A recent study published in Nature reports that adults with a healthier thymus—a small immune organ—have a lower risk of death, cancer, and cardiovascular disease. The findings were released on Mar. 19 by researchers who used imaging data from two large cohorts: the National Lung Screening Trial (NLST) and the Framingham Heart Study (FHS).
The research is significant because it challenges the traditional view that the thymus becomes largely inactive after childhood. Instead, the study suggests that thymic health continues to influence immune function and resilience against chronic diseases throughout adulthood.
Researchers analyzed computed tomography (CT) scans from 27,612 participants to assess thymic health using a deep learning model. This model generated a score reflecting the structural features of each participant's thymus. Participants were then grouped into low, average, or high thymic health categories based on these scores.
Over a 12-year period, those with higher thymic health had about half the all-cause mortality rate compared to those with poor thymic health (13.4% versus 25.5%), even after adjusting for factors like age and smoking history. The study also found that individuals with better thymic health had lower rates of lung cancer incidence (3.4% versus 5.3%) and reduced deaths due to lung cancer. Cardiovascular mortality was up to 63% lower among those with high thymic health in one cohort.
The analysis further showed that lifestyle choices such as smoking negatively affect the thymus, while good metabolic health supports its function. Chronic inflammation was linked to poorer thymic scores, suggesting an association between immune aging and systemic inflammation.
While these results highlight the potential importance of maintaining a healthy thymus for longevity and disease prevention, researchers caution that their observational design does not prove causality. They also note limitations related to population diversity and differences in imaging protocols across cohorts.
