Scientists discover a two-stage aging process that may cause cancer and arthritis

Scientists have proposed a new two-stage model of aging that may explain why diseases such as cancer, arthritis, and shingles often emerge decades after initial damage occurs. According to researchers from University College London and Queen Mary University of London, early-life damage from infections, injuries, or genetic mutations can remain hidden and controlled by the body for years. However, as the body ages and undergoes genetic and biological changes, its ability to contain this damage weakens, allowing these latent problems to develop into chronic diseases. The first stage of this aging process involves the accumulation of various forms of damage during youth and middle age, which the body typically manages to repair or suppress. The second stage occurs later in life when normal genetic activity shifts in ways that reduce the body’s resilience and repair mechanisms. This decline enables previously dormant or contained damage to manifest as illness. This model offers a new perspective on why many age-related diseases appear predominantly in older adults, despite their origins tracing back to much earlier in life. The review highlights several examples to illustrate this process. Dormant viruses like those causing shingles can reactivate when the immune system weakens with age. Similarly, injuries sustained earlier in life may contribute to osteoarthritis as aging tissues lose their ability to recover. Inherited genetic mutations may also remain silent for decades before increasing the risk of cancers or fibrotic diseases in later years. By integrating insights from evolutionary biology and biomedical research, the scientists suggest that aging is a multifactorial process driven by the interplay between early damage and late-life genetic changes. This two-stage model has important implications for understanding and potentially preventing age-related diseases. It suggests that interventions targeting early damage or supporting the body’s repair functions in later life could delay or reduce the onset of chronic illnesses. The findings encourage a shift in focus toward the lifelong accumulation and management of biological damage, rather than solely addressing symptoms that appear in old age.