New imaging evidence linking thymus health to survival, cancer risk and cardiovascular outcomes in adults suggests a long-overlooked immune organ may hold important clues to longevity.
Research: Effects on thymus health in adults. Image credit: Nerthuz / Shutterstock
In a recent study published in the journal natureA group of researchers used imaging data and large cohort data to investigate how thymic health influences mortality, cancer and cardiovascular disease outcomes in adults.
Thymus and immune aging process
What if a tiny organ that you don’t often notice could predict your lifespan? The thymus gland produces T cells (a type of immune cell), but it shrinks as you age, a process called thymic involution.
Traditionally, it was thought that the thymus gland ceases to function after childhood, but recent research suggests that the thymus gland is associated with the aging of the immune system and the development of chronic diseases as we age.
As the incidence of cancer, heart disease, and metabolic syndrome increases globally, understanding the mechanisms behind this decline may be essential for future population health. Further research is needed into how changes in the thymus affect long-term health and well-being.
Large-scale cohort imaging and AI analysis methods
Researchers conducted a large observational study using data from two established cohorts: the National Lung Screening Trial (NLST) and the Framingham Heart Study (FHS). 27,612 participants underwent computed tomography (CT).
Using these CT images, we built a deep learning (DL) model using convolutional neural networks and self-supervised learning to quantify overall thymic health from the image data.
Rather than directly measuring thymic function, this model predicted thymic status based on structural features that produced a continuous score (scaled from 0 to 100 for ease of interpretation) as an image-based proxy for thymic functional status.
Group classification was based on population percentile into low, average, and high thymic health categories. The project’s 12-year results for all-cause mortality, lung cancer incidence, and cardiovascular disease were statistically analyzed using Kaplan-Meier survival curves and Cox proportional hazards models, adjusting for age, sex, smoking status, pack-years, and body mass index (BMI).
Additional analysis of thymic health was performed by assessing associations with metabolic markers, lifestyle habits, and the presence of inflammatory proteins. With the aim of understanding the underlying biological mechanisms associated with thymic dysfunction, blood-based biomarkers such as C-reactive protein, cholesterol, and inflammatory cytokines such as interleukin-6 were measured.
Thymus health is associated with survival outcomes
The health status of the thymus gland varies greatly from person to person, even among people of the same age, highlighting the fact that immune aging is not uniform. Good thymic health was consistently associated with improved survival.
Based on this study, participants with healthy thymus glands were about half as likely to die from any cause over 12 years as participants with poor thymic health (13.4% vs. 25.5%), and the mortality rate remained substantial even after controlling for other risk factors such as smoking, age, and medical history.
Associations in the same direction were observed in FHS, but did not retain statistical significance even after full multivariate adjustment, resulting in partial but more limited replication between the two cohorts.
Reduce cancer risk by improving thymus function
Participants with good thymic health were observed to have a lower risk of developing lung cancer and lower lung cancer mortality rates. In one study, the incidence of lung cancer was reduced to 3.4% in a group with high thymic health compared to 5.3% in a group with low thymic health.
Deaths from lung cancer were reduced by almost half in people with good thymus function. These associations remained after adjusting for smoking-related variables, and although subgroup analyzes showed mixed rates depending on smoking status, these findings suggest that thymic health may contribute to cancer risk beyond traditional risk factors.
Cardiovascular benefits of a healthy thymus
People with better thymic health had significantly lower cardiovascular mortality, with up to a 63% risk reduction in the NLST and numerically significant reductions in the FHS, but statistically less strong. In addition, rates of heart attack and heart failure were also lower, although adjusting for age, sex, and smoking attenuated some associations, indicating more moderate or borderline effects on certain cardiovascular events.
Links on inflammation, lifestyle, and immune health
Beyond major illnesses, thymus health is related to overall health. Poor thymus health is associated with increased mortality from lung, metabolic, and gastrointestinal diseases. These findings suggest that the thymus influences overall resilience to multiple diseases rather than a single disease.
Lifestyle and metabolic factors are important for thymus health. Smoking damages the thymus gland, but metabolic health supports its function. Chronic inflammation can also compromise thymus health. Persistent elevated systemic inflammatory markers are associated with decreased thymic scores, indicating a link between immunosenescence and systemic inflammation associated with multiple chronic diseases.
Implications for longevity and disease prevention
This study shows that thymic health remains an important determinant of adult health, influencing survival, cancer risk, and cardiovascular outcomes. Historically, the thymus gland was thought to be largely inactive after childhood, but continues to support and maintain immune function throughout life. Importantly, thymus health varies widely from person to person and reflects each person’s unique lifestyle and metabolic factors.
Studies of the thymus have demonstrated that this gland may be a target for disease prevention strategies and longevity promotion. However, because this was an observational study, the results do not establish a causal relationship, and it remains unclear whether poor thymic health promotes disease risk or reflects an underlying decline in health.
Additionally, the study population was primarily Caucasian and included specific cohorts such as heavy smokers in the NLST, which may limit generalizability to the broader population. Differences in imaging protocols between cohorts mean that standardized clinical thresholds have not yet been established. Improving lifestyle behaviors, reducing inflammation, and maintaining immune function may work together to improve long-term health and quality of life.
Reference magazines:
- Barnats, S., Prudente, V., Pai, S., Atterman, A. K., Kao, Y., Chen, J., Rias, A., Foldina, B., Nürnberg, L., Bresem, K., Abosh, C., Swanton, C., Jamal Khanjani, M., Lu, MT, Murabito, J. M., Lunetta, K. L., Birkbach, N.J., Arts, HJWL. (2026). Effects on thymus health in adults. Nature. DOI: 10.1038/s41586-026-10242-y, https://www.nature.com/articles/s41586-026-10242-y
