Not far into my clinical residency, I started to notice something: while nearly everyone who came to see me seemed to realize the importance of maintaining a healthy immune system, almost no one knew what that actually means or had any idea where to start. I get it, though; I do. Immunology is a notoriously complex area of inquiry that has, in some ways, baffled top scientists for decades. How to boost your immune system is not a simple topic.
This is due to the fact that there are a lot of details, a lot of exceptions, some rather surprising facts and, to top it off, our knowledge of the immune system is constantly evolving. In other words, if “most moving parts” were a competition, Immunology might very well take top prize.
Fortunately for we mortals, it is not necessary to know all of the immune system’s intricacies in order to strengthen ours against sickness. As I explained to my clinic patients, the brain-bending topic of immune health is, in fact, quite beautiful in its simplicity if you know a few basic tricks.
You can get immune system booster supplements, but below, I’ll be giving you a brief overview of the immune system, touching on some common immune disorders, and presenting you with my favorite science-backed methods for strengthening yours so that you can better protect your own health and the health of your loved ones.
Table of Contents
What is the Immune System and How Does it Work?
The immune system is exactly that: a system. Stripped to its essence, the immune system is an evolving and well-orchestrated team effort, involving many different players who work together to provide a powerful defense against invaders.
These players can be divided into roughly two groups: (1) the innate immune team, hard-wired to protect us against everyday invaders and our first line of defense (something all animals just naturally seem to have), and (2) those who are part of the adaptive immune team (a defense system which can, as its name suggests, adapt to protect us against almost any invader) (Sompayrac, 2019).
The complex “Team Immunity” is made up of cells in your blood, skin, bone marrow, tissues, and a variety of organs that – when all is humming along as it should – protect our bodies against potentially harmful infectious critters such as viruses and bacteria while mitigating the cellular damage caused by noninfectious agents such as sunburn, according to the National Institutes of Health (NIH). Much like Goldilocks, we want an immune system that is neither under- nor over-reactive, but just right.
While I could write for days by digging into the aforementioned details of immunology, here we will focus on the aspect of immunity that is both nearest and dearest to my heart and what I consider to be the cornerstone of good health and the immune system’s MVP: the gut.
What Does the Gut Have to do with Immune Health?
Quick, if I were to ask you what’s the single most important thing you can do to stay healthy this year, what would you say? No, I’m afraid it’s not “wear my hat and mittens when I go outside,” in spite of what your grandma might’ve told you. But if “nurture my gut” is what came to mind, that’s great! You’re onto something. In fact, your gut, many experts agree, might as well be synonymous with “immune system” due to the enormous number of immune cells it houses.
Part of our innate immune system, the mucosal lining of the gastrointestinal tract provides a natural physical barrier, preventing the entrance of harmful organisms into our bodies (Mahmoudi, 2016). Historically, the digestive and immune systems were viewed as entirely separate entities. Today, however, we know that the gastrointestinal (GI) and all other organ systems are very closely linked. In fact, it is getting clearer all the time that everything from acne to vitiligo can be caused by imbalances in the microscopic life that calls our gut home (Knight, 2015); likely, a result of intestinal hyperpermeability (aka “leaky gut”) and the subsequent inflammation brought about by an immune system that’s off-kilter.
Simply put, an unbalanced gut equals a suboptimal immune system which, in turn, translates to an increased likelihood of developing illnesses of all types, both chronic and acute.
Understanding Immune Dysfunction
As Lauren Sompayrac explains in my favorite immunology primer How the Immune System Works, the immune system generally does a pretty awesome job at defending us (2019). Sometimes, however, mistakes get made. One very important example of an immune system gone rogue is autoimmunity.
The main concept here is inflammation. Inflammation is, in fact, a good thing and is part of your immune system’s job description. When your doctor talks about inflammation, what they are usually talking about is the process our body undergoes as it fights things that are threatening it such as infections, injuries, and toxins in an attempt to heal itself.
