Newer generations biologically age faster than their elders at the same age — this is revealed by a study of more than 164,000 people published in Nature Medicine. And this accelerated aging is associated with a significantly higher risk of cancer before age 55, notably for lung, digestive system, and uterine cancers.
What you will learn
- How researchers measure biological aging using nine blood biomarkers
- What difference in the biological age gap was observed between generations in the United States and the United Kingdom
- Why this accelerated aging persists even after accounting for smoking, obesity, and genetics
An Elevated Cancer Risk Among the Young — and an Underlying Mechanism
For more than a decade, clinical data have signaled a troubling trend: certain cancers are rising among young adults. Colorectal, lung, uterine, and digestive tract cancers are increasingly affecting people under 55. A 2025 study even showed that Millennials faced a higher risk for certain cancers than the generation of their parents.
To understand this phenomenon, Yin Cao, a molecular epidemiologist at Washington University in St. Louis, and colleagues adopted an unusual approach: rather than examining a single exposure, they measured individuals’ biological aging — and compared this aging across generations.
PhenoAge: Measuring the Body’s True Age
Biological aging is not age in years, but the apparent state of the body revealed by measurable blood biomarkers. The tool used, PhenoAge, combines chronological age with nine biomarkers: C-reactive protein (an inflammation marker), glucose, creatinine, albumin, white blood cell count, and four other indicators.
From these measurements, researchers calculated an age-gap score for each participant — an estimate of the gap between apparent biological age and actual age.
Striking Figures
The study analyzed data from 154,169 adults in the UK Biobank and 10,262 participants in the American All of Us program, spread across several generations. The results are striking.
In the United Kingdom, people born between 1965 and 1974 exhibited an apparent biological age gap 23% higher than those born between 1950 and 1954 at the same age. In the United States, the gap was even more pronounced: those born between 1990 and 1999 showed a score 92% higher than those born between 1965 and 1969.
In other words, at the same chronological age, more recent generations appear biologically older than their elders were at the same life stage.
A Direct Link to Cancer Risk
In a subset of the data, researchers established a link between these accelerated aging scores and the risk of cancer before age 55. For each one-standard-deviation increase in the age-gap score, the risk of early-onset solid cancers rises by 8%. The strongest association concerns lung cancer, with a 57% increased risk.
This link persists even after accounting for smoking, obesity, telomere length, and genetic predisposition — suggesting that biological aging is an independent factor, not simply a reflection of other known risks.
Proteomic analyses reveal additional nuances: aging of the immune system is more strongly linked to early-onset lung cancer, while advanced aging of adipose tissue is more related to colorectal cancer.
A Pathway to Personalized Prevention
The researchers’ ambition is clear: identify high-risk young people while they are still healthy, so as to concentrate prevention and early screening efforts where they will be most effective. This work opens the path to personalized prevention based on individual biology rather than generic recommendations.
