Every moment of every day there’s a battle going on inside of us between our cells and what may be as many as 100 trillion microbes living in our bodies called the microbiome. These microbes — single-cell organisms such as bacteria (both friendly and not-so-friendly), viruses, fungi, parasites, and protozoa — are constantly in competition with our cells for resources and real estate, duking it out for sovereignty.
But despite the constant push and pull, the microbes we play host to are only harmful when they grow so numerous that they begin to take over.
The only thing standing between us and them? Our immune system.
A healthy, pumped up immune system is well-equipped to keep those trillions of internal microbes in check, and to contend with the microbes we come in contact with daily in our environment through the air we breathe and the food we eat. When our immune system is hampered and starts to lose ground, however, we get tired, weak, and may even fall ill. We also age more quickly when the microbes start to gain an upper hand.
Unfortunately, our modern world is ripe with threats that weaken our immune defenses and give microbes the advantage. Keep reading to get a glimpse of the impressive power your immune system wields, insights on how lifestyle and environment chip away at its resilience, and — the good news! — potent ways you can minimize those threats to your immunity and level the playing field.
Meet Your Immune System: Your Personal Department of Defense
To understand how vital it is for us to support our immune system in its fight against microbes, it helps to have a fundamental sense of how our body protects itself.
Our immune system is a complex network of organs (including the skin, bone marrow, thymus, and spleen), white blood cells, proteins, and antibodies. It has several jobs, including cleaning up metabolic debris from cell death and damage, and taking out our own cells that are turning into cancer.
Another, vital immune function: Defending against foreign invaders. When immune cells detect a microbe they’re not familiar with, they deploy defense troops to deal with it one way or the other. Just like in any regiment, there are different types of soldiers for different tasks.
Our innate immune system is our first line of defense. It functions as a physical barrier to unwanted outsiders, plus it sends out white blood cells to act as sentries, waiting to intercept and target anything foreign that comes through the door. And there are a lot of potential entry points: The mouth and nasal openings, lining of the entire intestinal tract, lung tissue, skin, and urogenital system (vagina, cervix, penis, bladder, and kidneys).
The innate immune system consists of:
- Natural barriers (skin and mucosa or mucous membranes) that prevent microbial entrance
- Various effector cells: white blood cells such as natural killer cells and phagocytes like macrophages and neutrophils that play a key role in pathogen destruction
- Antimicrobial peptides and proteins
- Various cytokines, protein messengers that help regulate inflammation and immunity
- Cellular receptors that sense and recognize a variety of microbial components
Then we have an adaptive immune system. Unlike the innate immune system, which goes after any and all general threats, the adaptive immune system is more specific and selective in its targets. It’s activated by exposure to pathogens — invaders it doesn’t recognize or know how to deal with — and it builds and relies on an immunological “memory” to enhance its response.
Fortunately for us, the immune system’s memory is old and vast. It evolved over millions of years from repetitive exposure to an enormous number of different microbes. For every trick that microbes developed to get past immune system barriers, the immune system developed countermeasures to match it that get hardwired into your genes.
Ultimately, the better your immune system “knows” a microbe, the better it is able to keep the natural aggressiveness of that microbe in check. A pathogen is just a microbe your immune system doesn’t know yet.
The adaptive immune system consists of:
- B cells: These cells roam the area like security guards on patrol, looking for microbes that are foreign. When they find one, they tag it with antibodies that inhibit the invader and make them easy targets for cells like macrophages (which eat them up).
- T cells: T cells directly kill cells infected by a foreign invader. They also rally the troops by sending out cytokines as messengers to the rest of the immune system to ramp up its response.
- Immunoglobulins (antibodies): These Y-shaped proteins are specific to each pathogen (thanks goes to our immunological memory). They lock onto the surface of an invading cell and tag it for destruction.
How Microbes Outwit & Outlast Our Immune System
Compared to the complex structure and function of our immune system, microbes are, well, basic. They have only one purpose: To make more microbes.
