Consider two 70-year-olds.
Cliff seems slightly confused and forgetful, and has difficulty following conversations and instructions. Roxanne is always alert and leads conversations, bringing up new topics and easily adding details to other's ideas. They are the same age, yet far apart in cognition. Researchers call the difference between age in years and age in behavior and physical condition the brain age gap, or BAG.
Researchers in China have identified a set of genes that play a role in whether someone is a Cliff or a Roxanne. It measures the difference between an individual's predicted age, derived from machine learning models trained on magnetic resonance imaging (MRI) data, and chronological age. The confused Cliff has a bigger BAG than the alert Roxanne.
To continue reading, go to DNA Science, where this post first appeared.