A study published June 22 in the journal Nature Medicine suggests that younger generations may have a wider gap between their chronological ages and their biological ages than older generations. This trend emerged from analysis of data from the UK Biobank and the U.S. National Institutes of Health's All of Us Research Program.

The study analyzed data from more than 150,000 adults in the UK Biobank. The study authors used PhenoAge, a statistical model that estimates a person's 'age gap' at a given chronological age, to analyze the data. UK Biobank participants born between 1965 and 1974 had a larger age gap than those born between 1950 and 1954 at the same chronological ages. Based on PhenoAge's metrics, the cohort born between 1965 and 1974 had systemic aging levels about 0.23 standard deviations higher than the cohort born between 1950 and 1954.

The researchers applied the same approach to about 10,000 participants in the U.S. National Institutes of Health's All of Us Research Program. In the All of Us Research Program data, people born between 1990 and 1999 had age gaps about 0.92 standard deviations higher than those born between 1965 and 1969. The Klemera-Doubal method, another blood-based aging clock, showed broadly similar patterns to PhenoAge, albeit slightly weaker ones.

In the UK Biobank cohort, participants with higher age gaps were more likely to develop early-onset solid cancers. The link between higher age gaps and early-onset solid cancers was strongest for lung, gastrointestinal, and uterine cancers. Participants in the highest biological age group had a roughly 15% higher risk of early-onset solid cancer than those in the lowest group. One 2023 paper suggests that early-onset cancer diagnoses rose by 25% globally between 1990 and 2019. Jyoti Nangalia, a hematologist and cancer researcher at the Wellcome Sanger Institute, stated, "The trend of increased cancers at younger ages is very real, and it is not simply because of more efficient diagnosis, or diagnosis at earlier stages."

There have been recent increases in the rates of breast, colorectal, kidney, and uterine cancers among adults under 50. Nangalia added, "It is possible that we are being exposed to new cancer-causing risks or that [our] defences to them are somehow altered." Yin Cao, a molecular and clinical epidemiologist at the Washington University School of Medicine and Siteman Cancer Center, said, "This is really proof-of-concept." Cao also said, "The traditional approach is really focusing on individual risk factors for cancer, such as a history of obesity or a high intake of ultraprocessed foods." She added, "We are testing whether we can leverage these large biobanks and potentially find some biological imprint as a potential reflection of many exposures that can be linked with cancer risk."

Why It Matters

The findings suggest a potential link between an accelerated biological aging process in younger generations and an increased risk of early-onset cancers. The observed correlations with early-onset cancers, particularly lung, gastrointestinal, and uterine cancers, indicate a possible underlying biological mechanism contributing to these health trends.