Journalism has given me many surprises over the years. Few compete with this sentence: Do not boost your immune system. C’mon, really? What would cause me to urge you to ignore all the accepted wisdom and powerful marketing aimed at having you boost your immunity? Because the actual science tells a very different story. The immune system is much less about exercising power than it is about finding balance. You can help train and maintain it. Here’s how.
What Is the Immune System?
Our great defense system helps ward off the most dangerous of invaders.
We live in a sea of organisms. Bacteria, viruses, parasites and other life forms great and small pave our surroundings, cover our skin, share our gut. Most of them mean us no harm. The job of the immune system is to keep us healthy in the midst of this challenging, complex environment.
It is a common misconception that the immune system goes to war with every foreign organism. That would lead to scorched earth, nuclear winter. Instead, the job of the immune system is to take stock, monitor, assess and judge potential threats. Ideally, the immune system would find a cooperative existence with the many microbes with which we share our bodies and the planet. But if an invader is deemed a threat, the immune system has a narrow job: destroy the threat while doing as little collateral damage as possible. This response from the immune system is called “inflammation.”
Inflammation can be a violent affair, causing an outpouring of poisonous, deadly cells and molecules aimed at clearing a pathogen out of the body. The point of infection can look like the scene of a multi-car crash. The actors in the immune system rush to assess the problem, attack it, clean the area and rebuild new tissue.
To you, inflammation can feel like a stuffy nose, sore throat, tummy ache, fever, fatigue or headache. