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  • Omie Mills, M.D.

Covid 19 (Part 2): Optimize your immune system to prevent or minimize infection


Hopefully, COVID-19 is winding down for good. At the time of this writing, over 32 million people in the United States have had confirmed SARS-CoV-2 infections with over 580,000 deaths from COVID-19. (See the attached link for up-to-date statistics: Coronavirus Update: Maps And Charts For U.S. Cases And Deaths : Shots – Health News : NPR) Among the infected persons, some had no symptoms. Why are some people asymptomatic while infected, while others get severely ill, and still others die? If we can answer this question for COVID-19, we can theoretically learn some principles for avoiding similar infections in the future.

Asymptomatic Infections

Why are some people asymptomatic while infected with the coronavirus that causes COVID-19?

The World Health Organization (WHO) defines an asymptomatic person as a laboratory-confirmed infected person without overt symptoms (1).

Research early in the pandemic suggested the rate of asymptomatic infected individuals to be up to 81% (2). But a recent meta-analysis including 13 studies with 21,708 people followed for a minimum of 7 days after exposure (to help differentiate between pre-symptomatic and asymptomatic patients) suggests that the rate of asymptomatic presentation is 17% (3). This is an updated statistic from that presented in part 1 of this blog.

Recent studies (4, 5, 6, 7, 8, 9, 10) have shown asymptomatic individuals have the following characteristics:

  1. Younger age

  2. Female > male

  3. Exhibit normal laboratory values for liver function and proteins

  4. Inflammatory markers and indictors of tissue damage are within the normal range (ie. erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), and lactate dehydrogenase (LDH))

  5. Possess adequate numbers of T and B cells and natural killer (NK) cells

  6. Fewer coexisting diseases.

While some of these risk factors cannot inherently be changed, many can be improved with simple lifestyle changes, discussed below.

Can I decrease the risk of severe COVID-19 infection associated with advanced age?

While chronological age (how old you are in years) increases at the same rate for everyone and is non-modifiable, the aging process of the cells of your body (biological age) can be modified.

How fast our cells age depends on many factors (11, 12). While genetics play a significant role, other factors include the following:

  • Diet and nutrition

  • Exercise

  • Stress

  • Sleep

  • Exposure to environmental and other toxins

  • Chronic conditions

Your body’s biological age can be measured. Researchers have found correlations between the aging of body tissues and a measurable process called DNA methylation, also known as “epigenetic clocks.” The extent to which your DNA contains methyl groups can be influenced by “not only age, but by a wide range of environmental and biological factors, including your diet, your physical health, your microbiome, your mental/emotional health, and environmental factors like exposure to tobacco smoke and other pollutants” (13).

Telomere length is another age- and health-associated biomarker. Telomeres are structures found on the end of chromosomes that are responsible for protecting DNA’s structure and function. Shorter telomeres are associated with increased biological age and poorer health. While telomeres will shorten with chronological age, some factors may speed up the process including:

  • Poor diet (14)

  • Obesity (15)

  • Smoking (16)

  • Less than adequate amounts of sleep (17)

  • Lack of exercise (18)

So, while an older chronological age may suggest a risk of more severe disease if infected with the coronavirus that causes COVID-19 or something similar, the good news is that biological age is modifiable which may allow for an asymptomatic or mild infection.

Does smoking increase my risk of severe COVID-19 infection and death?

In a scientific brief from the World Health Organization (19), the following statements are made:

“The harms of tobacco use are well-established. Tobacco causes 8 million deaths every year from cardiovascular diseases, lung disorders, cancers, diabetes, and hypertension. Smoking tobacco is also a known risk factor for severe disease and death from many respiratory infections.”

“…the available evidence suggests that smoking is associated with increased severity of disease and death in hospitalized COVID-19 patients.”

“Given the well-established harms associated with tobacco use and second-hand smoke exposure; WHO recommends that tobacco users stop using tobacco.”

Can drinking alcoholic beverages increase my risk of severe COVID-19 infection and death?

