By Dr. Frank Sabatino

In recent years, an erroneous narrative and  pandemic of fear has been promoted in response to extensive viral infection. The profound capability for healing that resides within each of us has been overlooked, minimized and disrespected. We have all been distanced from the incredible ability of the body to protect itself, and the true biology of hope inherent in the wisdom of the body, that maintains stability and health in the face of environmental challenges.

There is no better example of body wisdom than our immune system and immune response. This response is a well orchestrated symphony of action and protection that recognizes everything that is or is not you. So that if you encounter a bacterial or viral infection, the immune system has to make a spot decision to protect you against what’s not you. As much as we have all been medically influenced to see acute symptoms as negative things to be treated and eliminated, the immune system manifests the remedial actions of fever and inflammation to protect you against infection and promote healing of injured and damaged body parts. But if these essential actions are not regulated and controlled, they may promote more damage than their worth. Lifestyle choices that promote chronic inflammation and damage to the cells and organs of the body can tax and compromise the immune system, and increase morbidity and mortality from infection.

Every day you and I interact with a plethora of bacteria and viruses, as well as the trillions of organisms that live within us. Yet we do not walk around in a constant state of  disease. It is so important to realize that this exposure and contact with organisms is unavoidable and essential for challenging and strengthening the immune system. And as much as social distancing has protective value in the face of overwhelming infection, some degree of social contact and exposure ultimately enhances immune protection for the individual as well as the herd of humanity. Our immune response is a synergy of both innate (inborn) and adaptive (acquired) immunity. When we first encounter an infection or injury to the body, the immediate innate response relies on natural barriers of skin, mucous linings of the mouth, nose, lungs, gastrointestinal and genitourinary systems as well as stomach acid for initial protection. 

This barrier protection is supported by the next line of innate protection as the immune system (made up of bone marrow, spleen, thymus gland and lymph nodes) produces a population of white blood cells ( mast cells, neutrophils, macrophages, and natural killer cells ) that promote inflammation, and the clean up of infected cells. If the threat is severe and ongoing, the innate and acquired immune responses are linked  to elicit white blood cells called T cells and B lymphocytes that promote long term acquired immunity. 

Helper and cytotoxic T-cells play a major role in eliminating damaged, infected cells, while B cells produce antibodies that block viruses and bacteria from infecting cells and also prevent future infection. The immune system engenders a remarkable synergy of present and long term protection that not only acts in the moment but promotes a chemical memory of cells and antibodies that store information about viruses and bacteria for specific protection in the future. However, the function, and even aging of the immune system, is a fluid, changing process that is modified by a variety of outside environmental/lifestyle factors. The choices you make in nutrition, activity and stress response provide influences that can remarkably enhance or suppress the resilience and function of your immune system.

Deviation from a whole plant-exclusive diet, and the dietary excesses of meat, dairy, and ultra-processed foods in a typical American diet loaded with refined  oils, sugar, and salt,  produce  increases of saturated/ trans/oxidized fat, oxidized cholesterol, methionine, arachidonic acid, neuraminic acid, heme iron from meat, and TMAO produced by the gut microbiota (1). These excesses can increase free radical damage and inflammation which may chronically stimulate and compromise the immune system over time, and  maintain a cellular environment that can increase the susceptibility and morbid consequences of infection. (2) 

Keep in mind, that the structure of all chemicals in the body determines their function. The increased consumption of trans and oxidized fats can alter the structure/function of cell membranes, allowing things to enter cells that would normally be blocked. As a result, cells can be more prone to the entry of bacteria and viruses increasing the risk of infection. Also, The omega-3 pathway in the body,  starting with the essential fatty acid alpha-linolenic acid, contained in greens, walnuts, soy proteins, legumes, flax, chia and hemp seeds that are typically deficient in the standard American diet, reduces inflammation. So as the diet becomes less plant focused, a baseline of inflammation can be enhanced, that can magnify cell damage, morbidity and even mortality in the face of infection. 

As you consider the power and benefits of plant nutrition, please recognize that the dependence of our population on animal food production is arguably  a significant and devastating cause of recent, current and future viral pandemics. These viruses are found in a variety of other animals and subsequently transmitted to human hosts as a form of zoonotic infection. The deplorable crowded conditions of animal factory farms, and foreign markets wet with the blood, urine, and feces of stacked, caged and eventually slaughtered animals, play a significant role in the spread of these infections. 

