Mapping Healthy Aging: How India Is Building Its First Reference Standard ✎ medRxiv

In a room with a Siemens Magnetom Lumina scanner, a person lies motionless for 45 minutes while the magnetic field draws a map of their brain. Nearby, test tubes for blood, scissors for a lock of hair, and a laptop with memory tests wait their turn. This is how the assembly of the first atlas of healthy aging for an entire country begins in Hyderabad.

Participants are being recruited strictly: 300 healthy volunteers, 100 in each of the 19–35, 40–55, and 60–75 age groups, equally men and women. No chronic illnesses, long-term medication, or psychiatric diagnoses. Each person gives 8 mL of blood, a lock of hair from the crown, undergoes cognitive tests, and has a five-minute heart rhythm recording while seated. From the hair, chemists will extract cortisol, the stress hormone that accumulates there like tree rings in a trunk.

Blood is separated into plasma and cells, from which DNA and RNA will later be extracted. This will allow a look at chemical marks on genes and reveal which ones are active at different ages. MRI will measure cortical thickness and connections between brain regions. Together, molecules, images, tests, and pulse will add up to a multidimensional portrait of a healthy person.

Previously, research in India focused mainly on diseases: recruiting elderly people with dementia and looking for risk factors. Now, for the first time, a norm is being collected, starting from a young age, to see how a person changes throughout adult life. When the data are gathered by the end of 2026, doctors will be able to distinguish normal aging from the first warning signs of dementia in a specific patient. And policymakers will get a foundation for longevity programs based on local realities, not imported tables.