Quick Facts

• Mayo Clinic researchers developed a risk calculator that predicts dementia up to 10 years before symptoms using brain scans
• Brain amyloid levels detected on PET scans were the strongest predictor among all factors tested in 5,858 participants
• Women with high amyloid at age 75 face 84% lifetime risk of mild cognitive impairment versus 56% for men with low amyloid

Researchers at Mayo Clinic have created the first risk calculator that can predict dementia and mild cognitive impairment up to 10 years before symptoms appear. The tool uses brain scans to measure amyloid protein buildup, which proved to be the strongest predictor of cognitive decline.

The study, published in The Lancet Neurology, analyzed data from 5,858 participants tracked over two decades through the Mayo Clinic Study of Aging. During this period, researchers recorded 1,200 new cases of mild cognitive impairment, nearly 1,000 cases of dementia, and more than 2,600 deaths.

The prediction model combines four key factors: age, sex, APOE ε4 genetic risk, and brain amyloid levels detected on PET scans. Brain amyloid emerged as the most powerful predictor.

“What’s exciting now is that we’re looking even earlier — before symptoms begin — to see if we can predict who might be at greatest risk of developing cognitive problems in the future,” said lead author Dr. Clifford Jack Jr.

The results show dramatic differences in risk based on amyloid levels. Among 75-year-old APOE ε4 carriers, lifetime risk of mild cognitive impairment jumped from 56% with low amyloid to over 80% with high amyloid levels.

Women face higher lifetime risk than men across all categories. Female APOE ε4 carriers at age 75 with the highest amyloid levels (centiloid 100) had an 84% lifetime risk of developing mild cognitive impairment, compared to 77% for men with the same risk factors.

The research addresses a major challenge in Alzheimer’s studies. “We found that the incident rate of dementia was two times greater among the people who dropped out of the study than those who continued to participate,” said Terry Therneau, who led the statistical analysis. The Mayo team overcame this by tracking participants through medical records even after they stopped actively participating.

Dr. Ronald Petersen, the study director, compared the tool to cholesterol screening for heart disease. “This kind of risk estimate could eventually help people and their doctors decide when to begin therapy or make lifestyle changes that may delay the onset of symptoms.”

The timing proves significant as new FDA-approved drugs like Leqembi target brain amyloid to slow cognitive decline. However, the tool remains restricted to research use until treatments receive approval for people with biological signs of Alzheimer’s but no symptoms.

Nicole Avena, a researcher at Mount Sinai School of Medicine not involved in the study, called it “a major advance in predictive neuroscience and preventive medicine.”

Future versions may incorporate blood-based biomarkers to make testing more accessible than current PET scans, which cost thousands of dollars and require specialized facilities.

Read more: The #1 Predictor Of Cognitive Decline, Backed By 20 Years Of Data