These people filled out questionnaires about how much they sleep and how active they are — from sedentary to heavy activity. The study checked physical activity in three life stages: early adult (26–44), midlife (45–64), and late life (65–88), as reported by Fox News. Participants were followed for 37.2 years in early adulthood, 25.9 years in midlife, and 14.5 years in late life to see if they developed Alzheimer’s or other dementias.
Physical activity and dementia risk
People with high midlife physical activity had a 40% lower risk of dementia over 26 years compared to people with low activity. People with high late-life physical activity had a 36–45% lower dementia risk over 15 years.
Study author Phillip Hwang, Ph.D., said the findings may help create better strategies to “prevent or delay the onset of dementia” and show that exercise benefits the brain earlier in life than believed. “These results may help…” says Phillip Hwang, Fox News Digital. Higher activity in midlife lowered dementia risk only for people who do NOT carry the APOE4 gene, which raises Alzheimer’s risk. But higher activity in late life helped both APOE4 carriers and non-carriers.
Exercise benefits for brain health
Hwang said exercise may protect the brain by improving brain structure, lowering inflammation, and helping blood vessels work better (“There are several possible mechanisms…”. Physical activity may also reduce toxic beta-amyloid buildup, which is linked to Alzheimer’s. These effects may help build cognitive reserve, meaning the brain can handle aging better.
Researchers said they still need more studies to learn whether these protective effects happen at the same time or at different stages in life. Geriatric doctor Dr. Cathryn Devons, who was not part of the study, said exercise lowers risks of hypertension, stroke, vascular disease, high cholesterol and diabetes, which all affect brain circulation, as stated by Fox News. She added that exercise also reduces inflammation, which protects the brain. One major limitation is that physical activity was self-reported, meaning people may not always report accurately. Because of this, the results cannot tell which exact types of exercise are best. Early adulthood activity did not show a link to dementia risk. Researchers said they may not have seen early adult effects because there were too few dementia cases among younger people (“We may have been underpowered…”, as per the report by Fox News Digital. Dr. Devons said that even with limitations, this study supports the idea that exercise helps lower dementia risk.
FAQs
Q1. Does exercise in midlife reduce dementia risk?
Yes, the study says people who stay active in midlife can lower their dementia risk by about 40%.
Q2. Can exercise help even if someone has the APOE4 Alzheimer’s gene?
Yes, the study found late-life physical activity reduces dementia risk for both APOE4 carriers and non-carriers.