Higher Midlife Activity Cuts Dementia Risk by 40%, Study Reveals

A recent study has found a significant link between increased physical activity during midlife and a reduced risk of dementia. The research, conducted by scientists at the Boston University School of Public Health, analyzed data from the Framingham Heart Study Offspring, revealing that individuals aged 45 to 64 who engaged in higher levels of physical activity had a 40% lower risk of developing all-cause dementia over a span of 26 years.

The study monitored over 4,300 participants who were free from dementia at the outset. Researchers tracked their physical activity levels across three distinct life stages: early adulthood, midlife, and late life. The average follow-up periods for these stages were 37.2 years, 25.9 years, and 14.5 years, respectively. Notably, those in the top two quintiles of midlife physical activity exhibited a dramatic decrease in dementia risk compared to those with the lowest activity levels.

According to study author Phillip Hwang, Ph.D., from the Department of Epidemiology, the findings suggest that physical activity may play a crucial role in delaying or preventing dementia. Hwang stated, “These results may help to inform more precise and effective strategies to prevent or delay the onset of dementia in later life, and support evidence that the benefits of physical activity on the brain may extend to earlier in life than previously thought.”

Despite these promising results, the study did not observe the same benefits in participants who engaged in higher physical activity late in life. Both carriers and non-carriers of the APOE4 gene showed reduced dementia risk among this group. Hwang pointed out, “There are several possible mechanisms through which physical activity is thought to lower the risk of dementia, such as improving brain structure and function, reducing inflammation, and exerting benefits on vascular function.”

The researchers acknowledged that further investigation is needed to determine if these mechanisms occur simultaneously throughout a person’s life or whether they develop at different stages. Dr. Cathryn Devons, M.D., a geriatric medicine specialist at Phelps Hospital Northwell Health, commented on the findings, noting that exercise can lower the risk of various health issues, including hypertension and stroke, which are known to contribute to cognitive decline.

While the study highlights a strong association between midlife physical activity and a lower risk of dementia, there are limitations. Hwang mentioned that physical activity levels were self-reported, which could affect the accuracy of the data. He cautioned, “While we can say from these results that higher levels of overall physical activity are associated with reduced dementia risk, these results cannot translate well to recommendations about specific exercise types.”

Additionally, the study did not establish a link between early adulthood physical activity and dementia risk, possibly due to the limited number of dementia cases in that age group. The authors noted, “We may have been underpowered to detect associations with early adult life physical activity due to the small number of dementia cases in this age group.”

Despite these limitations, the research supports the notion that increased physical activity can help lower the risk of dementia, reinforcing the importance of staying active throughout life. As society grapples with the increasing prevalence of dementia, findings like these underscore the value of promoting physical activity as a potential preventive measure.