Revealed: Two Experts Weigh In on How to Boost the Immune System

by Rachael Ling

I had the pleasure of interviewing two leading physicians in the “anti-aging and integrative medicine realm” with very different medical backgrounds, both coming to the same conclusion: the way we practice medicine must change. We need to be better advocates of our health, assess the entire picture, and not accept that we must settle for a certain quality of life because we are at the whim of genetics, getting “old,” or just downright bad luck. In this issue, we discussed ways to boost the immune system.

Over the next few months, we will introduce a series of topics that hold particular interest with the docs. For this topic, we’ll be providing a basic overview of the immune system and some simple ways to keep your immune system at its peak.

Quick background on the immune system

The immune system protects your body from outside invaders, such as bacteria, viruses, fungi, and environmental toxins. Although severely simplifying the intricate system that is “THE” immune system, for the sake of scope for this article, there are two main parts of the immune system:

  • The innate immune system you are born with. This part of the immune system starts at the level of the skin, mucous membranes, etc., that act as a barrier. If any of these barriers are compromised, pathogens can enter the system and cause disease. Our body “innately” knows to patrol, identify, and make quick orders of rallying the troops to destroy potential pathogens and return the host to health—cue adaptive immunity.
  • The adaptive/acquired immune system is developed over time and is established as the body creates snapshots from the innate system’s exercise of seeking and destroying. Consider it the “memory” aspect of the immune system. The adaptive immune system becomes more well-versed and can more effectively destroy a foreign invader in the future because the body has been there, done that. We can think of it as a catalog of antidotes for future infections. We also lump the immune response and memory from immunizations in this category. Immunizations teach the body how to respond to the illness in question without being exposed to it naturally.

There is a third “type” of the immune system worth mentioning called passive immunity. This type of immunity is “borrowed” from another source, and it lasts for a short time. For instance, monoclonal antibodies for treating covid patients acts as “passive immunity”. Another example would be the antibodies in a mother’s breast milk providing a baby temporary immunity to diseases the mother has been exposed to. Although transient, it does offer a baby/child some help in this arena since they are new to this world and lack the breadth of exposure to have a well-versed adaptive immune system just yet.

Key Terms

  • Mucous Membranes: Just as skin lines and protects the outside of the body, mucous membranes line and protect the inside of your body. Examples include: mouth, nose, eyelids, trachea (windpipe) and lungs, stomach and intestines, bladder, etc.
  • Autoimmune Disease: A condition in which the body’s immune system confuses its own healthy tissues as foreign and attacks them. Most autoimmune diseases cause inflammation that can affect many parts of the body. The parts of the body affected depend on which autoimmune disease a person has. Examples include multiple sclerosis, lupus, inflammatory bowel disease, rheumatoid arthritis, type 1 diabetes, psoriasis, and Hashimoto thyroiditis.
  • All-Cause Mortality/Morbidity: An umbrella term often used to reference chronic diseases/conditions and the associated deaths that arise directly or indirectly. More specifically, all-cause mortality is the death rate from all causes of death for a population in a given time period. Morbidity is a term associated with illness or conditions. Relevant to this article, some examples of common morbidities are heart disease, diabetes, and obesity.

What Impacts the Health or Vigor of our Immune System?


As we age, our immune systems become slower to respond and are not as robust as in our prime. The actual umbrella term for this phenomenon is “immunosenescence”. This less vigorous response can allow an invading pathogen time to overtake the host faster than the immune system can respond as it would have in the past. This scenario also sets the stage for opportunistic secondary infections and cancers. Even in the absence of preexisting chronic health conditions that may contribute to poorer disease outcomes, the immune system still goes through this natural decline associated with age.

Did you know that maintaining a consistent exercise routine assists in delaying or lessening the process of natural decline of immune function in the aging individual? (1)


The science and medical community acknowledge there is something to be said for genetic tendencies setting the stage for the potential expression of some disease states via the immune system, such as food allergies, certain cancers, or autoimmune diseases. Nevertheless, there exists conflicting consensus on the influence of nature vs. nurture specific to which individuals suffer the “fate” of said genes. However, the role genetics play in the immune system’s ability to fight off a good old-fashion winter cold remains a bit unclear. To date, research appears to give a mixed bag. Ultimately the concept of Epigenetics adds another layer of variables for either of the two scenarios. Epigenetics is the study of how environmental factors can switch on and off the expression of certain genes. Epigenetic changes do not alter your DNA sequence, but they can change how your body reads a DNA sequence and hence responds accordingly. This, of course, further complicates the understanding of how genes influence an individual’s health over a lifetime. Although we can’t choose our genes, we can make sure to provide the body a healthy environment so it has the tools to work as optimally as individually possible.

Chronic Disease

Chronic disease(s) have the potential to set the stage for an individual to be more susceptible to getting and staying sick by depleting immune system reserves, thereby leaving less than optimal resources to fight off illness adequately. Recently, there has been a heightened awareness surrounding certain disease-states that either create or are a product of a steady state of inflammation in the body. This interest stems from the discovery that inflammation in the form of a “cytokine storm” contributes to increased mortality rates in covid-19.