The Gut Microbiota (GM) is the diversity of trillions of organisms that reside in our intestine and support the production of the protective mucous lining of the large intestine which is part of the innate immune system. The GM requires the fiber in plant food to thrive and function at its best. When you eat a variety of plant foods, you support the healthiest diversity of the GM and the production of short chain fatty acids (SCFA), that maintain the integrity of the mucous lining of the large intestine and decrease inflammation. (3) 

An increased consumption of animal protein, saturated fat, low fiber junk food and alcohol  increase pathogenic organisms in the gut (dysbiosis), and promote an unhealthy decrease of GM diversity. This can decrease the production of SCFA, damage and break down the mucous lining, increase inflammation/exaggerated immune and autoimmune activity, and decrease your innate protection against bacterial and viral infection. The GM also transforms phytonutrients in plants, polyphenols (isoflavones in soy, curcuminoids in tumeric, tannins in berries, pomegranates, walnuts and almonds) to activate cells of the immune system, including T/B cell lymphocytes, neutrophils and macrophages, to decrease inflammation and viral infection. (4)(5)

Sunshine is one of the important biological requirements of life, and a profound and key factor for healthy immune resilience. When sunlight hits the cholesterol in your skin, it produces Vitamin D3 that is transported and ultimately converted in the kidney to its final form, calcitriol,  and sent to bone, kidney and the intestine. Vitamin D plays an important role in balancing the innate and adaptive immune response. There are Vitamin D receptors on T, B and antigen presenting cells of the immune system suggesting a direct activation of the immune response by Vitamin D. In fact, cells in the immune system can produce the active form of Vitamin D just like the kidney which suggests how important some routine sun exposure and/or Vitamin D supplementation is for a healthy immune system. (6) 

Vitamin D can also support a reduction of  dysbiosis and the inflammatory environment of the gut. Importantly, Vitamin D can also decrease acute viral respiratory infection. (7) That was so important in the recent Sars-Cov 2 (coronavirus associated with COVID-19) infection . Especially since one of the most devastating outcomes of these respiratory viruses is lung infection/damage that leads to pneumonia and the inability to breathe; increasing the need for ventilators, emergency hospitalization and potentially increased mortality.

There are also important proteins that help the immune system resist and defend viral infection. These Host Defense Proteins (HDP) are part of the innate immune response and are produced at barrier sites that have contact with the outside environment (mouth, nose, respiratory system). Vitamin D significantly increases HDP to reduce infection.

Cathelicidin is a prominent HDP that has significant anti-viral activity. (8) Keep in mind that viruses can not replicate and reproduce on their own. They must penetrate your cells, release their genetic instructions, and hijack your own genetic machinery to reproduce and damage your body. Cathelicidin blocks viruses from attaching to  cells, increases cell stiffness and decreases the ability of viruses to pass into cells (permeability) in the lungs to dramatically decrease the possibility of viral lung infections. This HDP can also attach directly to the virus and breakdown the viral membrane/envelope to destroy the virus before it even affects the cells of the body. (9) 

Interestingly, Vitamin D, and the SCFA produced by the GM  fiber in whole plant foods, will synergize and enhance the anti-viral effects of Cathelicidin. And Vitamin D also promotes genes that produce both HDP,  and the proteins that tighten cells of the large intestine to prevent toxins and pathogens from entering the bloodstream, to support an anti-viral and anti-bacterial immune response. As a result, I can not overstate how important routine sun exposure is for protection against infection. 10 -15 minutes of sun exposure, early morning or later afternoon, 4-5 times a week should be sufficient. But if you are unable to get out for routine sun exposure during long stretches of the year, and your blood test for Vitamin D is low, supplementation of Vitamin D3 is recommended.

Moderate consistent exercise/walking (30-minutes a day), enhances both  the innate and adaptive immune response. This level of exercise increases the activity of natural killer cells, cytotoxic T cells/ B cells, neutrophils and macrophages and reduces cytokines associated with increased inflammation thereby reducing the risk of cell damage and morbidity. (10) Routine walking also reduced the incidence and duration of upper respiratory tract infections, increased the production of anti-oxidant enzymes, decreased inflammation, oxidative stress and cell damage and increased the clearance and removal of bacteria and viruses by the immune system. (11)(12) Since fat cells produce their own inflammatory factors (adipokines), it is important to note that plant-exclusive nutrition and exercise can also significantly reduce the risk of obesity can increase the resilience of the immune system and decrease the morbidity and mortality of dangerous viral infections. 