The World Health Organization makes the following recommendations regarding alcohol, and dispels myths regarding the use of alcoholic beverages and COVID-19 (20):

Avoid alcohol altogether so that you do not undermine your own immune system and health and do not risk the health of others. Stay sober so that you can remain vigilant, act quickly and make decisions with a clear head, for yourself and others in your family and community.”

General myths about alcohol and COVID-19:

Myth: Consuming alcohol destroys the virus that causes COVID-19.

Fact: Consuming alcohol will not destroy the virus, and its consumption is likely to increase the health risks if a person becomes infected with the virus. Alcohol (at a concentration of at least 60% by volume) works as a disinfectant on your skin, but it has no such effect within your system when ingested.

Myth: Drinking strong alcohol kills the virus in the inhaled air.

Fact: Consumption of alcohol will not kill the virus in the inhaled air; it will not disinfect your mouth and throat; and it will not give you any kind of protection against COVID-19.

Myth: Alcohol (beer, wine, distilled spirits or herbal alcohol) stimulates immunity and resistance to the virus.

Fact: Alcohol has a deleterious effect on your immune system and will not stimulate immunity and virus resistance.

What type of diet should I be eating to optimize my immune system to fight infection?

Eat a plant-based diet

According to The Permanente Journal, in a nutritional update for physicians to help their patients adopt healthier lifestyles, the following statement is made: “Healthy eating may be best achieved with a plant-based diet, which we define as a regimen that encourages whole, plant-based foods and discourages meats, dairy products, and eggs as well as all refined and processed foods.” “Research shows that plant-based diets are cost-effective, low-risk interventions that may lower body mass index, blood pressure, HbA1C, and cholesterol levels. They may also reduce the number of medications needed to treat chronic diseases and lower ischemic heart disease mortality rates. Physicians should consider recommending a plant-based diet to all their patients, especially those with high blood pressure, diabetes, cardiovascular disease, or obesity” (21).

Whole, plant-based foods include fruits and vegetables, whole grains, beans, nuts, and seeds. These foods contain many vitamins, minerals, fiber, and antioxidants that are needed for ultimate health, and their consumption can boost the immune system.

According to UK doctors, “Going vegan is one of the simplest, cheapest things Britons [or anyone] can do to slash the risk of becoming seriously ill with COVID-19. Now more than ever before it’s time to embrace the benefits of a plant-based diet before it’s too late.” “A healthy vegan diet can help you lose weight, reverse Type 2 diabetes and protect heart health, reducing your risk of severe COVID-19” (22).

Dr. Michael Gregor, M.D. FACLM, says “What we eat—or don’t eat—can affect our immune system” (23) and recommends using the produce isle to boost our immune system (24).

And, did you know 70 to 80% of your immune system resides in your gut (25)? A plant-based diet sustains a healthy gut microbiome (the microorganisms living in the gut that help to break down food, protect against pathogens, and effect mood and psychological processes) (26). “A strong microbiome empowers the neighboring immune cells for optimal function” (27).

In a recent article by T. Colin Campbell, PhD, who studied diet, lifestyle, and disease mortality in China and Taiwan as well as the hepatitis B virus (HBV) which causes primary liver cancer, Dr. Campbell relates finding that “HBV antibody prevalence was highly correlated with vegetable consumption, dietary fiber, and plant protein. In short, more plant food consumption was associated with more antibodies” (28). Given that the microorganism that causes COVID-19 is also a virus, he states, “I believe that this consistent interplay of nutrition, virus activity, and disease should apply to coronavirus (COVID-19) as well, especially for older individuals compromised by diseases arising from the same nutrition that decreases antibody formation. Switching to a whole-food, plant-based diet should lessen the severity of disease symptoms while simultaneously increasing COVID-19 antibodies, a win-win effect. Based on other studies, this effect may begin within days, possibly providing enough time for people not yet infected by COVID-19 to strengthen their immunity” (28).

