A NEW blood test can measure how different parts of the body are ageing, offering a more detailed and personalised picture of health than conventional methods. Scientists say the approach could transform how doctors predict and manage age‑related diseases.
Beyond Chronological Age
For decades, scientists have known that ageing does not occur at the same speed across the body. While one organ may deteriorate rapidly, another might remain relatively resilient, influenced by lifestyle, genetics and environmental factors. Traditional biological age tests rely on epigenetic clocks, which estimate ageing through DNA patterns in the blood. However, these provide only a single number rather than system‑specific detail, leaving gaps in understanding individual health risks.
Tracking Ageing Across 11 Body Systems
In research published in Nature Ageing, scientists analysed health data from around 7,500 people, including blood tests, medical histories and physical measures such as grip strength. They identified biomarkers such as cholesterol and blood sugar that correlate with organ decline. Using machine learning to connect these findings with DNA methylation patterns, the team created the Systems Age test, which scores the ageing of 11 physiological systems, from the heart and lungs to the brain, immune system and metabolism. Validation across 8,000 additional samples showed that these system‑specific results outperformed older epigenetic clocks in predicting disease. For example, the Systems Age heart score proved more accurate than standard biological age measures at forecasting cardiovascular disease.
Implications for Personalised Medicine
The ability to profile ageing across individual systems could bring new opportunities for personalised care. People with the same overall biological age may show very different patterns of health risk, and doctors could target interventions more effectively. A faster‑ageing immune system, for instance, might call for strategies to strengthen immunity, while a high heart score may prompt cardiovascular monitoring or lifestyle changes. Researchers suggest this test could eventually be integrated into routine care to guide system‑specific treatments, making management of ageing more precise and proactive.
Reference
Sehgal R et al. Systems age: a single blood methylation test to quantify aging heterogeneity across 11 physiological systems. Nature Aging. 2025;DOI:10.1038/s43587-025-00958-3.
