New blood test 'clocks' could predict Alzheimer’s symptom onset years in advance

• Researchers have developed a blood-based model that estimates when Alzheimer’s symptoms are likely to begin within a margin of about 3 to 4 years.
• The findings suggest a single blood test could act as a biological ‘clock’ helping identify individuals who are likely to develop cognitive symptoms within a specific time frame.
• If validated in broader populations, this approach could improve the design of prevention trials and support earlier, more personalized planning for people at risk of Alzheimer’s disease.

More than 7 million Americans are living with Alzheimer’s disease, and this number is projected to rise to nearly 13 million by 2050.

By this estimation, health and long-term care costs for Alzheimer’s and other forms of dementia are projected to reach nearly $1 trillion in 2050.

Predicting the onset of Alzheimer’s disease could be critically important for both clinical trials and practice, by offering a significant window for intervention.

Current methods to help predict Alzheimer’s onset typically include brain imaging scans or spinal fluid tests. However, these tests can be expensive and difficult to access.

Blood tests may offer a more feasible option as a predictive model, but historically have been less accurate than other options.

Now, a study published in Nature Medicine suggests that measuring a single blood sample for patterns of specific proteins may help to anticipate future symptom onset.