I did a lot of research while making a video on the subject and wanted to share.
The first Nature study analyzed CT scans from 27,000+ adults across two cohorts. People with healthier thymuses had ~50% lower mortality, 63% lower cardiovascular death, and 36% lower lung cancer risk — even after adjusting for age, sex, smoking, BMI, diabetes, and heart disease. Thymic health also tracked with metabolic markers: higher HDL was good, higher triglycerides/glucose/blood pressure/BMI/inflammation were all bad. Physical inactivity and smoking were both independently harmful.
The second Nature paper found cancer patients with healthier thymuses responded better to immunotherapy acr
