New research has found blood glucose levels even at the normal range can have a significant impact on brain atrophy in ageing.

Dr Erin Walsh, lead author and post-doctoral research fellow at ANU, said the impacts of blood glucose on the brain is not limited to people with type 2 diabetes.

"People without diabetes can still have high enough blood glucose levels to have a negative health impact," said Dr Walsh from the Centre for Research on Ageing, Health and Wellbeing (CRAHW) at ANU.

"People with diabetes can have lower blood glucose levels than you might expect due to successful glycaemic management with medication, diet and exercise.

"The research suggests that maintaining healthy blood glucose levels can help promote healthy brain ageing. If you don't have diabetes it's not too early and if you do have diabetes it's not too late."

Dr Walsh said people should consider adopting healthy lifestyle habits, such as regular exercise and healthy diets.

"Having a healthy lifestyle contributes to good glycaemic control without needing a diabetes diagnosis to spur them into adopting these good habits," she said.

"It helps to keep unhealthy highly processed and sugary foods to a minimum. Also, regular physical activity every day can help, even if it is just a going for walk."

The research is part of the "Too sweet for our own good: An investigation of the effects of higher plasma glucose on cerebral health" project led by Associate Professor Nicolas Cherbuin, which is part of the longitudinal PATH through life study led by Professor Kaarin Anstey at ANU.

"The work would not be possible without being able to longitudinally explore blood glucose in members of the general public," said Dr Walsh.

The research was published in the journal Diabetes and Metabolism.