. Physical activity stimulates changes in the brain’s memory centers, enhances gene expression related to learning, reduces harmful protein buildup, and can even slow cognitive decline.
Dementia, including Alzheimer’s disease, is characterized by progressive memory loss and cognitive impairment due to brain changes like amyloid plaque accumulation, hippocampal shrinkage, and disrupted neural pathways. Exercise acts as a powerful intervention by targeting these underlying mechanisms. For example, research using mouse models of Alzheimer’s disease shows that regular physical activity improves learning and memory by activating key cellular pathways in the hippocampus, the brain’s memory hub. Exercise enhances signaling through growth factors such as the Epidermal Growth Factor Receptor (EGFR) and insulin pathways, which are typically less active in dementia. These pathways support neuron survival, plasticity, and the brain’s ability to form new memories. Blocking these pathways negates exercise’s benefits, highlighting their importance. Additionally, exercise raises levels of heparin-binding EGF (HB-EGF), a growth factor that helps reduce amyloid deposits and improve memory, suggesting a direct molecular link between physical activity and brain repair processes.
Beyond molecular changes, exercise also induces structural improvements in the brain. Studies involving people with mild cognitive impairment—a precursor to dementia—demonstrate that exercise programs, including gamified or video game–style physical activities, can increase the volume of the hippocampus and improve the integrity of white matter, which facilitates communication between brain regions. These structural changes correlate with better cognitive performance, including improved recall and executive functions such as attention and planning. The combination of physical and cognitive challenges in these exercise programs appears particularly effective in slowing cognitive decline and enhancing brain plasticity.
Exercise also benefits brain health by improving blood flow, reducing inflammation, and promoting the growth of new neurons, a process called neurogenesis. For instance, aerobic activities like walking or running increase oxygen and nutrient delivery to the brain, supporting the health of neurons and glial cells. This improved circulation helps clear toxic proteins associated with Alzheimer’s disease during sleep, when the brain’s waste clearance system is most active. Regular physical activity also supports better sleep quality, which is crucial for memory consolidation and brain detoxification.
Clinical studies in humans reinforce these findings. People with mild cognitive impairment who engage in regular physical activity show improvements in memory and executive function, and their risk of progressing to dementia decreases. Walking about 3,800 steps daily can reduce dementia risk by 25%, while walking nearly 10,000 steps daily can reduce it by over 50%. These benefits are seen regardless of the initial state of brain health, indicating that it’s never too late to start exercising.
Exercise is also a safe and accessible intervention for vascular dementia, a form of dementia caused by reduced blood flow to the brain. Both voluntary running and treadmill exercise have been shown to improve cognition in vascular dementia by enhancing vascular health and brain function.
Large-scale lifestyle intervention trials combining exercise with diet and cognitive training have demonstrated even greater benefits. For example, participants in multi-domain programs that include physical activity show marked improvements in executive function, processing speed, and memory compared to those who do not engage in such interventions. These programs also reduce other health risks like stroke and hospitalizations, contributing to overall better brain and body health.
In summary, exercise improves memory in dementia through multiple pathways: it boosts brain cell function and gene expression, promotes neurogenesis and brain structure preservation, enhances blood flow and toxin clearance, and supports cognitive function. Whether through aerobic exercise, strength training, or engaging exergames, physical activity is a powerful tool to maintain and even improve memory and cognitive abilities in people affected by dementia.