As long as microbes have access to nutrients and resources, they divide and divide, reproducing endlessly. It’s their only job, and they’re very good at it. (E. coli, for example, can divide itself into a million bacteria in just a few hours, which is why it can be deadly.)
The microbes that inhabit your body are host dependent — they must get the nutrients they need to survive from a host like you. That means your food is their food, but it also means that the cells that make up your tissues are also potentially their food. This explains why the highest concentration of bacteria in the body is in the large intestine, where there’s plenty of free food — your gut bacteria get all the leftovers that you don’t absorb.
The unrestricted growth of microbes only becomes significant if they get into your bloodstream and deeper tissues — which they are constantly trying to do. The organic molecules that make up your cells offer a treasure trove of nutrients that microbes can use to survive. Indeed, an “infection” is simply a microbe trying to gain access to the abundant organic molecules your body has to offer.
Many microbes specialize in invading living cells to gain the resources and nutrients they need to survive. It’s an ancient strategy they’ve been honing for billions of years. By infecting and pirating organic molecules and resources from larger cells, these intracellular microbes have both food and protection from the immune system as well as other bacteria and antibiotics. The infected cell might be weakened, but might not die — at least initially. Talk about easy living.
Every living organism on earth — plants, animals, and even mushrooms — harbor some cells infected with intracellular microbes. Your body is not excluded. Recent evidence has confirmed that even the healthiest among us harbor intracellular microbes in tissues throughout the body.
The only thing that keeps these microbes from consuming you from the inside out? You guessed it: Your immune system. But if immune system functions are disrupted and the microbes are allowed to proliferate, symptoms (like fatigue, brain fog, joint pain) and illness ensue.
It depends on which microbes are spreading as to what kind of symptoms or illness you suffer. In fact, an overgrowth of specific microbes have been linked to many degenerative conditions and fatal diseases; here are just some of the more compelling examples:
- Mycoplasma has been found in the joint fluid of those suffering from arthritis.
- A 2017 study from the UK detected an increase in specific bacterial populations in the postmortem brains of Alzheimer’s patients compared with brains of those without cognitive impairment, including bacteria specific to the skin, nose, and mouth.
- In 2016, researchers from Canada published a study showing a link between brain microbes and multiple sclerosis.
- Other research has found that around 20% of cancers may be the result of early life exposure to microbes (the HPV strain which causes cervical cancer is an example of this).
Based on this research and more, I believe it’s clear that microbes are at the heart of many of our illnesses and diseases — and, conversely, that keeping the immune system strong is imperative to maintaining wellness.
4 Modern-World Norms that Sabotage Immunity
In the past century, our planet and lifestyle have changed in ways that make things tougher for our immune cells to keep microbes from taking over, making us more prone to illness and accelerated aging. There are four main things we must defend against in modern life to help our immune system keep microbes in their place, factors which stress our cells and age them more quickly:
1. The Typical Western Diet
There’s no denying that what we eat today bears little to no resemblance to what our ancient ancestors ate many thousands of years ago — back when the human body was building the foundation of immunological memory. They foraged for fruit, nuts, and edible plants and herbs, subsisting mostly on a plant-based diet and hunting for the occasional meal of lean meat or fish.
Contrast that with the typical modern American diet, which is rich in refined carbs and sugar, and in fats from dairy, meat, and fried foods. What’s blatantly missing: Plant foods. In fact, only 1 in 10 Americans meet the recommended daily intake of at least 1½-2 cups of fruit and 2-3 cups of veggies, according to the Centers for Disease Control and Prevention.
This matters in part because we’re falling dismally short on phytochemicals, chemical compounds that plants use to neutralize threats or provide protection against stress factors like insects, pathogenic microbes, and environmental stressors like harsh climates. Plants also make specific phytochemicals to keep communication flowing between cells that facilitates proper functioning and good health. And because humans face many of the same or similar threats that plants do, we’ve learned how to gain many of their phytochemical defenses when we consume them.
