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11 Proven Ways to Make Your Immune System Stronger

There’s a lot of misinformation out there on how to strengthen your immune system. This article cuts through the baloney and focuses on science based facts.

These immune system improvement tips are designed to work together as a total lifestyle modification.

One single action might not provide a significant improvement to your immune system. However, done together, could provide a synergistic improvement to how your body protects itself from illnesses.

Table of contents

How do you make your immune system stronger naturally?

There are many natural ways to build up your immune system through diet and lifestyle changes. Eating organic fruit, fermented vegetables, grass-fed meat, and wild-caught fish is a start.

Also, getting plenty of quality sleep and reducing stress is helpful. However, one of the best ways to boost your immune system is the the consumption of probiotics and prebiotics in order to diversify the gut microbiome.

Eat vegetables to naturally boost your immune system

I have written similar articles that all touch on how to build up the immune system, but this article makes that the central focus. Here are the three articles that can provide additional context for some of the topics I’m going to cover:

The recent Coronavirus (COVID-19) has highlighted the importance of our immune system. However, if we didn’t have a strong immune system we would all die from almost any bacterial or viral infections.

Not just the coronavirus, but a strong immune system protects us from:

  • Pathogens (bacteria and viruses)
  • Parasites
  • Fungi
  • Cancer cells
  • Harmful substances from the environment
  • Antigens (foreign things the body doesn’t recognize as its own)

How does the immune system work?

Its a pretty complicated system and like most things biologically related, we are learning more and more about it every day. The immune system gets “activated” by the (foreign) things listed above when the body doesn’t recognize them as its own.

When we are exposed to the pathogen for the first time, our immune system makes a unique antibody to kill it. This usually takes time and why you get sick for a few days initially. Then, as your new antibodies proliferate and move in to destroy the foreign invader, you get better.

The beauty of our immune system is it saves the antibody in its immune system “memory bank” for the next time you need it. Then when you are exposed to the same pathogen, germ or virus again, the pre-engineered antibody instantly attacks it and you usually don’t even get sick, or if you do it’s very mild.

Building up your immune system can make it respond quicker

There is another part of our immune system is called the adaptive immune system. As the germs mutant and adapt, our immune system also adapts with new antibodies. It’s the eternal and war for survival within our bodies.

There’s also another subsystems within the immune system called the innate immune system. This one is a little simpler, harmful things that enter our body through the skin or digestive system are “eaten” by killer cells and phagocytes.

I’ll talk more about intermittent fasting later, but if you fast long enough to initiate autophagy, you can strengthen your immune system. The killer cells become very efficient at eating a lot of the bad things within your body.

If you want to get more into the nuts and bolts on the function of the human immune system I recommend this article on

Vaccines can make your immune system stronger

This article is going to primarily focus on the natural ways to boost your immune system. However, vaccines do work and they do save lives.

A vaccine is just an inactive form of a virus, just enough to stimulate a small immune response, but not enough to make you sick.

The body then builds antibodies for defense against the virus. So in the future, if you get exposed to a stronger, active form of the virus, your body already has the antibodies ready made to quickly move in and destroy the pathogen.

The problem is, since viruses mutate, you are only being protected from the specific strain that you were vaccinated for. That is why you have to get a new flu vaccine (shot) every year.

The CDC identifies the most prevalent strains for that particular year and we inoculate ourselves for those strains. You can read more about different types of flu vaccines here.

That is also why there has never been an effective vaccine for a cold (rhino-virus). The rhino-virus mutates too fast and the specific strain is never the same. Every time you catch a cold it’s a slightly different strain of the rhino virus.

Antibiotics don’t make your immune system stronger

Antibiotics only work for bacterial infections, not viruses. An example of a bacterial infection is Lime Disease. If caught early enough, antibiotics can work very well in treating lime disease.

Antibiotics do not work for viral infections and can even make things worse

Don’t self-diagnose, if you get sick get tested and let a doctor prescribe you the proper treatment. Excessive intake of antibiotics can contribute to developing antibiotic resistant infections.

“The emergence of antibiotic resistance is primarily due to excessive and often unnecessary use of antibiotics in humans and animals.”

Risk Factors for the Spread of Antibiotic-Resistant Bacteria

Antibiotics are the nuclear option. They kill all of your bacteria, both good and bad. That’s right, the beneficial bacteria that exist in our body is an essential contributor to a healthy immune system.

