Immunosenescence and Cancer

Larry A. Law

The word 'immunosenescence' is very intimidating just by itself. The word describes the process of how our immune system degrades with age. The organs of the lymphatic system, where so many of the immune system cells are created and housed, change in the elderly. That is why flu and COVID-19 respiratory illnesses dramatically affect older folks rather than the young. As people age, both adaptive and innate immune systems tend to lose efficacy over time, leading to difficulties mounting immune responses against new pathogens. Consequently, many diseases, including cancer, tend to occur amongst the elderly. Apoptosis (depicted in the illustration at the right) fails to work properly and cancerous cells grow in number and strength. 

Changes in the Body

Senescence is a normal physiological process in which organ function slowly changes with age. When it concerns the immune system, it is termed immunosenescence. The organs of the lympatic system change. The thymus gradually recedes and degenerates, resulting in a decrease in T cell output. Production of cytotoxic molecules decreases, reducing the body's ability to fight infection. Metabolism slows, energy reserves decline, telomeres shorten and B cells (sole producers of antibodies) fail to activate fully. The underlying mechanism of tumorigenesis (creation of cancerous tumors) is closely associated with immunosenescence. 

Zombie Cells

Senescent cells or "zombie" cells were first observed in 1961 by researchers studying human fibroblast cells. Fibroblast cells support and connect tissues and organs in the body. Researchers found that these cells could only replicate a limited number of times in a lab dish. Eventually, they became inactive and could no longer divide. 

Many cells in an adult become specialized for a particular function, such as forming the brain, and do not frequently reproduce. However, some cells, such as skin and blood cells, divide constantly, leading to the continuous renewal of these parts of the body.
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A zombie cell is in its twilight: not quite dead, but not functioning as it did at its peak. For example, a zombie sweat gland cell decreases sebum production by as much as 60 percent, resulting in visibly less smooth skin. While zombie cell functions have diminished, they continue to resist death and release harmful biological signals that can impair cognition, increase frailty, and weaken the immune system. To make matters worse, their numbers grow as we age.

Zombie cells can release a combination of harmful molecules and secrete inflammatory signals, such as cytokines and proteins, that affect the function of nearby cells and induce local inflammation. 

Immune cells can also age, and the outcome can be even more disastrous. Immune zombie cells, attracted by the inflammatory signals from other zombie cells, secrete their own inflammatory molecules. Not only do they fail to clean up the mess, but they also add to the inflammation.

This phenomenon, known as “inflammaging,” is a long-lasting vicious cycle of destruction and the cause of many chronic diseases. This is why an accumulation of zombie cells and age-related inflammation is associated with many diseases, including cancer, diabetes, heart disease, kidney disease, and Alzheimer’s disease.

What to Do About It?

While the aging process results in a normal decline of function, a variety of factors govern the speed and severity of the decline. Reduction in exposure to environmental toxins, increased attention to correct nutrition, and regular exercise can be utilized to strengthen and restore immune system competency. It is possible to decline gracefully with age, while limiting the risk of debilitating sickness and disease. 

​Caloric restriction via intermittent fasting is extremely effective in improving longevity. It sometimes feels like starvation, but the body thrives in an environment where calories are seriously restricted. Also, studies show that the combination of two compounds (Dasatinib and Quercetin) holds promise. Dasatinib is a kinase (enzyme) inhibitor that targets a specific cell protein to treat leukemia and slows the growth of cancer cells in the body. Quercetin is a potent flavonoid (antioxidant) known for its anti-inflammatory, anti-hypertensive, and anti-obesity activities. It belongs to a class of flavonols that cannot be synthesized in the body, but are widely available in fruits, leafy greens, and various seeds, barks, and nuts. 

Eliminating highly-processed food and eating real, whole food while supplementing with plant-based nutrition are critical for vibrant health. For more information, see my book.