Diabetes shows up not only in the heart and kidneys but in blood signals tied to the brain, according to researchers at the University of California San Diego. In a study published April 23, 2026 in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, the team found that diabetes was associated with changes in measurable biological markers in the blood that are linked to Alzheimer's disease and to nerve cell damage among Latino adults.
The analysis drew on more than 6,000 middle-aged and older Latino adults living in several U.S. cities with large Latino populations, including San Diego, and formed part of a 15-year community health research project. Researchers looked at whether people who had diabetes, or who had higher long-term blood sugar levels, differed in these blood-based indicators of Alzheimer's-related processes and neuronal injury.
"Diabetes is usually discussed in terms of heart disease or kidney problems, but our findings show it may also be closely connected to changes in the brain," said Hector González, PhD, the study's corresponding author and a professor in the Department of Neurosciences at UC San Diego School of Medicine. He described the blood signals as early clues about processes that could eventually lead to Alzheimer's disease.
The practical significance lies in timing and access. Blood tests are far cheaper and easier to obtain than brain scans or spinal fluid sampling, which raises the possibility of spotting risk-related changes years before symptoms appear, particularly in communities that have been underrepresented in dementia research. The findings point to an association rather than proof that diabetes causes these brain changes, but they strengthen the case that metabolic health deserves a place in conversations about long-term dementia risk.