Feeling age may align with reality as scientists unveil a blood test method gauging organ aging speed. Discrepancies pose health risks.Daniel Belsky, an epidemiologist, lauds the team's compelling findings on organ aging but urges cautious optimism, emphasizing the need for extensive clinical validation.Aging, a catalyst for major diseases, prompts the quest for better predictive measures beyond chronological age. Scientists explore biological age through DNA changes and gut microbe composition for enhanced disease risk assessment.
Tony Wyss-Coray, co-author of the study, notes that current approaches overlook varied organ aging rates. Traditional methods like tissue biopsies are often impractical and costly for individual organ analysis.Creating a practical measure of organ-specific aging, Wyss-Coray and team identified concentrated proteins in 11 major organs. Analyzing blood samples using machine learning produced unique protein signatures, enabling the determination of organ age, such as a 55-year-old heart or a 75-year-old liver.
Analyzing blood samples from over 5500 individuals in previous medical studies, the researchers tested organ aging rates. In this mostly older white adult group, approximately one-fifth exhibited a single organ significantly older than its chronological age, while nearly 2% displayed accelerated aging in two or more organs.
Specific health conditions correlated with accelerated aging in certain organs. For instance, individuals with hypertension or diabetes exhibited kidneys approximately 1 year older, on average. Alzheimer's disease was linked to accelerated aging across most studied organs, suggesting the brain's susceptibility to damage in other body parts, notes Wyss-Coray.
Long-term studies allowed researchers to assess if organ biological age predicted future health issues. Accelerated aging in any organ correlated with a higher risk of death over the subsequent 15 years, while specific diseases were tied to aging in particular organs. For example, an additional 4 years of heart age more than doubled the risk of heart failure, and older brain age was associated with an elevated likelihood of future cognitive decline.
A simplified organ aging measure could enable doctors to predict disease risks, possibly preventing them, suggests Wyss-Coray. As an inventor on a related patent, he notes its potential for clinical research, assessing the impact of drugs or lifestyle changes targeting aging-related illnesses.
Daniela Witten, a biostatistician at the University of Washington, questions the added value of the "organ age signature" compared to existing blood tests. She highlights uncertainty about the technique's generalizability beyond the specific cohorts in this study.
Luigi Ferrucci, scientific director of the National Institute on Aging, deems the work "interesting and sophisticated" but notes its reliance on snapshots over an extended period. Replicating patterns in data collected more frequently could enhance accuracy, making predictions about illness onset more applicable to clinical settings.
Wyss-Coray acknowledges the need for additional validation with larger, diverse cohorts. Plans include analyzing data from tens of thousands in the UK Biobank and replicating findings in mice. The aim is to delve into specific protein-organ aging links in greater detail.
