Scientists at the Mayo Clinic have developed a groundbreaking method to predict Alzheimer’s risk decades before symptoms appear. The new tool, published in The Lancet Neurology, uses brain scans and genetic data to estimate both a person’s 10-year and lifetime risk of developing cognitive decline. According to a press release, the research draws on decades of data from the Mayo Clinic Study of Aging, a long-running effort tracking thousands of residents over time.
Led by Dr. Clifford Jack Jr., a radiologist at Mayo Clinic in Rochester, Minnesota, the team analyzed brain scans, genetics, and medical records from over 5,800 adults to create this predictive model. The study highlights the early formation of two key proteins, amyloid and tau, which disrupt neuron communication and eventually lead to memory loss and cognitive problems linked to Alzheimer’s.
Using specialized brain imaging, researchers were able to gauge the ‘biological severity’ of Alzheimer’s in people who were still cognitively healthy. The results were expressed on a scale from 0 to 100, with higher numbers indicating significant amyloid buildup and a higher risk of cognitive decline. Dr. Ronald Petersen, a study co-author and director of the Mayo Clinic Study of Aging, noted that this risk estimate could help individuals and their doctors decide when to begin therapy or make lifestyle changes to potentially delay symptom onset, much like how cholesterol levels predict heart attack risk.
The scientists factored in age, sex, and the presence of the APOE ε4 gene, a genetic variant known to raise Alzheimer’s risk. They also used a powerful statistical technique to project the likelihood of each person developing mild cognitive impairment (MCI) and then dementia over time. Researchers found that higher amyloid levels correlated with a greater lifetime and 10-year risk of developing memory problems.
One 75-year-old woman in the study who carried the genetic variant and had high amyloid buildup faced over an 80% lifetime risk of developing MCI, a stage between normal aging and dementia that can allow for independent living. Women overall had a higher lifetime risk than men, and those with the gene were more likely to experience cognitive decline than those without it.
While the study has some limitations, including its focus on older white adults and the use of expensive brain scans not generally accessible to the public, the researchers emphasize that the tool is an important step toward personalized Alzheimer’s prevention. Future versions may include simple blood tests for amyloid or other biomarkers, making risk assessment more accessible without specialized brain scans.
The study was funded by the National Institute on Aging, the GHR Foundation, Gates Ventures, and the Alexander Family Foundation.