A new study led by researchers at Washington University School of Medicine in St. Louis provides evidence that younger generations are indeed aging faster biologically than their older counterparts. The causes remain under investigation around the world, including global efforts led by research members of Siteman Cancer Center, based at Barnes-Jewish Hospital and WashU Medicine, and Cancer Grand Challenges, a global initiative co-founded by the National Cancer Institute and Cancer Research U.K.; but importantly, the new research links this accelerated aging to an increased risk of early-onset cancers in younger generations. In general, early-onset cancers are those diagnosed at age 55 or younger.

The larger the gap between biological age — that is, how old our bodies appear to be — and chronological age — which is how many years we have actually lived — the higher the cancer risk, according to the researchers. They found that people in more recent birth cohorts had larger age gaps than those in older birth cohorts, which may help explain the rise in early-onset cancer in recent generations.

Their study also identified links between faster aging in particular organ systems and increased risks for certain cancers. For instance, an immune system that appears older than its actual age was associated with early-onset lung cancer. Similarly, fat tissue that appears older than its chronological age was associated with early-onset colorectal cancer.