The immune system does get more dysfunctional with age so that elderly people are more susceptible to infection, cancer and metabolic diseases. (18) However, it is so important to understand that the immune response  can be remodeled and improved at any age by constructive lifestyle choices. Studies comparing sedentary, elderly men and women to active and conditioned peers show a decrease in illness and an increase in the immune response by significant increases of natural killer and T cells. (13)(14) Since habitual exercise increases the activity and proliferation of T and natural killer cells, decreases aged, exhausted T cells, decreases inflammation and cell damage by naturally lowering the body’s inflammatory response to bacterial and viral infection, exercise is an invaluable, necessary tool to improve and support the resilience of the immune system as you get older.

Water-only fasting promotes unique benefits and resilience of the immune system. Just 3-5 days of fasting can produce significant anti-inflammatory effects. People dealing with inflammatory and autoimmune disease show dramatic reductions in inflammation, and the inflammatory bio marker C-reactive protein suggesting a beneficial down regulation of the entire immune response. In addition, water-only fasting for just 3 days prompts stem cells to create and activate new white blood cells effectively regenerating the immune system. So that water-only fasting may be a very valuable tool for resisting and/or reducing viral or bacterial infection.

Chronic stress has a major impact on the resilience of the immune system and your vulnerability to viral infection. The fight or flight stress response evolved to help you resolve acute emergencies and threatening situations via the release of the hormone cortisol, and certain neurotransmitters, from your adrenal glands. Unfortunately, for all of us, at times the stress of our lives can become more chronic and ongoing driving a sustained release of stress hormones that eventually exhaust the body and adrenal glands. Excessive cortisol release during relentless, chronic stress can decrease the body’s protective immune response, and decrease the proliferation and activity of cells essential to innate and adaptive immunity. This is consistent with the observation in chronic caregivers and other people dealing with chronic stress, of slower wound healing and increased susceptibility to bacterial and viral infection. In addition, chronic, excessive cortisol release in chronic stress also promotes increase body fat , weight gain,  dysbiosis of the GM , damage to the mucous lining of the bowel, exaggerated inflammation and aberrant regulation of the immune response. This clearly highlights the importance of managing your stress response with physical activity, restorative sleep, breath work, mindful meditation etc. for enhancing the function and resilience of the immune system.

We are all endowed with a remarkable ability to protect and heal ourselves from injury and pathogenic invaders in the environment. As sophisticated, intricate and magnificent the immune system is,  simple, constructive lifestyle choices absolutely enhance its resilience and function. There is no reason to live in fear. It is important to embrace the hope that is grounded in the wisdom of the body. Always keeping in mind that the choices that promote healthy living also have the greatest impact on eliminating the conditions that magnify the risk and damage of infection. These choices are always yours to make and always within your reach.

REFERENCES

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(5) Amin, HP et al. Anthocyanins and their physiologically relevant metabolites alter the expression of IL-6 and VCAM-1 in CD40L and oxidized LDL challenged endothelial cells. Mol Nutr Food Res (2015) Jun;59(6):1095-1106.

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(7) Sabetta, JR et al. Serum 25-hydroxyvitamin D and the incidence of acute viral respiratory tract infections in healthy adults. PLOS ONE (2016) 5(6):e11088.

(8) Tripath, S et al. The human cathelicidin LL-57 inhibits influenza A viruses through a mechanism distinct from that of surfactant protein D or defensins. J Gen Virol (2013);94 (Pt 1):40-49.

(9) Barlow PG et al. Antiviral potential of cathelicidins. Future Microbiology, 2014;9(1):56-73.

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(11) Nieman, DC. Moderate exercise improves immunity and decreases illness rates. Am J Sports Med (2011);5(4):987-992.

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(13) Turner, JE et al. Oxid Med Cell Longev (2017) Article: 4234765

(14) Simpson, RJ et al. Exercise and the ageing immune system. Ageing Res Rev (2012) July;11(3): 404-420.