A recent study has found that young adults are undergoing accelerated biological ageing compared with previous generations, a factor that may help explain the rising incidence of cancer among people under 50. The research, published in Nature Medicine, examined blood samples and health data from 164,000 adults in the United Kingdom and the United States as part of an international effort to understand this troubling trend.

The study focused on markers of biological ageing—reflecting “wear and tear” such as inflammation and DNA damage—that progress faster in today's younger adults than in older generations at the same chronological age. Using an algorithm called PhenoAge, researchers measured biological age relative to calendar age to assess how internal bodily functions are changing over time.

Findings revealed that people currently in their 50s showed biological ageing approximately 23 percent faster during their 30s and 40s compared to the rate experienced by those now in their 70s. Importantly, individuals whose biological age exceeded their true age were found to have a greater risk of developing cancer before age 55. This accelerated ageing process is thought to result from factors such as unhealthy lifestyles, environmental pollutants, and other societal influences.

Since 1993, cancer diagnoses among under-50s in the UK have increased at twice the rate seen in older populations, with breast, bowel, and ovarian cancers notably more common in younger adults. The study estimates that around 10,000 additional cancer cases now occur annually among Britons under 50 compared with rates seen in the 1990s, a pattern mirrored internationally.

In Australia, recent national data indicate an 8 percent rise over the past decade in cancer rates among people in their 30s, increasing from 125 to 135 cases per 100,000 annually.

The research was conducted as part of Team Prospect, a global initiative supported by Cancer Research UK and the American National Cancer Institute’s Cancer Grand Challenges program. Yin Cao, a co-author from Washington University School of Medicine, explained that biological ageing encompasses molecular and cellular changes affecting immune response, tissue function, and overall cellular damage, processes that are occurring earlier in some younger individuals. Cao emphasized the project’s focus on understanding how environmental, lifestyle, and societal factors may become biologically embedded, potentially driving the earlier onset of cancer.

The findings underscore the importance of further investigation into the complex interactions between lifestyle, environment, and biology to address the increasing cancer burden among younger adults.