Imagine if a single snapshot of your brain could whisper secrets about your future, how fast you’re aging, what illnesses might lie ahead, and whether there’s still time to change course. That’s exactly what scientists from Duke, Harvard, and the University of Otago have made possible.
Drawing on decades of data from the renowned Dunedin Study, these researchers have crafted a powerful tool, called DunedinPACNI, that reads the pace of aging from just one MRI scan. No need for years of tracking or invasive tests, just a quick look inside your head, and the story of your biological clock begins to unfold.
Even in midlife, while you still feel fine, this tool can spot early signs of decline, clues that chronic diseases might be waiting in the wings. That knowledge could be the nudge someone needs to eat better, move more, or sleep longer.
In older adults, the scan becomes a crystal ball. It can predict the likelihood of developing dementia or other age-related conditions years before symptoms show up—offering a precious window to intervene while there’s still time.
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For years, scientists have tried to build “aging clocks,” algorithms that estimate how fast someone is aging. But most of these clocks take a shortcut: they compare people of different ages at a single moment in time. That’s like guessing how fast a tree grows by looking at a forest snapshot, without knowing which trees started as saplings and which grew in harsher soil.
To overcome this, researchers turned to a rare scientific treasure: the Dunedin Study. Since the early 1970s, over 1,000 people born in Dunedin, New Zealand, have been tracked from birth through adulthood. Every few years, researchers measured their blood pressure, BMI, glucose, cholesterol, lung and kidney function, and even their gum health and tooth decay. This gave researchers a detailed, decades-long view of how each person’s body changed over time.
Using nearly 20 years of health data, the team created a personalized “rate of aging” score for each participant. Then they trained DunedinPACNI to predict that score using just one brain MRI taken at age 45. Next, they used it to analyze brain scans in other datasets from people in the U.K., the U.S., Canada, and Latin America.
The DunedinPACNI tool does more than track aging speed; it uncovers strong links between rapid aging and brain health:
- Faster agers scored lower on cognitive tests and showed quicker shrinkage in the hippocampus, the brain’s memory center.
- They faced a higher risk of cognitive decline with age.
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In a study of 624 adults aged 52–89:
- Those aging fastest were 60% more likely to develop dementia.
- They also experienced earlier memory and thinking problems.
The findings shocked researchers. Along with revealing the speed of brain aging, it paints a broader picture of your overall health and future risks.
People aging faster were more frail and more likely to suffer from heart attacks, lung disease, strokes, and other chronic conditions. The fastest agers were:
- 18% more likely to be diagnosed with a chronic illness within a few years.
- 40% more likely to die in that same period compared to average agers.
The link between brain and body aging is “pretty compelling.” And the tool’s accuracy held up across diverse populations, suggesting it captures something universal about how we age.
With the global population over 65 expected to double by 2050, age-related diseases like dementia are set to surge. Alzheimer’s alone could cost the world over $9 trillion by mid-century, more than many other major diseases. Most Alzheimer’s drugs fail because they’re given too late, and the fact is drugs can’t resurrect a dying brain.
But DunedinPACNI could change that by identifying at-risk individuals before symptoms appear, opening the door to earlier, more effective interventions.
The tool could also help researchers understand how factors like poor sleep or mental health accelerate aging, and why some people age faster than others. While more work is needed to bring DunedinPACNI into clinical use, its potential to reshape how we detect and treat aging is profound.
More research is needed to advance DunedinPACNI from a research tool to something that has practical applications in healthcare. But in the meantime, the team hopes the tool will help researchers with access to brain MRI data measure aging rates in ways that aging clocks based on other biomarkers, such as blood tests, can’t.
Journal Reference:
- Whitman, E.T., Elliott, M.L., Knodt, A.R., et al. DunedinPACNI estimates the longitudinal pace of aging from a single brain image to track health and disease. Nat Aging (2025). DOI: 10.1038/s43587-025-00897-z
