Thymus Gland Health May Be Key to Long Life and Fighting Cancer

Key TakeawaysAdults with healthy thymus glands show a 50% lower risk of premature death than those with poor thymic healthA strong thymus may help the body respond better to modern cancer treatments like immunotherapyChronic inflammation and lifestyle habits like smoking are linked to the premature shrinking and weakening of this organ.THURSDAY, March 19, 2026 (HealthDay News) — For decades, medical students were taught that the thymus — a small, butterfly-shaped gland in the upper chest — was essentially inactive once a person hit puberty. But new research suggests this overlooked organ may actually be a master switch for how well people age and survive life-threatening diseases.Researchers from Mass General Brigham in Boston used artificial intelligence (AI) to analyze more than 27,000 medical scans. They discovered that adults with a healthy, active thymus live longer and are significantly better at fighting off cancer and heart disease. The findings, published March 18 in two studies in the journal Nature, could change how doctors predict a patient's long-term health.The thymus serves as a training camp for T-cells, the elite soldiers of the immune system that identify and destroy infections and rogue cancer cells. It sits behind the chest bone just under the throat area. While the organ naturally shrinks as people age, the study found that the character and speed of this shrinking process vary widely between people. Researchers referred to this process as "thymic decay."“The thymus has been overlooked for decades and may be a missing piece in explaining why people age differently, and why cancer treatments fail in some patients,” said Hugo Aerts, director of the Artificial Intelligence in Medicine Program at Mass General Brigham.The two new studies relied on scans and other data collected during the National Lung Screening Trial and participants in the ongoing Framingham Heart Study.Using the scans, the AI model analyzed the size and composition of the thymus to give patients a thymic health score. It found that people with high, healthy thymic scores showed:A 50% lower risk of dying prematurely from any causeA 63% lower risk of death from heart-related issuesA 36% lower risk of developing lung cancerThe benefits extended into the doctor's office for those already fighting cancer. In the second study of 1,200 patients receiving immunotherapy, those with a robust thymus had a 37% lower risk of their cancer getting worse and a 44% lower risk of death.Researchers found that the thymus doesn't just fail on its own — lifestyle choices play a major role. Smoking, high body weight and constant inflammation were all tied to a weaker thymus.“Improving our understanding and monitoring of thymic health could eventually help physicians better assess disease risk and guide treatment decisions,” Aerts said.Researchers noted that their findings need to be confirmed in future studies. They also propose looking at whether changing lifestyle factors might improve thymic function and if therapies like radiation might affect the thymus health.More informationThe National Institute of Allergy and Infectious Diseases has more about how your immune system works and the organs that support it.SOURCES: Mass General Brigham, news release, March 18, 2026; Nature, March 18, 2026 .What This Means For YouHealthy lifestyle habits, such as not smoking and keeping weight in check, may keep your thymus gland healthier and protect your immune system's ability to fight off cancer and heart disease as you get older..Sign up for our weekly HealthDay newsletter

Thymus Gland Health May Be Key to Long Life and Fighting Cancer

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