All the refined carbohydrates (chips, bread, pasta, etc.) and saturated fats from dairy and meat we consume aren’t doing our immune system any favors, either. Excess carbs gum up the machinery of our cells and provide food for unfavorable microbes in the gut, fueling their overgrowth. And saturated fats from dairy and meat make cell membranes stiff, so they don’t do as well communicating with other cells.
2. The Blight of Chronic Stress
When we’re stressed — by our work, our kids, traffic, a constant stream of texts and emails — we go into fight-or-flight mode, releasing a cascade of neurochemicals and hormones, including adrenaline, which keep us on high alert and readies us to fight or flee. In prehistoric times, this system was activated infrequently, perhaps when a saber-toothed tiger surprised us from behind a bush while we were engaged in low-stress, all-day foraging.
Today, with the constant stressors, it’s as though we are running from the tiger 24/7. Chronic stress disrupts communication systems in the body, including hormones and the nervous system. If cells can’t communicate with one another, they can’t help each other. The immune system’s comms are especially vulnerable to the negative effects of chronic stress.
Most importantly, chronic stress disrupts sleep — and the body cannot repair itself without the downtime allowed by sleep. Too little sleep decreases production of cytokines that fight infection and inflammation, and research has shown that it also inhibits T cell function.
3. Exposure to Environmental Toxins
Millions of years ago, the only toxins humans really had to worry about were from the rare interaction with poisonous plants, mushrooms, insects, or other living creatures. Today, petroleum and coal burning release toxins into our air, food, and soil and expose us to elements we haven’t had enough time (think: millions of years) to evolve a defense against.
Having to contend with these new toxins is proving to wear down our immune system in a number of ways in both animal and human studies. For instance, research suggests exposure to dioxin, a chemical byproduct of industrial production and waste incineration that makes its way into the food chain, impairs T cell production and function.
Another study found that prenatal exposure to BPA (an industrial chemical used to make plastics) increased cytokine production and reduced the number of T cells. And exposure to PFOS — widely used in non-stick, fire-resistant, and stain-repellent products — led to reduced NK cell activity, antibody production, and B cell numbers. The list goes on.
4. The Tendency to Be Inactive
Prolonged sitting — something too many of us do thanks to the prevalence of desk jobs, cars, and cozy couches in front of the television — has been in the hot seat lately for its negative impact on immunity and overall health. This tendency toward a more sedentary lifestyle translates to lower levels of cardiorespiratory fitness, which has been associated with reduced immune response to vaccination and increased chronic low-grade inflammation. People who are less physically active are also more likely to report symptoms of upper respiratory illness and reactivation of latent herpes viruses such as Epstein-Barr (EBV) and herpes-simplex-virus-1 (HSV-1).
Experts point to a number of reasons for the connection between lack of movement and low immunity. For instance, it may be that inactivity means effector cells are less mobilized and so less ready to take the fight to infected cells. Lack of movement might also decrease the release of cytokines from skeletal muscles that help direct immune response toward an infection. Whatever the reasons, it’s clear that inactive folks are at an immune disadvantage.
6 Natural Ways to Outsmart Immunity Saboteurs and Boost Your Defenses
No one can live a completely stress-free, ultra-active life, nor can they eat perfectly every day (if ever). But there are some targeted and powerful ways to combat the immunity saboteurs of 21st century life.
All of the following defense tactics take the burden off our immune system, and lightening the load of our immune cells is one of the best ways to strengthen them and all cells.
1. Step Up Your Diet and Eat More Plant Foods.
While an always-perfect diet is impossible, better is totally doable. I advocate for a daily diet that’s at least 50% vegetables, is mostly made up of fresh foods, and has minimal grains.
