A new study has found that people diagnosed with type 2 diabetes at a younger age face a higher risk of developing dementia compared to those diagnosed later in life.
This risk is particularly high for individuals with obesity, according to findings published in PLOS ONE.
"Our research suggests that early-onset type 2 diabetes may have cognitive consequences, emphasizing the need for dementia prevention strategies that address both diabetes and obesity," said Xiang Qi, assistant professor at NYU Rory Meyers College of Nursing and the study's lead author.
Type 2 diabetes is a known risk factor for dementia, although the exact reasons are not fully understood.
Researchers believe that issues commonly linked to diabetes -- such as high blood sugar, insulin resistance, and inflammation -- may contribute to changes in the brain that lead to dementia.
While type 2 diabetes was once more common in older adults, it is now increasingly seen in younger individuals. Globally, one in five people with type 2 diabetes is under the age of 40.
To explore the link between the timing of diabetes diagnosis and dementia risk, researchers analyzed data from the Health and Retirement Study, which followed U.S. adults aged 50 and older from 2002 to 2016.
This analysis included 1,213 participants who had type 2 diabetes but no dementia when the study began. Over 14 years, 216 participants (17.8%) developed dementia.
The findings revealed that the earlier a person was diagnosed with type 2 diabetes, the higher their risk for dementia:
For every year earlier a person was diagnosed, their risk of developing dementia increased by 1.9%.
The study also found that obesity worsens the link between early diabetes diagnosis and dementia. Participants with obesity and a diabetes diagnosis before age 50 had the highest dementia risk in the study.
The findings suggest that addressing obesity through diet, exercise, or medication could help reduce dementia risk in younger people with diabetes.
"This study highlights the importance of the age of diabetes diagnosis and suggests that targeting obesity may play a crucial role in preventing dementia," said Bei Wu, senior author and professor of global health at NYU Meyers.
The study was supported by the National Institute on Aging and the National Institute on Minority Health and Health Disparities. Researchers hope these insights will lead to better strategies for preventing dementia.
If you care about dementia, please read studies about dietary strategies to ward off dementia, and how omega-3 fatty acids fuel your mind.
For more health information, please see recent studies about Choline deficiency linked to Alzheimer's disease, and what to eat (and avoid) for dementia prevention.