Scientists at the Karolinska Institute have identified a molecule in the sugar family whose level in the blood can indicate a person’s risk of developing Alzheimer’s disease up to a decade before symptoms appear. This finding comes from a detailed study that adds a new dimension to how researchers understand early brain changes linked to the disease.
Alzheimer’s disease involves the progressive loss of neurons in the brain, driven by abnormal build ups of beta-amyloid and tau proteins. Earlier work by the same team linked tau levels to specific sugars, known as glycans, in individuals with the condition. Those earlier analyses relied on cerebrospinal fluid, a sample that is invasive to obtain and not ideal for routine screening in clinical practice.
In the new work, researchers demonstrated that certain concentrations of glycans in the bloodstream were associated with more than a twofold increase in the risk of developing Alzheimer’s disease. This suggests that a simple blood test could be used to gauge long-term risk long before cognitive decline begins. The test showed an accuracy around eight in ten, which is a meaningful level for a noninvasive screening tool and for guiding further monitoring or preventive strategies.
The study analyzed data from 233 participants who were tracked over a period of 17 years, providing a robust view of how early biological signals relate to later disease development. The length of follow-up strengthens confidence that the blood glycan pattern can serve as an early indicator rather than a late consequence of neurodegeneration.
Experts note that early intervention is increasingly recognized as critical in Alzheimer’s disease, as therapies tend to work best when started before extensive brain damage occurs. The discovery offers a potential route to identifying individuals at higher risk well before clinical symptoms emerge, enabling closer observation, lifestyle adjustments, and the possible timely use of preventive approaches in medical practice.