Exercise and Brain Health: How Moving Your Body Lowers a Key Dementia Risk Marker

Dementia is now the leading cause of death in Australia (AIHW, 2024). While this statistic is sobering, research continues to show that lifestyle choices — particularly physical activity — can significantly reduce the risk of developing dementia. A new study from the University of Tasmania’s Wicking Dementia Research and Education Centre has revealed a biological link between exercise and reduced levels of a blood protein associated with brain inflammation. In short: moving your body really does help protect your brain.

What the Tasmanian study found

Researchers tapped into the ISLAND project, which follows Tasmanians aged over 50 to identify dementia risk factors. They looked at serum glial fibrillary acidic protein (GFAP) — a biomarker linked to neuroinflammation and brain health.

The study found that people who engaged in higher levels of physical activity had lower levels of GFAP in their blood (Roccati et al., 2024). Crucially, the relationship was strongest in those performing vigorous exercise — the kind that leaves you puffing, like running, swimming, or intense cycling.

Professor James Vickers, director of the Wicking Centre, explained that GFAP is “a good marker for general brain health” and that reducing it may signal better resilience against future dementia (Vickers, 2024).

Why GFAP matters

GFAP is a protein produced by astrocytes, the support cells of the brain. When the brain is under stress — through injury, inflammation, or early degenerative changes — GFAP levels rise. Elevated GFAP has been found in people at risk of Alzheimer’s disease, even before symptoms appear (Chatterjee et al., 2021).

So, lower GFAP levels in active people may reflect healthier brains and lower long-term risk.

What about genetics?The study also looked at the APOE ε4 gene, the strongest known genetic risk factor for Alzheimer’s. Around 25% of people carry one copy, while 2–3% carry two. For these individuals, the protective link between exercise and lower GFAP was weaker.

But here’s the important takeaway: genetics are not destiny. Even if someone carries APOE ε4, physical activity still provides benefits — just perhaps not as strongly reflected in GFAP (Roccati et al., 2024). As Dr Eddy Roccati noted, “You shouldn’t look at genes as determining your fate.”

Intensity matters

Moderate activity (like brisk walking) has benefits, but this study highlights that vigorous activity may give extra protection for the brain. That doesn’t mean everyone needs to start marathon training. Instead, it suggests including activities that make you sweat and breathe harder, as appropriate for your fitness and health status.

Examples include:

• Interval jogging or running

• Fast swimming

• Hill walking or stair climbing

• High-intensity cycling

Always check with your GP before starting vigorous exercise, especially if you have underlying health conditions.

Beyond exercise: 14 modifiable risk factors

Physical activity is just one piece of the puzzle. The Lancet Commission on dementia prevention, intervention and care lists 14 modifiable risk factors that, if addressed, could prevent up to 45% of dementia cases (Livingston et al., 2020). These include:

• Reducing blood pressure and cholesterol

• Treating hearing loss

• Improving sleep

• Managing obesity and diabetes

• Avoiding smoking

• Increasing social interaction

Together, these lifestyle changes help create a brain-healthy environment.

Why this matters for Australia

By 2065, almost 1.1 million Australians are predicted to be living with dementia — a 2.5-fold increase (AIHW, 2024). The findings from the ISLAND project highlight the urgent need for proactive prevention strategies.

Encouraging vigorous exercise in midlife may reduce future dementia cases and provide a measurable biological effect — lower GFAP — that could one day help track individual risk.

Key takeaway

Exercise isn’t just about muscles, weight, or heart health. It changes what’s happening inside your brain at a molecular level. Vigorous movement lowers a protein linked to brain inflammation and dementia risk. Whether it’s swimming, running, or dancing until you’re out of breath, your brain will thank you.

References 

• AIHW (2024) Dementia in Australia. Australian Institute of Health and Welfare. Available at: https://www.aihw.gov.au/reports/dementia/dementia-in-australia (Accessed: 22 September 2025).

• Chatterjee, P. et al. (2021) ‘Plasma glial fibrillary acidic protein is elevated in cognitively normal older adults at risk of Alzheimer’s disease’, Alzheimer’s Research & Therapy, 13, p. 59.

• Livingston, G. et al. (2020) ‘Dementia prevention, intervention, and care: 2020 report of the Lancet Commission’, The Lancet, 396(10248), pp. 413–446.

• Roccati, E., Vickers, J., and Wicking Dementia Research and Education Centre (2024) Physical activity and blood-based biomarkers of neurodegeneration in community dwelling Australians from ISLAND. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, 16(4), pp. e12422.

• Vickers, J. (2024) ABC News interview: Protein linked with brain inflammation reduced by exercise. ABC News, 20 September. Available at: https://www.abc.net.au/news/ (Accessed: 22 September 2025).