The best choices are high-fiber — fiber feeds our good gut bacteria — and antioxidant-rich fare, like dark leafy greens, wild berries, fresh herbs, nuts, and legumes. Antioxidants help our immune system mop up free radicals, a metabolic waste product that damages cells.
In addition, you want to reach for phytochemical-rich fare to help boost your resilience with the plant’s immune system. Unfortunately, today’s cultivated edible plants don’t have nearly the amount of phytochemicals as their wild cousins, in part because modern food production has cultivated them to contain unnatural levels of carbohydrate (which our taste buds prefer) at the expense of protective phytochemicals.
Still, you should try to include fruits and vegetables that are particularly high in phytochemicals, such as:
- Cruciferous veggies like broccoli, cabbage, cauliflower, and Brussels sprouts
- Dark leafy greens like kale and spinach
- Bell peppers
- Mushrooms (shiitake, maitake, and oyster are potent immunity boosters)
- Fresh herbs (ginger and turmeric are especially powerful)
We need some fat, since some of the fat we consume makes up our cell membranes, which plays a key role in cell function. But not all fats are created equal.
Fats that are fried or saturated can stiffen or destroy our cell membranes. On the other hand, monounsaturated fats from things like olives, nuts, avocados, and canola oil are more flexible and enhance the cell membrane, and they’re relatively resistant to free radical damage.
Omega-3 fatty acids, found in salmon, sardines, flax, walnuts, and krill oil, are essential for healthy immunity. They have anti-inflammatory powers, and controlled inflammation helps fight illness, heal wounds, break down old or damaged tissues and more.
Cut way back on refined carbohydrates and sugar — a primary fuel source for gut microbes that facilitates overgrowth and microbiome disruption. The best tolerated grains include rice, quinoa, oats, barley, and millet, but consumption of grains in general should be minimized for optimal health, and particularly corn and wheat products.
Herbs are a great source of phytochemicals and antimicrobials. While you can’t get all their benefits from the herbs we typically cook with, it’s smart to include them as much as possible in food recipes and teas. But to truly harness the power of herbs, you have to supplement with a variety of preparations.
2. Add Herbal Supplements to Your Daily Routine.
Our paleolithic ancestors didn’t need to supplement with herbs because their foraged-food diet supplied them with a plethora of phytochemical-rich fare. (Not to mention, they weren’t facing the same level of toxins and stress we are today.)
For us 21st-century humans, however, taking herbal supplements delivers concentrated phytochemicals we’re not getting elsewhere. That’s because unlike today’s farmed plant foods, herbs haven’t been cultivated and bred for taste or mass production. Which means herbs may get us closer to replicating the phytochemical-loaded diets — and the health-giving results — that our ancestors enjoyed.
Herbal supplements might also deliver more phytochemicals than even an ancient foraged-food diet did: New technologies enable us to separate the phytochemicals from the bulky fiber of the plant and concentrate them in greater amounts.
- Herbs are powerful anti-microbials. All herbs contain antimicrobial elements, some more than others. That’s good news for all of us living organisms that are constantly invaded by intracellular microbes. When we consume the herbs, we can tap into plants’ sophisticated spectrum of phytochemicals to control microbes and boost our immune system with the plant’s natural defenses.
Good choices for herbs to use on a daily basis for an antimicrobial lift include: Japanese knotweed (also a great source of resveratrol, famed for healthy aging properties) and cat’s claw, an herb from the Amazon with thorns that resemble a cat’s claw (traditionally used to support cognitive function and protect joints).
- Herbs deliver potent antioxidants. Plants generate different types of antioxidants to protect cells from different types of free radicals. When we consume phytochemicals, we gain the benefit of that protection. All herbs generate cell-protecting antioxidants, but some that offer especially robust cellular protection include rhodiola, turmeric, gotu kola, and shilajit.
