A simple blood test reveals the accelerated aging of organs decades in advance

Having lived a long time is the main risk factor for disease, but chronological age does not always tell us exactly how old we have become. Lifestyle and genetics can speed up or slow down the process, and medicine is researching ways to measure it accurately. Today, the journal Nature published the results of a study led by Tony Wyss-Coray, from Stanford University, in which researchers measured the specific aging of the body’s main organs to detect whether any are deteriorating at a faster rate than normal.

The system used is a blood test, which would make it relatively simple to employ to determine a person’s state of health. The study published today analyzed blood plasma from over 5,000 people and observed that around 20% of those over 50 years of age had one organ aging at an accelerated rate and 1.7% of study participants had two or more of them. This accelerated aging, which is partly associated with organ-specific diseases, is related to an increased risk of death of between 20% and 50%, but not all organs have the same impact on health. Accelerated aging of the heart increased heart failure by 250%, while faster deterioration of the vascular system and the brain were associated with a greater probability of suffering Alzheimer’s disease in the future, as researchers were able to verify with patient samples taken 15 years ago to monitor aging processes.

To assess the aging of the different organs, the researchers evaluated the levels of nearly 5,000 proteins in blood samples from almost 1,400 people, most of whom were over 40 years of age. They identified all the proteins that appeared most frequently in specific organs and selected 858 that could be associated with each organ and, when found in excessive levels, warned of that organ’s accelerated aging. Using machine learning, researchers trained an algorithm that selected the proteins most closely related to each organ’s aging. While the aging of each individual’s organs was somewhat in sync, as might be expected, there were also important differences that showed that some organs are particularly affected by the passage of time.

The goal of this type of work is to know well in advance that something is wrong with a particular organ so that preventive measures can be taken ahead of time. The test detected accelerated aging before there were symptoms, but, as the follow-up data showed, this faster aging increased the risk of disease and death in the future. The brain’s accelerated aging increased the risk of death by 180%, while accelerated aging of the kidneys was associated with an increased risk of diabetes and hypertension.

“This type of research creates the opportunity for us to precisely establish each organ’s rate of aging and thus its deterioration. With this [information], we could guide precise preventive medicine that would prescribe specific care and follow-up for each person based on observations of each organ’s biological age,” Manuel Collado, a CNB-CSIC scientific researcher at the Santiago de Compostela Institute of Public Health, told Spain’s Science Media Centre.

Around the world, researchers are investigating this potential tool for the precise diagnosis of accelerated aging. In April of this year, a team from the University of Melbourne in Australia published a study in Nature Medicine explaining how the accelerated aging of some organs eventually affects the aging of others and increases the risk of death. “Deviations from expected aging-related decline can be detected in certain organs (but not all) years before disease diagnosis,” they wrote. According to the authors, these deviations predict mortality, even when chronological age, disease burden, and other risk factors are taken into account, and they could be used to identify individuals with accelerated organ aging before the onset of disease who might benefit from interventions to slow the aging of specific organs or body systems.

Wyss-Coray, the author of the study published today in Nature, has spent more than a decade examining the blood for differences between young and old organisms. After observing that blood transfusions from young to old mice improved the functioning of many organs, including the brain, he founded Alkahest. Now owned by the Spanish pharmaceutical company Grifols, the company is testing the effects of transfusing plasma from young people into elderly Alzheimer’s patients. In regard to the latest results, Wyss-Coray believes that identifying the specific proteins in each organ that best predict accelerated aging can be used to create drugs that slow down the process.

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