Blood sugar and brain health: how diabetes impacts the brain

Jan 14 2019

Dr Rachel Wong

Spikes and dips in blood sugar levels experienced in the daily management of diabetes can undermine mental abilities such as memory and attention span. While the link between diabetes and dementia risk is not new, researchers at the University of Newcastle’s Clinical Nutrition Research Centre have shown that, even among type-2 diabetics who are in control of their blood sugar levels, performance of complex mental tasks falls short of that in people without diabetes.

“When we looked at the ability of blood vessels to deliver nutrients and oxygen to the working brain, we saw a blunting of responsiveness in type-2 diabetes,” said Dr Rachel Wong, NHMRC-ARC Dementia Research Fellow. “The consequence of reduced blood flow to the brain during a mental task is poor mental performance”.

The diabetes-dementia link is based largely on data collected in type-2 diabetes, hence the team is keen to investigate whether this association also applies to type-1 diabetes. “The exposure to rises and falls of blood sugar levels in type-1 diabetes is much greater compared to type-2 diabetes. We expect that the damage to small blood vessels in the brain is more severe, but there is a lack of data on consequences for the health of the brain in adults with type-1 diabetes, especially as they age.”

“It is unclear just when the impact of type-1 diabetes on mental capacity becomes apparent,” said Peter Howe, Emeritus Professor of Nutrition Research. “Yet loss of mental capacity well before old age can adversely affect self-management of diabetes,” Professor Howe added.

“If we could detect these deficits early in the disease progression, patients and their health providers could aim to counteract the damage before it becomes irreversible.”

The team at the Clinical Nutrition Research Centre is looking to boost awareness of the importance of maintaining optimal brain health among those living with type-1 diabetes. “Importantly, the first step is to identify how early we can detect the relationship between poor blood flow in the brain and suboptimal mental performance,” Dr Wong said.

This study, in collaboration with colleagues at Curtin University who will assess markers of brain inflammation, is supported by a Hunter Medical Research Institute Project Grant. “We are looking for 30-80 year olds with type-1 diabetes diagnosed before 18 years of age to attend our clinic in Newcastle on two occasions for assessments.” The team is also recruiting adults of the same age who do not have diabetes to be in the control arm of the study.

Interested volunteers should contact the research team on 4921 6691 or email: for further information.

* HMRI partners with the University of Newcastle, Hunter New England Health and the community.