The hidden link between diabetes and dementia—who’s most at risk?

Every choice you make today has an impact on your health tomorrow. From the foods you eat to the exercise you get, every decision builds toward our long-term well-being. A groundbreaking new study is now shedding light on the connection many of us might not have considered: the link between how we manage diabetes and our risk of cognitive decline later in life.New research presented at the 28th European Congress of Endocrinology in Prague found a concerning link between certain types of diabetes and dementia risk. The study findings published in the Diabetes, Obesity and Metabolism journal really challenge how we think about our metabolic health.For years, healthcare professionals have warned about the complications associated with diabetes - heart disease, kidney damage, and vision problems. However, now they have discovered the damage diabetes can do to the brain. In fact, no amount of supplements can bridge the damage you do to your metabolic health.The researchers have found that people with diabetes are at an increased risk of developing dementia. However, the risk differs depending on the type of diabetes you have. They found that insulin-dependent diabetes (both type 2 and type 1) carries a significantly higher risk. Specifically, these higher-risk individuals were over twice as likely to develop the neurological disease.The study findings also reveal that dementia risk is not the same for all types of diabetes, and future prevention strategies, such as continuous glucose monitoring, should be implemented in routine diabetes management.To understand the impact of diabetes on the brain, the researchers from Kyung Hee University Hospital at Gangdong and Samsung Medical Center examined over 1.3 million adults in South Korea. The individuals were aged 40 or older and without dementia. They were grouped according to their diabetes status: no diabetes, type 2 diabetes using oral anti-diabetic medications, type 2 diabetes using insulin, and type 1 diabetes. The researchers followed these individuals from 2013 to 2024, or until a diagnosis of dementia. What they found was striking. They found that individuals with diabetes had a higher risk of developing dementia compared to those without diabetes.People with type 2 diabetes taking oral anti-diabetic medications were almost 1.3 times more likely to develop dementia. The risk was higher, about 2.1 times, for those with type 2 diabetes taking insulin. The risk rate was 2.4 times higher in those with type 1 diabetes. They observed similar trends for Alzheimer’s disease and vascular dementia.The researchers were surprised by how the dementia risk varies depending on the type of diabetes. This is surprising because it suggests that not all types of diabetes carry the same risk, and that people with more intensive or insulin-dependent treatment may be particularly vulnerable to cognitive decline. Recognising diabetes as a potential risk factor for brain health and not just a metabolic condition could help identify a group of patients who may benefit from earlier monitoring for cognitive decline. Improving long-term glucose control and reducing large fluctuations in glucose levels could play a role in lowering dementia risk,” lead author Professor Ji Eun Jun from Kyung Hee University Hospital at Gangdong said in a release.“Our findings may be partly explained by recurrent hypoglycemia and greater glucose fluctuations in insulin-treated patients, we are planning further studies to better understand these mechanisms. Ultimately, we hope to identify high-risk patients and determine whether improving glucose stability can help prevent dementia,” Professor Jun added.The study findings are particularly significant, as previous research mostly looked at type 2 diabetes and found a higher risk of dementia. However, they have limited and inconsistent evidence for the dementia risk that type 1 diabetes individuals carry, mostly due to the smaller study population. “Our study adds new insight by directly comparing type 1 diabetes, type 2 diabetes, and treatment intensity within a large nationwide population,” Professor Jun concluded.These findings are a wake-up call for lifestyle changes.