In a randomized controlled trial of elderly patients (those generally at greatest risk of respiratory infections, patients increased their daily intake of fruits and vegetables to five portions per day (29). The control group continued with approximately 2 portions per day. Those who ate more fruits and vegetables showed an enhanced antibody response following vaccination. Researchers concluded that eating five fruits or vegetables per day improved immune function.

Eat less fat

In the American Society for Microbiology, increased dietary fats are postulated to affect the gut microbiome and intestinal permeability allowing for an increase in Gram-negative bacteria in the gut, and their product, endotoxin, into the circulation, thus contributing to and exacerbating the inflammatory response that contributes to the high mortality in coronavirus disease (COVID-19). “Shifting from a diet high in saturated fats to one with monosaturated fats will reduce the numbers of those bacteria that produce the most inflammatory endotoxin molecules and thereby reduce the severity of the inflammatory response to a COVID-19 infection in vulnerable individuals…” (30).

A recent study found that the virus that causes COVID-19 needs cholesterol in order to enter and infect cells (31). When cholesterol levels are low, there are very few entry points into cells (as in the case of most children). The higher a person’s cholesterol level, the more entry points are available for the virus to enter and infect cells. Dr. Kim Williams, former president of the American College of Cardiology, says, “Anything that you can do to lower your … cholesterol, even during an infection, seemed to be helpful” (32).

“People can reduce their cholesterol levels dramatically by changing the foods they eat. Diets high in saturated fats, trans fats, and cholesterol—found in meat, dairy products, and eggs—raise cholesterol levels, which increases heart attack risk [and increase the ability of the COVID-19 virus to infect cells]. Foods high in saturated fat are especially dangerous because they can trigger the body to produce extra cholesterol.

Plants do the opposite. They are very low in saturated fat and free of cholesterol. Plants are also rich in soluble fiber, which helps lower cholesterol. Soluble fiber slows the absorption of cholesterol and reduces the amount of cholesterol the liver produces. Oatmeal, barley, beans, and some fruits and vegetables are all good sources of soluble fiber” (33).

The ideal blood cholesterol level is below 150 milligrams per deciliter (mg/dL), based on the results of the Framingham Heart Study and other research (34). At that level, heart disease is very unlikely.

And, based on recent study findings noted above, this low cholesterol level has the potential to protect you from severe COVID-19 as well.

Eat less free sugar

Laura Schmidt, PhD, a sugar scientist and professor of health policy at the University of California at San Francisco, in an interview with Healthline stated, ““Many people will say there isn’t much that can be done about obesity rates within the context of an infectious disease pandemic, but just taking the sugar out of your diet can potentially lower your risk for severe outcomes if you do get the virus,” Schmidt said. “We know from controlled feeding trials, where we feed people a particular diet and look at their metabolic biomarkers, that within a couple of weeks of going on a no-sugar diet their insulin sensitivity and biomarkers for chronic metabolic disease actually get better” (35).

Sugar can also trigger inflammation in the body and contribute to obesity, diabetes, metabolic disease, and subsequently cardiovascular disease… all known risk factors for a more severe course of COVID-19 (36).

“Consuming too much sugar can affect the cells in your immune system that target bacteria. … Sugar affects the way your white blood cells attack bacteria.” explained board-certified internist and gastroenterologist Niket Sonpal (36).

Current American Heart Association recommends men should consume no more than 9 teaspoons (36 grams) of added sugar per day, while women should consume no more than 6 teaspoons (25 grams) per day (37).

The World Health Organization (WHO) recommends adults and children reduce their daily intake of free sugars to less than 10% of their total energy intake, noting that a reduction to below 5% or 25 grams (6 teaspoons) per day would give additional health benefits (38).

Are there any foods and/or supplements that I can take to boost my immune system to fight off an infection like COVID-19?


Garlic contains an organosulfur compound (allicin) that is antiviral. Some mechanisms of action include hindering viral attachment to host cells, altered transcription and translation of viral genomes in host cells, it affects viral assembly, and can pass through phospholipid membranes of cells and inhibit viral multiplication (39, 40).

