In 2021, nearly 15% of adults in the United States had diabetes, with over 90% of them diagnosed with type 2 diabetes. As diabetes cases surge globally, projections by the International Diabetes Federation indicate a dramatic increase in prevalence over the next two decades. New research highlights concerning connections between type 2 diabetes and brain health, raising important questions about dementia risk and accelerated brain aging.

Two recent studies shed light on these issues, providing new insights into the effects of type 2 diabetes on cognitive function and offering hope for prevention through healthy lifestyle choices.

A1C Levels and Dementia Risk: A Key Indicator

A study published on August 2 in JAMA Network Open reveals a strong link between hemoglobin A1c (HbA1c) levels and the risk of developing dementia. HbA1c is a measure of average blood sugar levels over a three-month period, but this study used a measure called "HbA1c time in range" (TIR) to better assess how stable blood sugar levels are over time. The findings suggest that maintaining stable HbA1c levels in the target range may significantly lower the risk of Alzheimer's disease and related dementias (ADRD) in older adults.

The study, which tracked 374,021 veterans with diabetes over a decade, found that those who maintained at least 60% of their HbA1c levels within the target range had a lower risk of developing dementia. "Dementia risks were particularly increased when A1c levels were mostly below the target range," noted Dr. Paul R. Conlin, medical service chief for the VA Boston Healthcare System and professor at Harvard Medical School. This finding emphasizes the importance of consistent blood sugar control in preventing cognitive decline.

Type 2 Diabetes and Brain Aging: Can Lifestyle Choices Help?

A second study, published on August 28 in Diabetes Care, explores how type 2 diabetes and prediabetes affect brain aging. Using MRI brain scans from more than 31,000 participants in the UK Biobank, researchers found that prediabetes was associated with a brain age 0.5 years older than a person’s chronological age, while diabetes accelerated brain aging by 2.3 years.

However, the study offers hope. Participants who engaged in high levels of physical activity, abstained from smoking, and avoided heavy alcohol consumption showed a reduced gap between their brain age and chronological age. While the study did not establish a causal link, it reinforces the idea that healthy lifestyle choices can mitigate the impact of diabetes on brain health.

“This study provides really great targets for lifestyle interventions to promote brain health,” said Dr. Scott Kaiser, Director of Geriatric Cognitive Health for the Pacific Neuroscience Institute. “It’s not just important at an individual level, but at a population level as well.”

Lead author Abigail Dove, a PhD student at Karolinska Institutet, highlighted the public health significance of these findings. “Diabetes is a well-established risk factor for dementia, but the role of diabetes and prediabetes in early brain aging remains unclear. Understanding how to protect the brain health of people with diabetes as they grow older is crucial.”

Conclusion: Prevention and Management

These findings underscore the need for proactive management of type 2 diabetes to not only reduce the risk of complications like dementia but also protect brain health as people age. Stable blood sugar levels and healthy lifestyle choices are key factors in managing the disease and improving long-term outcomes. With the prevalence of diabetes on the rise, public health strategies aimed at promoting these interventions could make a substantial impact on reducing brain-related complications associated with the condition.