Could Your Thymus Be the Key to Fighting Cancer?

Your thymus is a thyme leaf-shaped double-lobed organ located in the center of your chest, directly beneath your breastbone at the level of your heart. It’s part of your lymphatic system. The outer layer is called the cortex and the inner area is called the medulla. The two types of cells that make up the thymus are:¹

• Reticular cells, a subtype of connective tissue
• Lymphocytes, a type of white blood cells responsible for the specificity of your adaptive immune responses. Lymphocytes include thymus-derived cells (T cells), thymus-independent lymphocytes (B cells) and natural killer cells (NK cells)

Your Thymus — The Key to Immune Health

The primary function of the thymus is to aid in the maturation process of T cells, which are in charge of determining your immune response to antigens. Immature T cells produced by the bone marrow first migrate into the cortex of the thymus. Once there, they begin to differentiate and mature into functional T cells, which are your body’s first line of defense against foreign invaders such as viruses.

The T cells either mature into helper T cells (CD4+) or NK cells (CD8+). T cells and B cells work synergistically to produce antibodies once a foreign pathogen has been detected. The lymphocytes reenter your bloodstream by migrating into the medulla, which has veins that connect it to the rest of the circulatory system.

As explained by Dr. J.E. Williams in an article² detailing the roles of your thymus, T cells are involved in all aspects of immunity, including:

Your Thymus Is Crucial for Cancer Prevention

Your thymus is also crucial for the prevention of cancer, which makes sense considering your immune system is the first line of defense not only for viral infections but also cancer.³

Recent research⁴ by scientists at Harvard and Massachusetts General Hospital bears this out, showing that patients who underwent thymectomy (surgical removal of the thymus) had a twofold higher risk of cancer five years post-surgery, and a nearly threefold higher risk of dying from any cause. As reported by the authors:⁵

“At 5 years after surgery, all-cause mortality was higher in the thymectomy group than in the control group (8.1% vs. 2.8%; relative risk, 2.9 …), as was the risk of cancer (7.4% vs. 3.7%; relative risk, 2.0 …).

Although the risk of autoimmune disease did not differ substantially between the groups in the overall primary cohort (relative risk, 1.1 … ), a difference was found when patients with preoperative infection, cancer, or autoimmune disease were excluded from the analysis (12.3% vs. 7.9%; relative risk, 1.5 …).

In an analysis involving all patients with more than 5 years of follow-up (with or without a matched control), all-cause mortality was higher in the thymectomy group than in the general U.S. population (9.0% vs. 5.2%), as was mortality due to cancer (2.3% vs. 1.5%).

In the subgroup of patients in whom T-cell production and plasma cytokine levels were measured … those who had undergone thymectomy had less new production of CD4+ [helper T cells] and CD8+ [killer] lymphocytes than controls … and higher levels of proinflammatory cytokines in the blood.”

According to Dr. David Scadden,⁶ who led the investigation, the magnitude of the cancer risk post-thymectomy was entirely unexpected. “The primary reason why the thymus has an impact on overall health seems to be as a way to protect against the development of cancer,” he told The Harvard Gazette.⁷

Routine Thymectomies Need To Be Reconsidered

For decades, scientists have believed the thymus was of little use in adulthood, as its size and activity dwindles right after puberty. While thymus cancer and myasthenia gravis (an autoimmune condition) are common causes for thymus removal, surgeons will often take it out during heart surgery as well.

Because of its location, it tends to get in the way when working on the heart, so removing it makes the surgeon’s job easier. However, these new findings suggest that might be a bad idea, as it can significantly raise the patient’s risk of cancer and premature death. As noted by Scadden, “This study demonstrates just how vital the thymus is to maintaining adult health.”

Other Substances Produced by Your Thymus

Your thymus also produces several other substances that are important for immune health, including cytokines, which play a crucial role in the regulation of your immune function. As explained by Williams:⁸

“… too many cytokines trigger an immune storm sparking a hyperactive response that can cause death. That was the case in the first SARS coronavirus infections. Patients were overwhelmed by the virus and their immune systems overly aggressive response.

Cytokine storms are common in older patients with COVID-19 coronaviral infections. But, a healthy, well-functioning thymus keeps the immune system in balance.”

Your thymus also produces:⁹

How’s Your Thymus Function?

There’s no direct way to assess the function of your thymus, but a T- and B-lymphocyte test can give you an idea. If one or both of these lymphocytes are low, your thymus is probably underperforming. Common symptoms of low thymus function include:¹⁰

• Heightened susceptibility to the common cold and influenza
• Persistent chronic illnesses with nonspecific symptomology
• Persistent fatigue or being easily fatigued
• Slow wound healing
• Signs of premature or accelerated aging

Considering the importance of your thymic function, it stands to reason you’d want to optimize it to the best of your ability. As noted by Williams:¹¹

“Even in healthy aging, the immune function deteriorates. That’s because, in humans, the thymus gland ages faster than the rest of the body. It reaches its peak during adolescence and begins to atrophy with a significant decrease in size and function by middle age. By 75 years, the thymus weighs only 1/6 of its maximum weight of 37 grams during youth.

Aging is inevitable and irreversible. Some age slower and live longer than others. But, sooner than later, everyone’s thymus shrinks. Declining thymus function with accompanying glandular atrophy contributes to susceptibility of infection, autoimmunity, and an increased risk for cancer.

We don’t know why the thymus gland atrophies at such an alarming rate, but aging researchers consider preventing thymic atrophy pivotal in prolonging health during aging. So, it makes sense to protect your thymus starting around 35 years. And, becoming very proactive by ages 45-55.”

How to Rejuvenate Your Thymus

So, how do you rejuvenate your thymus? Williams reviews several strategies that can support and restore its function, starting with a healthy diet and restorative sleep. You can find my latest recommendations on these topics in “A Surprising Reason Why You May Need More Carbs in Your Diet” and “Why Sleep Deprivation Is a Recipe for Ill Health.”

Other supportive strategies include the following. For additional recommendations and general dosage suggestions, see Williams’ article:¹²

Growth Hormone and IGF-1 Boosts Size and Function of Thymus

Williams also recommends supplementing with human growth hormone (HGH) and insulin-like growth factor 1 (IGF-1) to improve the size and function of your thymus.

I do not recommend supplements for this, as they tend to be extremely costly and can have adverse side effects. Instead, consider implementing lifestyle strategies that raise HGH and/or IGF-1 naturally, such as:

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