High blood sugar impairs brain health even without diabetes
A groundbreaking study by Baycrest has revealed that elevated blood sugar levels may negatively impact brain health even in individuals without a diabetes diagnosis. While the relationship between blood sugar and brain health is well-established in people living with diabetes, this research is the first to explore this connection in individuals who are not diagnosed with the condition.
“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,” explained Dr. Jean Chen, senior author of 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 categorisation 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. Researchers examined data from 146 healthy adults aged 18 and older. For each participant, blood sugar levels were assessed alongside brain activity, measured through magnetic resonance imaging (MRI), and heart rate variability, analysed using electrocardiogram (ECG) readings.
Key Findings:
- Cognitive Networks Affected
Higher blood sugar levels were linked to reduced connectivity within brain networks essential for cognition, including memory, attention, and emotion regulation.
“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 also serves as Baycrest’s Canada Research Chair in Neuroimaging of Aging and Professor of Biomedical Physics at the University of Toronto. She added, “It’s also important to get regular checkups and to work with a healthcare provider, especially if you have been diagnosed with pre-diabetes.” - Stronger Effects in Older Adults
Although the negative impact of elevated blood sugar on brain networks was observed across all age groups, it was more pronounced in older adults, who generally exhibited higher blood sugar levels compared to younger participants. - Greater Vulnerability in Women
Women showed a stronger association between elevated blood sugar and brain network connectivity decline compared to men, highlighting potential sex-based differences in vulnerability. - Link to Heart Rate Variability
The research also uncovered a relationship between higher blood sugar and lower heart rate variability – the measure of beat-to-beat changes in heart rate. Lower heart rate variability is associated with poorer brain health, while higher variability has been linked to better cognitive outcomes in prior studies.
Future Directions:
The researchers noted that heart rate variability, unlike blood sugar, may be a more accessible target for intervention in non-diabetic individuals. Modifying heart rate variability could potentially offer a pathway to enhancing brain health without requiring substantial changes in blood sugar levels.
Study Details and Support:
This research utilised data from the Leipzig Study for Mind-Body-Emotion Interactions (LEMON) dataset. Funding for the study was provided by the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Council of Canada.
This work underscores the importance of proactive blood sugar management for maintaining brain health across the lifespan, even in those without diabetes. For individuals, adopting a healthy diet, staying physically active, and seeking regular medical assessments can be crucial steps toward safeguarding both physical and cognitive well-being.