- Herbs facilitate clear cell communication. All our cells, not just immune cells, engage in dynamic dialogues in order to work best together. Plants use signalling agents similar to the ones we use, and when we consume phytochemicals from a healthy plant, it has the effect of balancing our body’s disrupted communication systems. Herbs called adaptogens are especially good for normalizing disrupted communications, Two of my favorite adaptogens are reishi mushroom and rhodiola.
3. Exercise More.
Aiming to get at least 30 minutes of moderate to vigorous exercise (brisk walking, jogging, swimming, hiking, etc.) is a great way to counter the immune damage done by sitting at a desk all day. For one, physical activity triggers the release of anti-inflammatory cytokines from muscles, and it helps modulate metabolic signals related to immune function, according to a review in the journal Current Pharmaceutical Design.
Exercise also stimulates blood flow and helps you work up a sweat, which flushes away toxic substances, viruses, and other debris from the body. It stimulates the secretion of endorphins, hormones that support good immune system functions. Plus, regular exercise triggers a build-up of adenosine, a key chemical that promotes sleep — and you have to have good sleep for cells to have down time to perform repairs and boost immunity. Speaking of…
4. Sleep Enough.
Remember, during sleep is when your body finetunes itself, and when cells can perform that all-important maintenance. It’s also a time for your brain to process any stressors you experienced that day, which will naturally help your immune system.
Getting regular sleep (going to bed and getting up at the same time) and adequate sleep (between 7 and 9 hours a night) is key. So be sure to power down electronics early on (blue light from screens suppresses melatonin, the hormone you need to feel drowsy) and practice good sleep hygiene — a dark, cool, quiet environment is best.
5. Don’t Let Chronic Stress Win.
Yes, you can meditate. Yes, you can do deep breathing. Yes, you can do some downward dogs. But you can also just walk. Walking is one of the most effective and easiest antidepressant/antianxiety activities there is. Plus, it’s free and requires no thinking (beyond where to go and what shoes to wear). A 15-minute walk is all it takes to normalize your adrenaline levels.
6. Cut Your Exposure to Environmental Toxins.
Every time you breathe or eat, you are essentially taking in toxins and microbes. So, while you can’t completely eliminate your exposure, you can lessen it.
Spend as much time as you can outdoors, for starters. And bring the outdoors in: Certain indoor plants act as natural air filters, removing immune-busting VOCs (volatile organic compounds) and toxic formaldehyde from the air (formaldehyde lurks and off-gases from carpet, paint, wood flooring treated with finishes, particleboard, and more). A study from NASA found that plants such the golden pothos, peace lily, palms, and ficus alli are also high on the list of natural filters.
Another easy trick: Open the window. This not only brings in fresh air but helps to let indoor toxins out. Many homes built in the 70s were made air-tight — too tight! — and don’t allow indoor pollutants to escape.
The Bottom Line
Your immune system goes to bat for you all day every day, defending against infection and illness, cleaning up your cellular messes, and more. But when your immune system goes down, it can take you with it, causing everything from little nagging symptoms like fatigue and brain fog to serious illnesses like Alzheimer’s and cancer.
Fortunately, you now have all of the basic natural tools you need to bolster your immune system and fortify its defenses against deteriorating forces. Put them to good use starting today so you can enjoy a long, healthy, resilient life.
1. Bethany Winans, et al. Environmental toxicants and the developing immune system: a missing link in the global battle against infectious disease? Reproductive Toxicology. 2011 Apr; 31(3): 327–336. doi: 10.1016/j.reprotox.2010.09.004
2. Christina M. Post, et al. The Ancestral Environment Shapes Antiviral CD8 T cell Responses across Generations. iScience, 2019; 20: 168 DOI: 10.1016/j.isci.2019.09.014
3. Yan H, Takamoto M, Sugane K. Exposure to Bisphenol A prenatally or in adulthood promotes T(H)2 cytokine production associated with reduction of CD4CD25 regulatory T cells. Environ Health Perspect. 2008 Apr; 116(4):514-9.