Younger generations are aging faster than their predecessors, and it may be linked to an increase in early cancer, a new study suggests.
have happened recently Rates of some cancers increase in adults under 50Which includes breast, colorectal, kidney and uterine cancer. a 2023 paper It turns out that early cancer diagnoses increased by 25% globally between 1990 and 2019, and scientists are still investigating why this happened.
“The trend of cancer increasing at younger ages is very real, and it is not simply due to more efficient diagnosis, or diagnosis at earlier stages,” he said. Dr. Jyoti Nangliaa hematologist and cancer researcher at the Wellcome Sanger Institute in the UK, who was not involved in the new study. “It is possible that we are being exposed to new cancer-causing risks [our] “Their defenses have been altered in some way,” he told Live Science in an email.
The new study, published June 22 in the journal naturopathySuggests that there may be a wide “gap” between the chronological ages of younger generations and their biological age – A measure of how quickly the body’s tissues and systems are aging compared to older generations. It appears that greater differences among young adults are associated with a higher risk of developing cancer early in life.
The new study can’t prove that rapid biological aging causes early cancer, but it does provide new clues for scientists trying to uncover what drives the worrisome trend.
“This is really a proof of concept,” said the study’s co-author. yin kaoa molecular and clinical epidemiologist at the University of Washington School of Medicine and the Siteman Cancer Center told Live Science.
On hidden trends in dense data
Chronological age is straightforward: it is the number of years that have passed since a person’s birth. However, “biological age” can vary greatly from person to person. This catch-all term describes a range of metrics, including markers in DNA and the bloodstream. These are often measured using “Aging clocks“The purpose of which is to determine whether the body is acting much older than its chronological age.
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Scientists have increasingly used these summary measures in an attempt to understand why some people are more at risk of age-related diseases than others. To investigate whether there might be a link between biological age and the increase in early cancer, the new study analyzed data from more than 150,000 adults in the UK Biobank, a long-running project that has been tracking the health of nearly half a million UK adults since the mid-2000s.
Participants provided blood samples, many of which had already been measured for markers used to track biological aging. The study authors plugged these results into PhenoAge, a statistical model that estimates the “age difference” of a person at a given chronological age. In essence, this model can compare snapshots of two 40-year-olds – one born in 1950 and the other in 1965 – and see whether their blood markers show they have the same biological age.
“The traditional approach to cancer is really focusing on individual risk factors”, such as a history of obesity or high intake of ultraprocessed foodsCao said. “We are testing whether we can take advantage of these large biobanks and potentially find some biological imprints as a potential reflection of multiple exposures that could be linked to cancer risk,” he said.
The analysis revealed a worrying pattern: UK Biobank participants born between 1965 and 1974 had a larger age difference than those born between 1950 and 1954 at the same chronological age. Based on PhenoAge’s metrics, the level of systemic aging in the younger group was about 0.23 standard deviations higher than in the older group—a slight shift toward older-looking biology.
The researchers applied the same approach to nearly 10,000 participants in the U.S. National Institutes of Health’s All of Us research program, another large biobank. There, they found a more pronounced pattern: The age difference for people born between 1990 and 1999 was about 0.92 standard deviations greater than for people born between 1965 and 1969.
The study found that another blood-based aging clock, called the Klemmera-Double method, showed broadly the same pattern as phenoage, although slightly weaker.
One type of cancer that is increasing in adults under 50 is breast cancer.
(Image credit: Kali9 via Getty Images)
Real trend or data mirage?
In the UK Biobank cohort, researchers found that participants with greater age differences were more likely to develop early-onset solid cancers, meaning cancerous tumors that appear in tissues, rather than “liquid” cancers present in bodily fluids. This link was strongest for lung, gastrointestinal and uterine cancers. This conclusion was based on the medical records of the patients.
When participants were divided into three groups based on their biological age, those in the highest group had about a 15% higher risk of early solid cancer than those in the lowest group.
To dig deeper, the authors used a different model that estimates biological aging at the level of specific organs and systems using patterns of proteins in the blood. In nearly 20,000 UK Biobank participants, they found that markers suggesting an “older than expected” immune system were associated with a higher risk of early-onset lung cancer. Similarly, markers suggesting older than expected adipose tissue were associated with a higher risk of early-onset colorectal cancer.
Does this mean that the younger generation is aging faster and this is increasing cancer? Maybe, but probably not – the study’s findings have important caveats.
Cao said the pattern will need to be confirmed in other datasets and populations. Biological aging tests, including PhenoAge, are also relatively new, and their implications are not fully understood. While they clearly capture something about health and risk at the population level, at the individual level, different biological age tests can give very different answers for the same person. This raises the question of what any one number actually means for individual health.
It may be that the differences uncovered by Fennoz between young and old people are related to how the test was originally calibrated, stephen burgessa professor of biostatistics at the University of Cambridge, who was not involved in the study, told Live Science in an email. To know whether this is the case, one will have to take a deeper look at how the PhenoAge score is calculated and see whether it might have confounded the assessment of the UK Biobank and All Us cohorts, he said.
Cao said that, while the PhenoAge score has been linked to mortality risk in a range of adults, the test “requires further validation” when it comes to assessing cancer risk.
Like any observational study using large databases, it’s hard to disentangle cause and effect, Nanglia said.
“The main issue of this paper is correlation versus causation,” he said. “Either way, it is useful – in the first, as a potential way of tracking population health and cancer risk, and in the second, as insight into the mechanisms that cause cancer.”
Cao hopes his team’s approach will serve as another useful tool to figure out why more young people are getting cancer. “Hopefully this is just a starting point,” Cao said.