Exercise may lower dementia risk, study suggests

Vigorous physical activity lowers levels of a blood protein tied to dementia risk and brain inflammation, new research has found.

Almost 1.1m people are predicted to have dementia by 2065 – a 2.5-fold increase.

Scientists at the University of Tasmania’s Wicking Dementia Research and Education Centre reported that exercise reduces levels of GFAP (glial fibrillary acidic protein).

GFAP is linked with brain inflammation and is considered a marker of general brain health.

The more vigorous the activity, the stronger the effect.

Dr Eddy Roccati, senior research fellow at the centre, said: “The finding is really significant because it shows for the first time how a blood-based biomarker, that’s indicative of dementia risk, is associated with a really key and accessible modifiable risk factor.”

The research team studied blood samples and lifestyle surveys from Tasmania’s ISLAND project, which tracks dementia risk factors over time.

Participants give a blood sample every two years and complete lifestyle surveys.

Those who engaged in activities “that make you puff and pant” – such as running or swimming – showed the largest reductions in GFAP.

Professor James Vickers, the centre’s director, said: “We’ve basically found the more physical activity you do, the lower levels of this GFAP protein we find in your blood, which is probably indicating that you’re in a better state of brain health.”

The link between exercise and GFAP reduction was weaker in people carrying the ApoE4 gene.

Around 25 per cent of people carry one copy and two to three per cent carry two copies.

ApoE4 is the strongest known genetic risk factor for Alzheimer’s disease and dementia, though inheriting it does not mean a person will definitely develop the condition.

Actor Chris Hemsworth revealed three years ago that he had inherited the gene from both parents.

Dr Roccati said even though the effect was less strong for people with the gene, physical activity remained important.

The researcher explained: “You shouldn’t look at genes as determining your fate [you] should be like, ‘I’ve got this gene and now I am going to look at the best risk factors for me to address so I can reduce my risk of dementia over time.’”

Professor Vickers said having a greater understanding of how lifestyle influences blood biomarkers could help predict future brain health.

“If we could measure them [biomarkers] as early as possible we would have an idea that in 10 or 15 years’ time whether you’d be in a much higher risk of dementia.”