Baycrest study finds high blood sugar in healthy adults linked to lower brain activity

Toronto, ON, December 3, 2024 – A study by Baycrest found that high blood sugar may impair brain health even in people without diabetes. While the link between blood sugar and brain health is well documented in individuals living with diabetes, Baycrest is the first to examine this connection in people without this diagnosis.

“Our results show that even if someone does not have a diabetes diagnosis, their blood sugar may already be high enough to be negatively impacting their brain health,” said Dr. Jean Chen, senior author on the study and Senior Scientist at the Rotman Research Institute, part of the Baycrest Academy for Research and Education (BARE). “Blood sugar exists on a spectrum – it isn’t a black and white categorization of healthy or unhealthy.”

The study, titled “The associations among glycemic control, heart variability, and autonomic brain function in healthy individuals: Age- and sex-related differences,” was recently published in the journal Neurobiology of Aging and examined 146 healthy adults aged 18 and older. For each individual, researchers analyzed blood sugar, brain activity using magnetic resonance imaging (MRI) scans and heart rate variability through electrocardiogram (ECG) readings.

“The findings highlight the importance of managing your blood sugar through healthy diet and exercise, not only for your body but also for your brain,” said Dr. Chen, who is also Baycrest’s Canada Research Chair in Neuroimaging of Aging and Professor of Biomedical Physics at the University of Toronto. “It’s also important to get regular checkups and to work with a healthcare provider, especially if you have been diagnosed with pre-diabetes.

Main study findings

• Higher blood sugar was associated with decreased connection in brain networks. These networks play a crucial role in all aspects of cognition including memory, attention and emotion regulation.
• The effect was stronger in older adults, but it was present across all ages; older adults generally had higher blood sugar than younger adults.
• The effect was also stronger in women than in men.
• In addition, there was a link between higher blood sugar and lower heart rate variability – that is, the beat-to-beat change in an individual’s heart rate. Previous research indicates that higher heart-rate variability is associated with better brain health.

In future work, the researchers could further investigate how to improve brain function by changing heart-rate variability, which is an easier target for intervention than blood sugar, especially in non-diabetic individuals.

This study was conducted using data from the Leipzig Study for Mind-Body-Emotion Interactions (LEMON) dataset. It was funded by the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Council of Canada.

About Baycrest

At Baycrest, our vision is a world where every older person lives with purpose, fulfilment and dignity. Baycrest is a global leader in aging and brain health innovation, with over 105 years of expertise in seniors' care and cutting-edge research. Baycrest has been Designated with Exemplary Status by Accreditation Canada, and drives industry-leading care and safety outcomes. As the home of the Centre for Aging + Brain Health Innovation (CABHI) powered by Baycrest, the Baycrest Academy for Research and Education (BARE) and the Canadian Consortium on Neurodegeneration in Aging, Baycrest is at the forefront of dementia research. Affiliated with the University of Toronto, Baycrest's training programs shape the future of care globally, while Baycrest Global Solutions extends its expertise to senior living and healthcare internationally. For more information, visit: baycrest.org.

About the Rotman Research Institute, part of the Baycrest Academy for Research and Education

The Rotman Research Institute (RRI) is a preeminent international centre for the study of aging and human brain function. Through generous support from private donors and funding agencies, the RRI advances our understanding of human brain structure and function in critical areas of clinical, cognitive, and computational neuroscience, including perception, memory, language, attention and decision making. With a primary focus on aging and brain health, including Alzheimer’s and related dementias, research at the RRI and across the Baycrest campus promotes effective care and improved quality of life for older adults through research into age- and disease-related behavioural and neural changes.

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Media contact
Natasha Nacevski-Laird
Media Relations Specialist, Baycrest
Nnacevski-laird@baycrest.org