Garlic activates genes related to immunity (41), suppresses proinflammatory cytokines, and increases immune system function by stimulating macrophages, lymphocytes, natural killer cells, eosinophils, by modulating cytokine secretion, and immunoglobulin synthesis (42).

In a double-blind, placebo-controlled study (43), 146 subjects were randomized to a placebo or allicin-containing garlic supplement, one capsule daily, over a 12-week period (between November and February). The treatment group that took the daily garlic capsule had significantly fewer colds and were faster to recover if infected. The control group taking the placebo got sick more often and for longer periods of time.

Garlique (a garlic supplement that can be purchased at Walmart, or off of, for example) contains 5,000 micrograms of allicin per tablet. A fresh garlic clove contains approximately 5, 000 to 14,000 micrograms/gram of allicin (44). Cooking garlic destroys some of the helpful effects of garlic (45).

Safety precaution: Garlic (both supplemental and garlic cloves) can increase your risk of bleeding, and may interact with anticoagulants such as coumadin, so if you are on a blood thinner, contact your doctor before starting garlic supplementation (46, 47).


Quercetin (found in onions, citrus fruits, apples, parsley, sage, grapes, dark cherries, and dark berries such as blueberries, elderberries, blackberries, and bilberries) (48) is a plant pigment (flavonoid), an organosulfur compound which may decrease respiratory symptoms and/or the duration of respiratory illnesses significantly (49). It inhibits RNA polymerase which is necessary for viral replication (50).

It can affect entry and attachment of Enterovirus and Influenza virus on host cells (51, 52). It also possesses antioxidant and anti-inflammatory effects which might reduce inflammation (53).

Quercetin functions as a zinc ionophore and has been shown to facilitate the transport of zinc across lipid membranes (54). Coronavirus appears to be susceptible to the inhibitory actions of zinc, which may prevent viral entry into cells (55) and appears to reduce coronavirus virulence (56). Quercetin could, theoretically, enhance the antiviral actions of zinc (57). Human studies are currently underway to evaluate the effects of quercetin in preventing and treating COVID-19 infections (58).

Quercetin supplements – “Common oral dosages are 500 milligrams twice a day. People have also used lower dosages as well. However, optimal doses of quercetin have not been established for any condition” (59).

Quercetin may affect medications (i.e those metabolized by CYP2C8, CYP2D6, CYP3A4, and P-glycoprotein substrates) (60). If you are on medications, talk with your doctor before starting this as a supplement. In the meantime, eating foods that contain quercetin in regular amounts may be a safer alternative to supplementation.


Zinc is a common trace mineral found in the body. As a micronutrient, it affects all organs and cells, and is needed to properly smell and taste. Over the years, studies have found that if people have low levels of zinc, they are more likely to develop infections and other chronic health conditions including diabetes, pneumonia, and sepsis.

Zinc has been shown to impair the replication of a number of RNA viruses (like coronavirus). Zinc coupled with an ionophore (a substance that helps zinc get into the cell like quercetin discussed above) inhibits SARS-CoV replication. Zinc directly inhibits the coronaviral RNA-dependent RNA polymerase, thus repressing viral replication in cells (61). It has also been shown in vitro to increase cytotoxicity and induce apoptosis (cell death) when used with an ionophore, like hydroxychloroquine (and quercetin) (62, 63).

Some have also suggested that using a lozenge which contains zinc can help prevent infection from coronavirus introduced through the mouth as it kills it on contact (64).

In a study from Spain (65), researchers studied 611 patients with COVID-19 and found that patients who died had an average zinc blood level of 43 micrograms per deciliter, compared with survivors whos’ average zinc-blood level was 63 micrograms per deciliter, a level considered to be close to normal. For each unit increase in zinc-blood level, there was a 7% lower risk of in-hospital death. On admission to the hospital, having a plasma zinc level lower than 50 micrograms per deciliter was associated with a 2.3 times increased risk of dying in the hospital compared with patients whose levels were equal to or greater than 50 micrograms per deciliter.

Trials are underway to continue to evaluate the effectiveness of this element (66).

