On Dec. 9, 2024, neurologists at Fudan University in Shanghai, China have identified 13 proteins in the blood that predict how quickly or slowly a person’s brain ages compared with the rest of their body.

Their study using machine learning to analyse brain-imaging data from 10,949 people, the researchers created a model to calculate a person’s brain age, on the basis of features such as the brain’s volume, surface area and distribution of white matter. The authors then analysed thousands of scans alongside blood samples and found eight proteins that were associated with fast brain ageing, and five linked to slower brain ageing.

The researchers analysed levels of 2,922 proteins in blood samples from 4,696 people, more than half of whom were female, and compared them with the same people’s brain ages derived from the scans. They identified 13 proteins that seemed to be connected with large brain age gaps, some of which are known to be involved in movement, cognition and mental health.

One key protein was brevican (BCAN), which helps to form and maintain the network of molecules around cells and is involved in learning and memory. In a separate analysis, the authors found that changes in levels of a range of blood proteins peak at three chronological ages: 57, 70 and 78 years, with each of these ages marking a distinct phase of brain ageing. The study was published in Nature Aging.