Now, think back to the last time you cut yourself. As part of the very natural and necessary process of inflammation, your immune system released antibodies and proteins, as well as drastically increased blood flow to the damaged area, in a cascade of events that can last for several hours to several days, depending on the severity of the cut. This is known as acute inflammation and will, if everything goes as it should, cease once our immune system has gotten the inflammation under control.
But imagine for a minute that your immune system, once it had done its job, got confused and kind of just kept going, destroying not only the invading bad guys but the healthy tissue, as well. This can happen, for example, with a virus. Confused and on a rampage, the immune system, long after the bad guys are out of the picture, continues fighting its war, leaving our bodies in a continual state of high alert. Instead of resetting to fight the next war like it should, it goes on fighting the first one forever, even though the enemy is long gone. In a nutshell, it can no longer distinguish between self and non-self; this is the definition of autoimmunity.
This chronic inflammation will have a detrimental effect on your tissues and organs over time. A few common examples of autoimmune disease are inflammatory bowel diseases (IBDs) such as crohn’s and ulcerative colitis, Hashimoto’s, multiple sclerosis, lupus, rheumatoid arthritis, and Type I Diabetes, but there are many, many more. In fact, according to the American Autoimmune Related Disease Association (AARDA), it is estimated that 50 million Americans have an autoimmune disease, resulting in an enormous cost burden on our country’s taxpayers.
Although the exact triggers of each of the more than 100 autoimmune diseases are not yet known, what is known is this: to develop an autoimmune disorder, you need three things – a genetic predisposition, an unbalanced immune system, and some sort of environmental trigger, be it bacteria, a virus, hormones, pesticides, or something else.
Knowing this, you can see why the health of your gut is paramount when it comes to protecting you against the onset of an autoimmune disorder, and we’re here to help.
Tips for Optimizing Your Immune System – Naturally
As Lauren Sompayrac explains in my favorite immunology primer How the Immune System Works, the immune system generally does a pretty awesome job at defending us (2019). Sometimes, however, mistakes get made. One very important example of an immune system gone rogue is autoimmunity.
The main concept here is inflammation. Inflammation is, in fact, a good thing and is part of your immune system’s job description. When your doctor talks about inflammation, what they are usually talking about is the process our body undergoes as it fights things that are threatening it such as infections, injuries, and toxins in an attempt to heal itself.
Now, think back to the last time you cut yourself. As part of the very natural and necessary process of inflammation, your immune system released antibodies and proteins, as well as drastically increased blood flow to the damaged area, in a cascade of events that can last for several hours to several days, depending on the severity of the cut. This is known as acute inflammation and will, if everything goes as it should, cease once our immune system has gotten the inflammation under control.
Nutrition and Supplementation
Many people interested in naturally boosting their immune systems are starting out by paying attention to their diets, and rightfully so. The food we put into our bodies can serve as either the strongest medicine or the slowest poison and we know today that our eating patterns can help to balance the gut, boost the immune system, and put the brakes on inflammation or, conversely, completely short-circuit our systems altogether.
Fortunately, researchers have begun revisiting the topic of medical nutrition therapy for many disorders, a logical progression following the realization that the food we eat is capable of triggering cascading events within our bodies, both positive and negative, and that our immune system (and its ability to modulate inflammation) is, as I mentioned above, tightly interconnected with our digestive system.
Simply put, your body, including your immune system, runs on the fuel you put into it. This is common sense, right? What many people don’t realize, however, is that the health of our immune system is pretty much synonymous with the health of our gut, and that what we leave out is every bit as important as what we put in.
In fact, I’d argue it’s even more so.
When it comes to boosting your immune system, if you do nothing else, following through with just these two things will give you the biggest bang for your buck.
- Eat FOOD. Far and away, the absolute best thing you can do for your gut health is to stop eating things that aren’t actually food. Was it created in a laboratory? Does it have an ingredient list comprised of anything other than simple, whole foods? Toss it.
- Eliminate (or, at the very least, drastically reduce) refined carbohydrates. We were not meant to take these in. A body given a steady stream of sugary junk and processed grains is a chronically inflamed body, and this is what you want to avoid.
Try your best to focus on nutrient-dense, whole foods; high-quality (i.e. free-range, naturally-fed) protein sources; sprouted, gluten-free grains; brightly-colored fruits and vegetables; and be super-liberal with herbs and spices, all of which can be considered nutritional superstars. Where possible, choose organic and non-GMO, and make every attempt to eat locally and seasonally. This not only gives your body the best of what nature has to offer but will save money, too.
Just like you wouldn’t put cheap, garbage-filled gas into a 200K sports car and expect it to run smoothly forever, you can’t put garbage into your body and expect it to serve you well over the long term.
[As an aside, if you haven’t already, consider picking up a copy of the book I most often recommend to both patients in-clinic and the college students I teach: Michael Pollan’s concise book Food Rules: An Eater’s Manual. Of all the books on the subject of nutrition that I’ve read over the years (and as a nutrition doctor, I’ve read hundreds), this one best sums up the very basic things you can do to maintain a normally functioning body – beautifully, elegantly, and simply.]
For even greater benefits, try fasting.
Specific Immune-Boosting Foods
OK, so aside from the most basic nutritional ground rules as outlined above, what are some of the specific foods we can add in that have been scientifically shown to boost immunity?
Here are some of my favorites, in no particular order:
- Citrus fruits, such as oranges, lemons, grapefruit, and limes.
- Cruciferous vegetables, such as cauliflower, cabbage, kale, bok choy, broccoli, and Brussels sprouts.
- Alliums; think “bulbs”, like onions, garlic, shallots, leeks, chives
- Brone broth; homemade is best, but there are many good-quality ones available for purchase, as well
- Poultry; preferably, free-range and organic
- Pomegranate (fresh, as 100% juice, or even the extract)
- Nuts and seeds, especially walnuts, almonds, Brazil nuts, and pistachios
- Mushrooms, such as button, reishi, lion’s mane, or shiitake
- Coconut oil; cook with it, add it to your coffee, or even mix it with nut butters and eat it off the spoon
- Manuka honey; even more than regular honey, manuka has been found to have immune-boosting qualities (be sure to buy it in glass containers as harmful chemicals from plastics can leach into the honey)
- Fermented and cultured foods such as kimchi, kombucha, sauerkraut, yogurt, or kefir; these will give you much-needed probiotics
- Ginger
- Dark chocolate
- Green tea
What about supplements?
Evidence is mounting that dietary supplements are not only useful when it comes to boosting our immunity, but desirable when compared to medications due to their status of “generally regarded as safe” (GRAS) by the U.S. Food and Drug Administration. Good immune system booster supplements will tell you exactly what’s in them and what benefits they will be giving you.
Using such things as turmeric for inflammatory skin conditions such as psoriasis in place of the medication that is ordinarily prescribed, for example, equals an effective therapeutic regimen with little to no side effects, a win-win for those preferring a more natural approach.
Many of the key nutrients for boosting immune health can be found in high-quality supplement form. Here are some of the most evidence-based to date:
Vitamin D – All the most important immune cells in your body have receptors for this vitamin and people with immune conditions, particularly autoimmunity, would do well to supplement with it. In fact, scientists at the University of Copenhagen found that vitamin D is so crucial to activating our immune defenses, that our killer T-cells won’t even activate without it.
Turmeric – An age-old spice with proven immune-boosting power. Coming from the root of Curcuma longa (a member of the ginger family), turmeric contains many substances, but one group, curcuminoids, have been shown to have the greatest health-promoting benefits. Shown to be antibacterial, antiviral, and antifungal, bright yellow curcumin (“the golden nutraceutical”), in particular, has been well-studied and is known for its positive effects on many of the body’s functions, including maintaining a healthy immune system.