To learn what foods contain zinc, visit the following website (67):

Zinc supplements can be purchase in a variety of doses. The reported maximum doses of zinc being used in trials is equivalent to 50 mg of elemental zinc, twice per day. However, the recommended dietary allowance for elemental zinc is 11 mg per day for men, and 8 mg per day for non-pregnant women.

It is important to note that prolonged zinc supplementation (i.e. after 10 months) has been associated with copper deficiency. Zinc supplementation has also been associated with an increased incidence of prostate cancer. “…a recent study involving 46,000 health professionals (the Health Professionals Follow-up Study) found that men who consumed more than 100 mg/d of supplemental zinc had a higher relative risk (2.9-fold) of advanced prostate cancer. This increase in risk was amplified with the long-term intake of zinc supplements for more than 10 years” (68).

N-acetyl L cysteine

N-acetyl L cysteine (also referred to as NAC) is a precursor of the antioxidant glutathione, and can be purchased as an over-the-counter supplement. It has been used for decades to treat acetaminophen overdoses and to loosen mucus in the lungs. NAC can also reduce inflammation, boost the immune system, and repress viral replication (69).

In 1997, a study demonstrated that taking one tablet (600 mg) of NAC by mouth twice per day significantly decreased the frequency of influenza, the severity of the disease, and the duration of symptoms (70). Interestingly, only 25% of subjects taking the NAC treatment who were infected with influenza developed flu symptoms, compared with 79% of those who were given a placebo. That means that 75% of those on the NAC treatment in this study were asymptomatic when later infected with influenza.

In “N-Acetylcysteine to combat COVID-19: An Evidence Review” (71), the use of NAC to treat COVID-19 patients at different stages of the disease are reviewed and the following conclusions are drawn: “N-acetylcysteine (NAC) is inexpensive, has very low toxicity, has been FDA approved for many years, and has the potential to improve therapeutic strategies for COVID-19” (71). It “…may suppress SARS-CoV-2 replication and may improve outcomes if used timely” (71). It may mitigate inflammation and tissue injury, and in combination with other antiviral agents, “may dramatically reduce hospital admission rate, mechanical ventilation and mortality” (71).

Can exercise boost my immune system?

Regular exercise may reduce the risk of acute respiratory distress syndrome, a major cause of death in patients with the COVID-19 virus, a top exercise researcher reports.” Zhen Yan, PhD, the director of the Center for Skeletal Muscle Research at the Robert M. Berne Cardiovascular Research Center compiled an in-depth review, including his own research, of an antioxidant, extracellular superoxide dismutase (EcSOD) (72). This potent antioxidant destroys harmful free radicals, protecting our tissues, and preventing disease. “ Research indicates that the antioxidant is decreased in several diseases, including acute lung disease, like COVID-19. Our muscles naturally make EcSOD, secreting it into the circulation to allow binding to other vital organs, but its production is enhanced by cardiovascular exercise” (72). Research suggests that even a single episode of exercise increases the production of EcSOD. “Regular exercise has far more health benefits than we know” (72). Boosting immune function via exercise could reduce the chance of infection or severity of disease (73).

The World Health Organization (WHO) has stated that regular physical activity can reduce and/or help manage the high blood pressure, type 2 diabetes, heart disease risks, obesity, stroke, and various cancers, all of which can increase susceptibility to and the severity of COVID-19 (74).

The WHO and the CDC recommend 150 minutes a week of moderate intensity exercise such as brisk walking or 75 minutes a week of vigorous aerobic exercise such as jogging or running, plus muscle strengthening exercises that work all muscle groups two or more days per week (75). If you have an injury or illness, check with your doctor or medical provider to develop an appropriate workout plan for your level of health and fitness.

Does vitamin D protect against COVID-19?

“There is some evidence to suggest that vitamin D might help protect against becoming infected with, and developing serious symptoms of, COVID-19. We know, for example, that people with low vitamin D levels may be more susceptible to upper respiratory tract infections. One meta-analysis found that people who took vitamin D supplements, particularly those who had low vitamin D levels, were less likely to develop acute respiratory tract infections than those who didn’t. Vitamin D may protect against COVID-19 in two ways. First, it may help boost our bodies’ natural defense against viruses and bacteria. Second, it may help prevent an exaggerated inflammatory response, which has been shown to contribute to severe illness in some people with COVID-19” (76).