It then may be hypothesized that, if the body is already in a state of chronic inflammation induced by diseases or lifestyle choices, we may be tipping the scale in favor of increased covid-19 severity. This correlation provides another example of the importance of lifestyle management and taking the initiative to set our bodies up for success versus failure through anti-inflammatory nutrition, adequate exercise, and stress reduction.


It comes as no surprise for many of us that exercise has many positive effects on our health, including but not limited to cardiovascular health, improved body composition, increased insulin sensitivity, sleep, building and maintaining bone health, and stress reduction. The World Health Organization (WHO) has reported that physical inactivity has been identified as the fourth leading risk factor for global mortality, causing an estimated 3.2 million deaths every year. (2) A 2019 scientific review in the Journal of Sport and Health Science found that exercise can improve your immune response, lower illness risk, and reduce inflammation. Even exercise sessions lasting less than an hour at moderate-to-vigorous intensity increase the circulation of white blood cells and cause a rise in the production of natural killer cells. (3) All great reasons to not hit snooze the next time your alarm goes off for a gym session.

According to new data from the Centers for Disease Control, only about 23% percent of all U.S. adults get the recommended amount of both cardiovascular and strength training exercise each week. That is based off federal guidelines of 150 minutes of moderate intensity aerobic exercise, plus two sessions of muscle-strengthening exercise weekly.


We are what we eat and ate, plain and simple. If we chronically partake in food and beverage choices that tip the scale to a disease state, whether obesity, cardiovascular disease, diabetes, etc., we eventually suffer the consequences of our habits. That is not to say we can’t partake in occasional food and beverage indulgences; the key is to find a happy, healthy, realistic balance. In addition to calorie intake consideration, we should limit excessive consumption of processed and sugar-laden food and drink. Instead, our focus should be on fresh fruits and vegetables, lean proteins, dairy, and fiber-rich whole grains. By eating well, we provide the building blocks our immune system needs to function optimally, reduce inflammation, and maintain a healthy weight.

The American Heart Association suggests:

  • no more than 6 tsp (25g) of added sugar per day for women
  • no more than 9 tsp (roughly 36g) of added sugar per day for men.

To put that in perspective:

  • There are 4g of added sugar in 1 tbsp of ketchup
  • A single cup of low-fat yogurt can have an upwards of 40-50g of added sugar depending on brand
  • A standard 20oz sports drink can have close to 40g of added sugar.

Dr. Brookman believes those “sugar” suggestions should not only include added sugars but all sugars. He suggests taking the total carbohydrate number and subtracting grams of fiber to get the actual net grams of carbohydrates. 4 grams of carbohydrates = 1 tsp of sugar

Did you know that the sources of your food also contribute to your overall health? For example, studies have shown that wild-caught fish have a more favorable omega fatty acid profile than farm-raised fish. The same consideration can be made for eggs, dairy products, and animal proteins we consume. Not only are we what we eat– we are also what our food eats.

Metabolic Flexibility

Metabolic flexibility is the ability for a person’s body to switch “fuel” sources, such as carbohydrates and fats, during physically activity depending on the type of activity engaged in. You may find yourself asking, “Isn’t this something that just naturally occurs in everyone?”. Actually, no. Due to the ever-increasing prevalence of insulin resistance, there are many individuals who are not as metabolically efficient as the next person. Essentially, this creates an environment where the individual is unable to tap into their fat stores and use it as fuel. Even without a diagnosis of being pre-diabetic, or type 2 diabetes, many are toeing the line of being metabolically inflexible. How does one change this? Exercise assists in making muscle tissue more insulin sensitive while the type of exercise expands the ability to use the proper fuel. Timing and the type of food eaten before and after a workout are impactful, as is just better nutrition as a whole. Scientists are learning more about the role of metabolic flexibility and its direct impact on the health of one’s immune system. To date, there seems to be sufficient data pointing towards this being a variable that needs greater attention from an intervention standpoint specific to immune system function.

Gut Microbiome

You may or may not find it interesting that this is divided into a topic all its own. However, the fact that scientists have come to realize the gut comprises close to 70-80% of our immune system seems not only worth mentioning, but maybe even moving it to the top of the list as consideration for health interventions as a means to keep our immune system strong. A healthy gut contributes to a robust immune system, heart health, brain health, improved mood, circadian rhythm, effective digestion, and systemic inflammation regulation, and it may help prevent some cancers and autoimmune diseases. How? Through a symbiotic relationship with the vast microbes that call our guts home. These microbes assist in breaking down and assimilating foods, vitamins, and minerals we eat. They also play a huge role in neurotransmitter production (i.e., serotonin) and directly interact with essential aspects of our immune system. So, what does a healthy gut “look” like? It’s all about diversity and the balance of this diversity. How do we keep our guts healthy? Sorry to break it to you, but it is not as simple as purchasing the most expensive probiotics and BAM; everything is back in working order. That would be the equivalent of going out and buying random seeds packs and scattering them onto the ground without considering all the many variables they need to thrive. For example, if you toss seeds on top of hard clay, they will never take root. Or, if there is an overgrowth of weeds, the good guys never stand a chance to put down their roots and will be choked out by the bad guys. Or what if you had optimal soil conditions but never watered, fertilized, or gave them sun? If you are serious about getting your gut healthy, your first goal should be to find a health care provider who is well versed in “gut gardening”. However, in the meantime, here are some tips that everyone’s gut can benefit from:

Contributing factors that can disrupt the health of our gut:

  • Stress. Never fails.
  • Poor sleep habits.
  • Diet high in processed and sugar-laden foods.
  • High consumption of red meat
  • Excessive alcohol intake
  • Chronic use of antibiotics and/or steroids
  • Regular use of antiacid and heartburn medications.