If you don’t read any more of this article, please skim down to the last section where I cover the gut microbiome. The gut microbiome, also referred to as the Human gastrointestinal microbiota, has a monumental impact on a properly functioning immune system.

proper hygiene supports the immune system
Proper hygiene and nutrition are essential for a strong immune system

There are ways to make the immune system stronger and faster

According to Google Trends, the “ways to build your immune system?” query is up +4,050%. The Coronavirus is not the first, nor will it be the last fatal virus that we’ll have to deal with.

To put things in perspective, here is a list of the major (recent) viruses that have led to major loss of life:

  • Ebola
  • Swine Flu (H1N1)
  • SARS (severe acute respiratory disease)
  • Avian (bird) flu (H5N1)

“Whenever the immune system deals successfully with an infection, it emerges from the experience stronger and better able to confront similar threats in the future.

Our immune system develops in combat. If, at the first sign of infection, you always jump in with antibiotics, you do not give the immune system a chance to grow stronger.”

Andrew Weil M.D.

Foods that strengthen the immune system

Foods are the best way to naturally build up your immune system. I will provide a short list of the best low-carb superfoods and also give some general suggestions.

I am a believer in eating a generally low-carb, sugar free diet with plenty of green leafy vegetables. Sugar is very unhealthy, especially refined sugar and processed foods. Sugar and the unhealthy fats found in processed foods lead to inflammation in the body. Inflammation is a foreign substance to the body and initiates an immune response.

The exception to my rule is fruits. Fruits in general are not keto friendly because of the high amount of fructose found in most fruits. But this article is not about the ketogenic diet.

Fruits contain a lot of prebiotic fiber and I’ll discuss more about that later. The primary way fruit strengthens the immune system is by providing antioxidants, polyphenols and micro-nutrients.

“Polyphenols play a vital role in the microbial community, as they have positive effects on the microbes. Simultaneously, these microbes promote the oxidation and degradation of polyphenols.”

Regulation of Immune Function by Polyphenols

You can read more about antioxidants here, but fruits reduce inflammation

Fruits also contain a lot of micro-nutrients that have been shown in numerous studies to support the immune system. You can read one of the studies for yourself here:

“A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection”

Cod liver oil supports the immune system
Cod liver oil contains vitamin D

Vitamin D deficiency affects approximately 50% of the entire world’s population! Consequently, many doctors are now increasing their recommendations for vitamin D supplementation to at least 1000 IU per day.

Ultraviolet sun light contacts the skin and we synthesize it into vitamin D3, which is the most natural form of vitamin D.

“Without vitamin D, only 10–15% of dietary calcium and about 60% of phosphorus are absorbed”

Vitamin D: The “sunshine” vitamin

Supplementing your diet with vitamin D, especially in the winter months when we are not exposed to the sun makes a lot of sense.

This study from the Feinstein Institute for Medical Research, Manhasset, NY, states that Vitamin D plays an important role in immune response. Deficiency is also associated with susceptibility to infection.

Here is a list of the most researched micronutreints that make the immune system stronger:

  • Vitamins D
  • Zinc
  • Vitamins A
  • Vitamins E
  • Folate
  • Vitamin B6
  • Vitamin B12
  • Iron
  • Copper
  • selenium
Airborne is just a multivitamin
Airborne is just a multi-vitamin

Airborne doesn’t boost your immune system any more than any other multi-vitamin

In 2008, the makers of Airborne settled a $23.3 million class-action lawsuit for false advertising. If you want to take a multivitamin that’s fine, I would recommend it, but don’t think Airborne is some magic immune booster.

After the lawsuit Airborne changed its marketing slogan. Now it (Airborne) doesn’t claim to be an immune system booster, it only claims to help support your immune system.

“It’s (Airborne) just a mixture of vitamins, herbs, and minerals. There is nothing particularly special about this mixture.”

David Schardt, senior nutritionist for the Center for Science in the Public Interest (CSPI)

Megadosing vitamins won’t help your immune system

With the exception of vitamin C, taking large doses of vitamins can actually be counter-productive. More is not better because we need the proper balance of nutrients in our bodies to make our immune system function properly.

In 7 January 2020, this non-randomized trial showed that of the 252 students treated with a high dose of vitamin C, 85% experienced a reduction in Coronavirus symptoms. Vitamin-C supplementation is recommended and is one of the the most powerful antioxidants.

Homeostasis (balance) is usually the best formula

Zinc supports immune system function

Excess sleep and exercise can even be harmful. Balance also applies to vitamins and minerals such as zinc. The biomedical community has known for quite some time that zinc provides support for the immune system, but don’t over-dose.

“Zinc supplementation decreases incidence of infections in the elderly”

PubMed, PMID: 17344507, Ananda S Prasad, MD, PhD

Zinc deficiency in humans is a huge problem and affects over two billion people worldwide. Zinc is also hard to absorb in your diet, excess phytates, antibiotics, calcium and iron can block its absorption.

Phytates (phytic acid) are found in whole grains, legumes, nuts, cereals, corn and rice.

“The upper limit of dietary zinc intake should not exceed 25–40 mg/day. The RDA for zinc in adults is 11 mg/day for men and 8 mg/day for women.”

Zinc: dietary intake and impact of supplementation

Which form of Zinc supplementation is the best?

That’s a good question. From my research, the best forms of zinc come from:

  • picolinate
  • aspartate
  • citrate
  • gluconate

This study recommends 10-12 milligrams a day of zinc aspartate. This study recommends zinc picolinate. Additionally, this study shows that zinc gluconate and zinc citrate are almost equally bioavalable.

Zinc oxide and sulfate seem to be the least bio-available forms of zinc.

Vegetarians beware, your zinc levels might be low

Vegetarians get a significant amount of protein from legumes. Legumes contain zinc blocking phytic acid, so they (vegetarians) might not be getting enough zinc.

“Relatively small amounts of animal protein can significantly improve the value of a legume-based meal as a source of zinc.”

Effect of protein level and protein source on zinc absorption in humans.

Strengthening your immune system is like a suite of armor

armor to support the immune system
Strengthening your immune system is like putting on a bullet proof vest

Naturally boosting your immune system is similar to a policeman wearing body armor. It gives him protection from attack and improves his odds of survival.

“One of the best ways to make your immune system stronger is with a healthy diet, diverse microbiome, exercise, get some sun (vitamin D), intermittent fasting, getting a good nights sleep and leading a healthy lifestyle.”

Robert Bryant, Ketogenicinfo

Eat vegetables to keep your immune system strong

Vegetables provide some of the same benefits as fruits without the extra sugar (fructose). Green leafy vegetables are particularly helpful in strengthening the immune system. They provide a lot of important vitamins, minerals, phytonutrients and prebiotic fiber.

Remember my analogy that our immune system is at war with a constant bombardment of viruses, germs and pathogens. You have to keep your soldiers well fed if you want them to win the war.

Intermittent fasting can renew your immune system

This is where two previously written article tie in. The article about intermittent fasting and about increasing your life expectancy and healthspan.

Intermittent fasting can have massive positive effects on a healthy immune system. A recent study published in the New England Journal of Medicine shows:

“Evidence is accumulating that eating in a 6-hour period and fasting for 18 hours can trigger a metabolic switch from glucose-based to ketone-based energy, with increased stress resistance, increased longevity, and a decreased incidence of diseases, including cancer and obesity.”

Effects of Intermittent Fasting on Health, Aging, and Disease

A 72 hour fast can have a significant impact on boosting your immune system

According to additional research, fairly long term fasting can actually regenerate the entire immune system! Immunosenescence is the reason elderly people are more susceptible to disease. Their immune system gradually deteriorates with age.

“Immunosenescence refers to the gradual deterioration of the immune system brought on by natural age advancement.”


Efficient white blood cells (lymphocytes) are essential for a strong immune system

This study indicates fasting lowers white blood cell counts which triggers the immune system to produce new white blood cells. After the fast, according to Professor Valter Longo, re-feeding initiates tissue regeneration.

The challenge is that the study shows it can take as much as 72 hours of fasting to initiate this immune Modulation of Stem Cells and Regeneration.

There might be ways to make it faster however, entering ketosis sooner might be able to shorten the time frame. Here is a method to speed up the keto process and get into ketosis within 24 hours. It seems actually being in the state of ketosis is part of the process of stem cell regeneration.

A good night sleep is good for the immune system

This one has been around seemingly forever. When you got sick your grandma told you to drink plenty of fluids and get some rest (bed rest). There is strong science behind this. When you are in deep sleep the body heals itself.

