Organ aging measured by blood test may help predict age-related diseases

Our organs age at different rates, and a blood test determining how much they've each aged could predict the risk of conditions like lung cancer and heart disease decades later, finds a new study led by University College London (UCL) researchers.

The findings, published in The Lancet Digital Health, show how accelerated aging in specific organs can predict not only diseases affecting that organ, but diseases across the rest of the body as well.

Our organs function as an integrated system, but they can age at different rates. Aging in particular organs can contribute to numerous aging-related diseases, so it's important for us to take care of all aspects of our health.

"We found that a quick and easy blood test can identify whether a specific organ is aging faster than expected. In years to come, blood tests like this could play a crucial role in preventing numerous diseases.

"I believe that in the future of healthcare, the prevention of age-related diseases could begin much earlier, prioritizing those who would benefit most and tailoring interventions to individual risk profiles."

Mika Kivimaki, Lead Author, Professor, UCL Faculty of Brain Sciences

The research team, led by scientists from UCL Brain Sciences, the UCL Institute of Healthy Ageing, Stanford University, Inserm, and the University of Helsinki, analysed data from participants from the British Whitehall II study, a longitudinal cohort study that has been running since 1985 and is now led by Professor Kivimaki as Director.

The researchers analysed blood samples collected in the late 1990s from over 6,200 middle-aged adults to determine the biological age of nine organs (heart, blood vessels, liver, immune system, pancreas, kidneys, lungs, intestines, and the brain) and for the entire body. They measured the gap between a person's chronological (actual) age, and the assessed biological age of each of their organs as determined by markers of aging specific to that organ, finding that organs often aged at different rates in the same person.

Participants' health status was tracked for 20 years through national health registries. By the end of the follow-up period, they were aged 65–89, and many had been diagnosed with at least one of the aging-related diseases investigated in this study.

Follow-up data revealed that accelerated organ aging predicted the risk of 30 different diseases over the next 20 years in initially healthy people. For instance, a heart that aged more rapidly predicted significantly increased risk of cardiovascular diseases, while people with accelerated lung ageing were predisposed to respiratory infections, chronic obstructive pulmonary disease (COPD), and lung cancer. 

Surprisingly, the highest risk of dementia was found in those whose immune system aged faster than usual – not in those whose brains aged more rapidly in midlife. The scientists say this result supports previous findings that people prone to severe infections are also at higher risk for dementia later in life. The finding also suggests that inflammatory processes may play a key role in the development of neurodegenerative diseases.

The researchers found that kidney health was particularly linked to other organs, as people with accelerated kidney aging were more likely to later develop vascular disease, type 2 diabetes, and liver diseases, while biological aging of nearly all organs predicted increased risk of kidney disease.

The researchers say that as our organs function in close coordination, accelerated aging in one organ can impair the function of others, which may explain why people with a rapidly aging organ were particularly prone to experiencing multiple age-related diseases across different organs.

For many years, blood biomarkers (measurable indicators of health) were measured individually, making the process costly and inefficient, especially when analyzing multiple markers. Over the past decade, technological advancements have progressed rapidly, and today, thousands of proteins can be measured simultaneously from a single blood sample.

Blood protein concentrations fluctuate in response to environmental factors, lifestyle, diseases, and medications. As a result, new proteomic (protein-based) analyses offer a valuable window into monitoring the pace of aging.

The researchers say their findings support a future shift in healthcare toward more personalised and effective disease prevention. With proteomic signatures of organ aging, risk of age-related diseases can be identified earlier, preventive measures can be targeted more effectively, and interventions can be tailored to each person's risk profile.

Professor Kivimaki added: "We hope our findings could contribute to new ways of helping people stay healthy for longer as they age. Blood tests may advise whether a person needs to take better care of a particular organ, and potentially provide an early-warning signal that they may be at risk of a particular disease."

This study was supported by Wellcome, the Medical Research Council, the US National Institutes of Health, and the Research Council of Finland.