A recent study published in JAMA Network Open highlights a significant link between increased physical activity in midlife and late life and a reduced risk of developing dementia. Researchers from the Boston University School of Public Health analyzed data from over 4,300 participants in the Framingham Heart Study Offspring cohort, all of whom were initially free of dementia. The findings suggest that engaging in higher levels of physical activity can dramatically lower dementia risk, underscoring the importance of exercise for cognitive health.
The researchers monitored participants’ physical activity across three life stages: early adulthood (ages 26-44), midlife (ages 45-64), and late life (ages 65-88). They followed the participants for an extended period, with average tracking durations ranging from 14.5 to 37.2 years, allowing for meticulous observation of the onset of Alzheimer’s disease and other dementia forms. The results were particularly striking: individuals who maintained higher activity levels during midlife exhibited a 40% decrease in their risk of all-cause dementia over a 26-year period compared to those with the lowest activity levels.
Higher physical activity in late life was associated with even greater reductions in dementia risk, ranging from 36% to 45% over a 15-year period. These findings suggest that the protective effects of physical activity on brain health may extend further back in life than previously acknowledged, potentially informing future preventive strategies.
Study author Dr. Phillip Hwang stressed that the results could guide effective approaches to prevent or delay the onset of dementia. The data suggests that the benefits of physical activity for brain health may begin earlier in life than previously thought.
Several mechanisms may explain the connection between exercise and brain health. Physical activity is believed to enhance brain structure and function, reduce inflammation, and positively impact vascular health. Additionally, it may influence Alzheimer’s disease pathology by addressing the buildup of toxic beta-amyloid in the brain. These factors could contribute to increased cognitive reserve, potentially delaying cognitive decline in later life.
Interestingly, the study found that while midlife higher activity was only linked to lower dementia risk in individuals without the APOE4 gene variant, engaging in higher levels of physical activity during late life showed reduced dementia risk regardless of APOE4 status. This differentiation highlights the complex nature of genetic factors in cognitive health.
Expert in geriatric medicine, Dr. Cathryn Devons, noted that exercise reduces the risk of various conditions, including hypertension, stroke, vascular disease, and diabetes. These conditions can increase the likelihood of circulatory problems affecting the brain. Furthermore, exercise is known to lower inflammation, providing additional protection for brain health.
Despite the significant findings, the researchers acknowledged limitations, such as reliance on self-reported physical activity data. There was also a lack of association found with early adult physical activity, likely due to fewer dementia cases in that age group. Nevertheless, the overarching message strongly supports the notion that physical activity plays a crucial role in lowering dementia risk, emphasizing its importance for maintaining cognitive well-being throughout the lifespan.
In conclusion, the study reinforces the growing body of evidence advocating for the inclusion of regular physical activity as part of a comprehensive approach to enhancing cognitive health and preventing neurodegenerative diseases.
