Shift work was associated with significantly increased all-cause mortality (HR=1.52) and greater PhenoAge acceleration, with biological age acceleration statistically accounting for 6.18% of the shift work–mortality association.
Shift work was associated with significantly increased all-cause mortality after full adjustment.
Associations between shift work and CVD mortality and cancer mortality were not statistically significant.
Shift workers showed greater biological age acceleration as measured by PhenoAge.
PhenoAge acceleration statistically accounted for a small but measurable proportion of the association between shift work and all-cause mortality.
No statistically significant interactions were observed in subgroup analyses of all-cause mortality.
The study used a prospective cohort design with a nationally representative U.S. sample to examine shift work, biological aging, and mortality.
This research suggests that people who work non-daytime shifts — such as night, evening, or rotating schedules — face a meaningfully higher risk of dying from any cause compared to those who work standard daytime hours. In a study of nearly 7,500 U.S. adults followed for an average of almost 12 years, shift workers were about 52% more likely to die during the follow-up period after accounting for other health and lifestyle factors. However, the study did not find statistically significant differences in deaths specifically from heart disease or cancer. The study also found that shift workers showed signs of accelerated biological aging — meaning their bodies appeared biologically older than their actual age, as measured by a tool called PhenoAge, which uses routine blood test results to estimate biological age. Shift workers' biological age was, on average, about 0.39 years older than expected. This accelerated aging appeared to account for roughly 6% of the increased mortality risk associated with shift work, though the researchers caution that this does not prove biological aging is the direct cause of the higher death risk. This research matters because it adds to a growing body of evidence that working outside of normal daytime hours may have long-term health consequences, potentially including faster biological aging. The finding that biological age acceleration only explains a small fraction of the mortality risk suggests that other mechanisms — such as disrupted sleep, metabolic changes, or social factors — likely also play important roles. The study's nationally representative sample strengthens confidence that these findings reflect patterns across the broader U.S. adult population.
Wang R, Yuan K, Li T, Liu B, Bao W, Rong S. (2026). Shift work, accelerated biological aging and mortality risk in US adults: a national prospective cohort study.. International archives of occupational and environmental health. https://doi.org/10.1007/s00420-026-02233-3