Vitamin D can be manufactured by our bodies when our skin is exposed to sunshine. How much vitamin D is produced depends on the skin type of the person (lighter skinned individuals create more Vitamin D in a shorter amount of time than dark skinned individuals), where you live in the world, and the season (winter versus summer) (77). In many cases, Vitamin D supplementation is needed to maintain adequate levels. “A daily supplement containing 1,000 to 2,000 IU of vitamin D is likely safe for most people. For adults, the risk of harmful effects increases above 4,000 IU per day” (78).

Have you heard of steam inhalation to treat COVID-19?

Of note, a study of a small group of SARS-CoV-2-positive people found that steam inhalation for 20 minutes for 4 consecutive days decreased viral shedding and improved symptoms. “This study, although a small one, shows the beneficial effects of steam inhalation in reducing viral shedding from infected patients. The team writes that this could be an “easily accessible, non-invasive and inexpensive procedure” which has been proven to be effective” (79).

For directions on how to perform steam inhalation visit the following link:

Remember, steam is hot so follow the directions carefully to prevent burn.

Are there essential oils that may be beneficial to prevent or treat COVID-19?

Essential oils obtained from eucalyptus (Eucalyptus globulus) have been used in the past to treat respiratory conditions such as sore throat, sinusitis, and bronchitis. One of the active constituents of eucalyptus, 1,8-cineole acts as a muscle relaxant by decreasing smooth muscle contractions in airways (80). Eucalyptus essential oil also has anti-inflammatory, immunomodulatory, bronchodilatory, and antiviral properties (81).

Additionally, it has been shown to stimulate the innate cell-mediated immune response (82). A review-based hypothesis sought to demonstrate the beneficial role of eucalyptus in COVID-19, suggesting that inhaling eucalyptus essential oil may relieve COVID-19 mild to moderate symptoms including pain, cough, respiratory inflammation, cytokine storm, and dyspnea (83).

Do not take eucalyptus by mouth unless under a physician’s direction, as Eucalyptus can be toxic in this form, and in high doses! Eucalyptus oil may be used as a chest rub or inhaled in steam. Eucalyptus essential oil may be inhaled by using an essential oil diffuser, or [see pics below] by adding 3-4 drops of the essential oil to a medium-to-large pot of boiling water and following the steam inhalation instructions in the attached link: Steam Inhalation (

Is sleep protective against COVID-19?

In the study, “Sleep habits and susceptibility to the common cold” (84), 153 healthy men and women with an age range of 21-55 years reported their sleep duration and sleep efficiency (percentage of time in bed actually asleep) over a 14 day period. The study participants were then quarantined, and then, drops containing a common cold virus (rhinovirus) were administered nasally. The study participants were monitored for the day prior to and for the subsequent five days after the nasally administered virus for the development of cold symptoms. This study found that subjects who slept less than 7 hours per night were almost 3 times more likely to develop a cold than those who slept 7 or more hours per night. Additionally, participants who had less than 92% sleep efficiency were 5.5 times more likely to develop cold symptoms than those whose sleep efficiency was 98% or better. Thus, sleep was determined to play a causal role in cold susceptibility. The coronavirus that causes COVID-19 is also a cold virus, and theoretically, should respond to sleep similarly to Rhinovirus.

As a quick tip, should you catch COVID-19 and develop respiratory symptoms, note that sleeping on your stomach (preferred) or side, rather than on your back can improve your oxygen saturation levels. Many hospitals implement this positioning of patients to help them avoid progression to a ventilator. “After just 5 minutes of proning, sat levels rose to a near-normal mean of 94%. And in the end, about three-quarters of the patients never had to be put on a ventilator” (85, 86, 87).