In addition to avoiding the above habits, there are a few foods to consider adding to your repertoire to support gut health:

  • Fermentable foods such as kefir, sauerkraut, kimchi, etc.
  • A diversity of fiber. Fiber from different food sources provides important nutrients for the gut microbes. Examples include fruits, vegetables, lentils, whole grains, etc.
  • Foods rich in polyphenols

When we are stressed, whether physiologically or psychologically, the body responds by releasing adrenaline and cortisol. From an evolutionary standpoint, this is a perfectly natural and vital response to stress; however, it does not come without repercussions downstream, so to speak, when it becomes a chronic scenario. Essentially, long-term elevation of cortisol can suppress your immune system’s effectiveness in fighting off invaders by lowering the number of lymphocytes, including natural killer cells, and impairing proper communication amongst white blood cells. (5) Short-term suppression of the immune system should not pose any real detriment to the host in most overall healthy individuals. However, chronic suppression leaves the body susceptible to infection. Psychological stress can also indirectly affect the immune system as a person may use unhealthy coping behaviors to reduce their stress, such as drinking, smoking, and finding comfort in unhealthy food indulgences.


Not only can lack of sleep increase a person’s chance of getting sick, but it can extend the length of time in which an individual stays sick. Long-term sleep deprivation can also increase the risk of all-cause morbidity and mortality. How much sleep do you need to bolster your immune system? The National Sleep Foundation suggests that healthy adults need 7 to 9 hours per night. Babies, young children, and teens need even more sleep to support their growth and development. However, keep in mind that these are only guidelines, and these needs may decrease or increase depending on the individual. Did you know that chronically elevated cortisol levels during the day disrupt sleep, and lack of sleep further increases cortisol levels? It’s a vicious cycle! More reasons to reduce stress and ensure you are getting enough shut-eye.

Tips for creating good sleep hygiene:

  • Beware of blue light.
  • Disconnect from electronic devices.
  • Ensure your room is set on a comfortable temperature erring on the cooler side.
  • Avoid caffeine and alcohol close to bedtime.
  • Aim to maintain a set sleep and wake schedule.

Dr. Brookman suggests adding “no eating 2 hours prior to bed” to this list.

Doc’s Handbag: Supporting the Immune System With Supplements

  • Vitamin D – Know your numbers! Don’t guess, test. Current guidelines for “adequate” vitamin D levels are greater than/equal to 30 ng/ml. However, the docs argue that the lower-end range is “too” low. They prefer the minimum cut-off range to be 60 ng/ml. Multiple factors can directly impact an individual’s vitamin D levels – geographic location, age, ethnicity, sunscreen use, genetics, melanin, and diet. Your dosage will depend on your current vitamin D levels. For example, one person may benefit from a small dose of 1,000 IU, versus someone who is severely depleted may require an amount in the 20,000 range just to move the needle and increase their natural levels.
  • Quercetin – Dietary Sources include onions, grapes, berries, cherries, broccoli, and citrus fruits. Also found in high concentrations in elderberries.
  • N-Acetyl-L-Cysteine (NAC) – 600 mg, 2x/day
  • Glutathione – Choose liposomal form. Take 500 mg/day
  • Vitamin C – Choose liposomal form. Can take up to 1,000 mg every hour while awake if sick.
  • Zinc – 60-100 mg/day if sick. A lower daily dose works as a preventative. Take with food as higher doses of zinc can upset some people’s stomachs.
  • Xlear Nasal Spray – (grapefruit and xylitol). Can be used prophylactically morning and evening.
  • Nebulized H2O2 – dilute 10 mL of 3% food grade hydrogen peroxide in 100 mL sterile saline solution 1 ounce of 3% food grade hydrogen peroxide to about 10 ounces of sterile saline solution. Use 3 mL of the diluted mixture for each nebulization treatment. For an extra boost when sick, add 1 drop of 2% lugol’s iodine to each nebulizing treatment.

Natural doesn’t mean neutral! Please advise your physician on any contraindications and dosages prior to starting any new supplement. The docs also suggest only purchasing pharmaceutical grade supplements.


  2. Waxman A: Who global strategy on diet, physical activity and health. Food Nutr Bull 2004;25:292-302.
  3. Nielsen, A. R., and Pedersen, B. K. (2007). The biological roles of exercise-induced cytokines: IL-6, IL-8, and IL-15. Appl. Physiol. Nutr. Metab. 32, 833–839. doi: 10.1139/H07-054
  4. The Human Microbiome Project

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