Your workout routine during your 40s and beyond can affect your risk of cognitive decline, new research suggests.
How you move your body now could affect your brain down the line, according to a recent study out of Boston University.
The research, published in JAMA Network Open, discovered that high physical activity levels during your mid-40s onward may reduce your risk of developing dementia, including Alzheimer’s disease.
The Context
Exercise has been shown to have positive effects on brain health and cognition. The practice can release peripheral BDNF (a protein that supports the growth and maintenance of neurons), increase blood flow, and enhance cerebrovascular health, which in turn supports better cognitive function, memory, and efficiency of attentional and executive control processes, research suggests. Some research has found positive links between mid- or late-life physical activity and cognitive function, dementia risk, and brain structure or connectivity.
“Physical activity helps improve our brain structure and function and may also directly lower the amount of Alzheimer’s disease neuropathology, such as amyloid-beta and tau,” lead author Francesca Marino, a postdoctoral research associate at Boston University’s Chobanian and Avedisian School of Medicine, said in a press release. “It can also help lower inflammation and improve our cardiovascular health by lowering blood pressure or reducing the risk of diabetes, for example.”
If midlife physical inactivity were addressed, cases of dementia (neurological conditions that may affect the ability to think, remember, and reason) would decrease by about 2 percent, according to a 2024 report from the Lancet Commission on dementia prevention.
That said, previous studies have flaws, according to the Boston University researchers. Many rely on older adults recalling exercise levels from years past rather than reporting them in real-time, which could skew results, per the authors. To determine when, exactly, physical activity could have the greatest impact on dementia risk, the researchers needed to analyze data untainted by bias.
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The Details
The researchers analyzed the health and lifestyle data of more than 4,300 people from the Framingham Heart Study’s Offspring Cohort — a group of people aged 5 to 70 who had health examinations every four to eight years beginning in the early 1970s.
These participants, all of whom were dementia-free at baseline, were categorized into life stages: early adult life (ages 26 to 44), midlife (ages 45 to 64), and late-life (ages 65 to 88). The researchers also assigned the participants to one of five groups based on self-reported physical activity levels at the start of the study.
At the end of the data collection period, the authors looked at which participants had ultimately developed dementia and adjusted the findings for confounding variables like age, sex, education, smoking status, and conditions like hypertension and diabetes, among others.
The Key Findings
When you’re active — and how — does seem to matter for cognitive health. The folks with the highest levels of physical activity during midlife had a 41 percent lower risk of all-cause dementia than those with the lowest levels of physical activity. The results were similar for late-life; people with high exercise levels during this period had a 45 percent lower risk of dementia. In midlife, moderate- to vigorous-intensity exercise was also linked with a lower risk of dementia, though intensity didn’t affect risk in late-life.
Interestingly, activity during early adulthood didn’t appear to influence dementia risk in this study. This could be because dementia typically isn’t diagnosed until older age, and this study’s follow-up period may not have been long enough to get the full picture for this group, according to the investigation.
The Impact
These new findings affirm exercise’s position as a modifiable risk factor for dementia and the need to consider it in early public health interventions. “We know that increasing levels of physical activity may help to reduce dementia risk, and these results support evidence that the benefits of physical activity on the brain may extend to earlier in life than previously thought,” study senior and corresponding author Phillip Hwang, assistant professor of epidemiology, said in a press release.
The Expert Insight
Lead author Marino said in a press release: “While all physical activity is likely beneficial, we found that more vigorous physical activity had the strongest links with dementia risk. Taking the time to be physically active now, particularly through higher-intensity activities that raise your heart rate, may help lower your risk of dementia in older age.”
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The Caveat
While this investigation showed general ties between exercise levels at different life stages and dementia risk, the authors state that more specific research is needed. Rather than looking solely at baseline activity levels, future studies will need to dig into the impact of exercise duration, type, intensity, and timing, as well as changes in activity patterns, over time, according to Hwang.
There’s no reason to wait. Start sharpening your own cognitive functioning with these science-backed tips to improve brainspan.