Are there any benefits to getting “fresh air” in the prevention and/or treatment of COVID-19?

Is fresh air the “forgotten weapon” in the fight against COVID-19 (88)?

Concerning indoor air, the CDC recommends bringing in as much fresh air into your home as possible, and states “Bringing fresh, outdoor air into your home helps keep virus particles from accumulating inside” (89). This advice holds true for any enclosed space.

“Changing the room air is a widely used measure for infection prevention and control,” says Stephen Morse, an infectious disease researcher and professor of epidemiology at Columbia University’s Mailman School of Public Health (90). “It replaces any virus-contaminated air with clean air” (90). Opening windows is one of the easiest and cheapest ways to encourage this type of air turnover, he says.

What about getting fresh air by spending time outside in “green spaces.” In ScienceDaily, a study from the University of East Anglia states, “It’s official – spending time outside is good for you” (91).

“We gathered evidence from over 140 studies involving more than 290 million people to see whether nature really does provide a health boost.”

“We found that spending time in, or living close to, natural green spaces is associated with diverse and significant health benefits. It reduces the risk of type II diabetes, cardiovascular disease, premature death, and preterm birth, and increases sleep duration.”University of East Anglia – Science Daily

“People living closer to nature also had reduced diastolic blood pressure, heart rate and stress. In fact, one of the really interesting things we found is that exposure to greenspace significantly reduces people’s levels of salivary cortisol — a physiological marker of stress.”

Because fresh outdoor air decreases the accumulation of the virus particles, supports the immune system, and decreases the risk of chronic diseases associated with developing a severe course with COVID-19, take advantage of these simple ways to decrease the risk of becoming severely infected with COVID-19. Get outside, and open your windows daily.

Does stress affect my immune system?

Multiple studies have shown the harmful effects of chronic or long-term stress (92, 93). “Stress occurs when life events surpass your abilities to cope. It causes your body to produce greater levels of the stress hormone cortisol” (94). When stress is limited to short spurts, cortisol can raise your immunity by limiting inflammation. But, when stress continues for an extended period of time, inflammation increases, white blood cells in your immune system are decreased, and depression and anxiety can set in, leaving you with an overworked, tired-out immune system that won’t be able to protect you efficiently from infections that cause illnesses like COVID-19.

To decrease chronic stress, Yale Health recommends the following (95):

  • Understand what you’re struggling against. For instance, during the COVID-19 pandemic, it is important to understand the facts about the disease in order to prevent or minimize infection.

  • Take the necessary precautions.

  • Keep up daily routines, even if some changes are needed.

  • Limit screen time.

  • Maintain contact with other people, even if your using FaceTime/Skype, phone calls, or text messages.

  • Stay active.

Can maintaining a relationship with God improve my immune system, even during a pandemic?

Many scientific have now shown a positive association between participation in religion and signs of healthy immune function, even in the aged and in those with serious viral infections such as AIDS (96, 97, 98, 99, 100).

Pray, trust and obey God, and experience His peace.

“I will instruct thee and teach thee in the way which thou shalt go. I will guide thee with Mine eye.” Psalm 32:8

Philippians 4:6, 7 “Be anxious for nothing, but in everything by prayer and supplication, with thanksgiving, let your requests be made known to God; and the peace of God, which surpasses all understanding, will guard your hearts and minds through Christ Jesus.”

Isaiah 26:3 “Thou wilt keep him in perfect peace whose mind is stayed on thee: because he trusteth in thee.”

1 Peter 5:7 “Casting all your care upon Him, for He cares for you.”


A properly functioning immune system brings protection. You can help to prevent or minimize infection with COVID-19 and similar infections by decreasing your biological age, avoiding harmful habits like smoking and drinking, eating a plant-based diet low in fat and low in free sugar, taking helpful supplements, getting enough Vitamin D, exercise, natural treatments with water and essential oils, getting adequate sleep, plenty of fresh air, properly managing chronic stress, and trusting in God.

“Beloved, I wish above all things that thou mayest prosper and be in health, even as thy soul prospereth.”3 John 1:2


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