Piperine – The major active component of black pepper, piperine has been shown to increase the bioavailability of curcumin by a whopping 2000%! For this reason, supplements often contain them both.
Garlic Extract – One of the most powerful immune-boosting plants on earth, this study found that participants taking garlic every day had significantly fewer colds than the comparison group and that those who did get sick recovered faster, with an overall finding that the results were “highly significant in favor of the supplement as a cold preventive.”
Zinc – Deficiency in this well-known mineral can cause growth retardation, decreased testosterone, cognitive impairment, and severe immune dysfunction, among other things. In fact, as this study found, during zinc deficiency our immune system is flat-out reprogrammed.
Echinacea Purpurea – When the inevitable seasonal cold hits us, many people turn to time-tested herbal remedies that can help clear congestion, soothe our sore throats or swollen nasal passages, or even reduce inflammation and fever. A group of wildflowers in the daisy family and native to central North America, echinacea’s roots have been shown to stimulate the immune system, inhibit inflammation, and reduce pain (Willoughby, 2016).
Elderberry – Another ancient plant with modern-day applications, the berries and flowers of this plant have been used for thousands of years for both culinary endeavors in the form of juice, wine, liqueur (including my favorite, St. Germain), syrup, or jam as well as medicinally. It can be consumed daily throughout cold and flu season and has been shown to significantly reduce cold duration and symptoms, being especially prized for its effects on respiratory health. Elderberries likely help due to their concentration of antioxidant and anti-inflammatory flavonoids, vitamins, and anthocyanins, the cell-protective compound that gives them their lovely purplish hue.
Ginseng – Another root that has been used for eons for its immune-boosting properties, ginseng is a superstar in Traditional Chinese Medicine (TCM), and it’s easy to see why. This study, for example, saw a near-doubling of natural killer cell (NK) activity level in volunteers given a daily dose of ginseng alongside their usual flu vaccine.
NAC (n-acetyl cysteine) – This amino acid reduces inflammation by increasing glutathione, a powerful antioxidant and anti-inflammatory, in the body, essential nutrients for fighting cellular damage and optimizing immune function. In one study, elderly subjects receiving supplemental NAC daily experienced significantly fewer flu-like episodes and days in bed than did the control group and significantly fewer developed symptoms despite the rate of infection between the two groups being the same. In another, daily NAC lowered oxidative stress and decreased inflammatory lung damage in those with pneumonia.
Olive Leaf Extract – After more than 23 years of living and cooking in the Mediterranean, I am a devoted advocate of all things olive. Of course, by now everyone knows about the incredible benefits of the extra-virgin oils and fruits themselves, but not everyone knows that the leaves, too, have been used medicinally for millennia. Olive leaf extracts (OLEs), which are now showing up in supplemental form, contain higher amounts of the healthful polyphenols than the olives and have been shown to modify healthy human immune response by exerting cardioprotective, antioxidant, and anti-inflammatory action.
Other star players include vitamin A, vitamin C, vitamin E, magnesium, selenium, beta-glucan, larch arabinogalactan, and oregano oil, as well as some lesser-studied but promising herbal supplements such as TCM’s astragalus, among others.
IMPORTANT: never start supplementing with any nutraceutical before talking with your doctor. The importance of ruling out undetected health problems cannot be overstated. Some supplements react badly with a variety of medications and many are contraindicated for people with certain conditions, including autoimmune diseases or even those experiencing perfectly normal pregnancies or breastfeeding. Remember: just because something is natural does not mean that it is automatically safe for every situation.
Stay Hydrated
As you might have guessed, good hydration is one of the key components when it comes to supporting the body’s immune system, our best defense against sickness, and simple tap water can be a very effective tool to keep you feeling fantastic year-round. In a well-hydrated state, our lymphatic system – think of it as our drainage and sewage system – can do its job effectively. This means that toxins, wastes, and unwanted materials will be more quickly and efficiently removed.
Exercise and Movement
If you’re reading this, you probably already know that regular exercise is recommended for just about everything, from keeping you in great physical shape to lowering your stress to simply clearing your head, for one very good reason: it works. Not surprisingly, regular exercise is recommended for maintaining a healthy immune system too. Researchers have found that regular exercise lowers your risk not only of developing one of the chronic diseases you hear so much about (like Type II Diabetes, heart disease, and obesity), but viral and bacterial infections, as well, according to a recent review published in Frontiers in Immunology.
For even greater immune-boosting benefits, exercise outdoors as often as you can. Spending time in nature comes with lots of proven benefits, including mood modulation, reducing inflammation, lowering blood pressure and, yes, supporting our immune system health. You’ll get a boost in Vitamin D, too, which plays a key role in how well your immune system functions.
Stress and Immunity
If you want a healthy immune system, the importance of a good stress-management program cannot be overemphasized. Continuous stress leads, quite literally, to near-constant suppression of your immune system which is the exact opposite of what you want, right?
Many people swear by yoga to keep stress at bay, and for good reason. One study, for example, found significant reductions in stress, anxiety, and all psychological health measures in the yoga group compared to the control group over the 16 weeks of the study’s duration. Similar findings have been replicated time and again and, today, no one doubts yoga’s stress-reducing benefits.
But what if yoga isn’t your thing? That’s o.k.! (Confession: it isn’t mine, either.) Research shows that any focused activity you choose, be it sudoku or putting together Lego sets with your kids, will lower detrimental stress hormones.
Other tried-and-true stress reduction weapons include meditation, getting a massage, practicing ‘mental hygiene’, learning a new language, taking up a musical instrument, and watching things that make you laugh.
For a more detailed understanding of how stress obliterates your immunity and what you can do to counteract it, see this article about your two nervous systems.
Best Practices for Healthy Living
Conventional healthcare practitioners have (finally!) begun to see the value of ancient remedies and have begun focusing on lifestyle changes as a first line of defense.
If you’re in the market for a straightforward DIY Immune-Boosting Plan, here are a few proven things you can do to ramp up your defenses: maintain a healthy weight, make love, get lots of natural sunlight, drink alcohol in moderation, don’t smoke, and eat dirt (yes, you read that correctly).
The Importance of Sleep
Studies have shown that lack of sleep can indeed negatively affect your immune system. In fact, there is solid evidence that not just the quantity but the quality of sleep matters, with people falling into either category – i.e. not enough sleep or sleep that is less than ideal – being more likely to pick up a cold after exposure to a virus.
To add insult to injury, people low on sleep recover more slowly from an illness than their well-rested counterparts. On the other hand, however, the reverse holds true. This study, for example, found that enhancement of sleep during an infection appears to promote host defense and that, “indeed, sleep affects various immune parameters, is associated with a reduced infection risk, and can improve infection outcome and vaccination responses.”
Convinced? Good. Aim for 7-8 hours of high-quality sleep each night. For even more benefits, make a habit of getting up and going down at the same times each day. Your immune system will thank you for it. Getting into regular sleep habits is also great for maintaining your energy level.
The Takeaway
As you have seen, the health of your immune system is largely in your hands. Leading a healthy lifestyle that includes a high-quality diet, lots of movement, plenty of fresh air and sunshine, fun and relaxation, restful sleep, and a solid stress-management plan is your best bet when it comes to protecting your health.
Whether you decide to start with just one of these tips or tackle a few at a time, any step you take towards strengthening your immune system will pay dividends for years to come by increasing not just your lifespan but your healthspan, too.
- Exercise and Immunity: Which Form is Best? - May 9, 2023
- How Does Zinc Affect the Immune System? - May 9, 2023
- How Stress Affects Your Immune System - May 9, 2023