Cytokines are a type of signaling protein that helps regulate your immune system

Cytokines are important in the fight against infection and inflammation. Lack of adequate sleep dysregulates cytokine secretion and their signaling networks. states that insufficient sleep can make the flu vaccine less effective. This study I found on the US National Library of Medicine states:

 “Sleep appears to preferentially promote the pro-inflammatory cytokine production important for the mounting of adaptive immune responses”

Sleep and immune function

We have to make sleep a priority and reduce stress in our life. Wind down and relax before bed and turn off all electrical devices at least 30 minutes before you put your head on the pillow.

The serenity prayer has helped me over the years. Excessive worry is one of the leading contributors to poor sleep. Worrying about things you cannot control is a reoccurring problem in modern society.

“God give me the serenity to accept things which cannot be changed; Give me courage to change things which must be changed; And the wisdom to distinguish one from the other.”

Karl Paul Reinhold Niebuhr

Exercise can help you sleep and improve immune system function

Have you ever physically worked your tail off outside in the hot sun? If you have, you probably slept like a baby that night. Moderate (not extreme) exercise is the key.

This study on PubMed shows that exercise can improve vaccination effectiveness, boost T-cell production and increase killer cells in the immune system.

“Long-term moderate aerobic exercise elicited significant improvements in sleep, quality of life and mood in individuals with chronic primary insomnia.”

Effects of moderate aerobic exercise training on chronic primary insomnia

Here are the results from yet another interesting study I found on PubMed:

“There was a significant increase in total sleep duration, sleep efficiency and sleep onset latency in group (A) after 6 months of aerobic exercise training.”

Aerobic exercise modulates cytokine profile and sleep quality in elderly

Your gut microbiome are the soldiers fighting to make your immune system stronger

Immune boosting kefir

Last but certainly not least is the human microbiome. I wrote an entire article on this subject geared more to improving digestive health that I encourage you to read.

A healthy, diverse microbiome is probably the most significant booster to your immune system.

I say “probably” because the science is still emerging. There are literally billions of bacteria in our intestinal system. Biochemical scientists are still trying to figure out what bacteria does what, when and how.

To say the study of the human intestinal microbiome is emerging is an understatement

You will hear more about this in the future. Someday in the future you will likely see a doctor that specializes in the human gut microbiota when you are sick.

He will then bio-engineer a specialized strain of beneficial bacteria that he will seed into your intestinal tract. That will allow your own immune system to kill the pathogen.

What we know however, is that our intestinal flora (gut microbiome) exists in our body and we have an important symbiotic relationship with them.

We nurture them by introducing them into our body and feeding them prebiotic fiber. In turn, they help out our body in a multitude of ways. One way is to make our immune system stronger.

Eat fermented foods to strengthen your immune system

The video above is about probiotic loaded kefir. I encourage you to eat fermented food and drinks to increase your gut microbiota. Here is a list of the best superfoods to eat for over-all good health

The gastrointestinal tract (GI) is home to the largest density of beneficial bacteria (gut microbiota). T cells are found in the GI tract and develop from signals derived from the microbiota. T cells are immune system lymphocyte cells that protect the body from pathogens and infections.

The body is much more complex than what we thought in the past. Our brain, nervous and endocrine systems and organs all work together in synergy. The microbiome performs a vital function in this multi-directional communication interaction.

Our little bacterial friends help everything work together

This is called the gut-brain-axis and this might be the key to to making our immune system stronger and more efficient.

The diet, immune system and microbiota are critical regulators of this complex and interdependent network. If you want to read more about this complex system as it’s related to immune system function I encourage you to read this article :

Role of the Microbiota in Immunity and inflammation

probiotic supplements improve immune response
Probiotic supplements

Probiotic supplements are never as good as naturally fermented foods

Most store bought probiotics are good, definitely better than nothing. However, are we sure they are still living beneficial bacteria? How long have they been sitting on the store shelves? Will they survive in the stomach acids long enough to reach the intestinal tract?

When you ferment the vegetables yourself, you know they are alive. Additionally, if you eat fermented vegetables you are also adding prebiotic fiber to your diet.

Remember, for a diverse microbiome you have to give your beneficial bacteria food. Probiotics flourish by consuming prebiotic fiber and resistant starches.

So yes, it is possible to improve immune system function


I have shown you the science, yes some of it is still emerging, but if we take active steps we can lessen the chances that we get sick. If we do get sick our immune system will have the support it needs to fight the infection and give us better odds of survival.

Robert Bryant

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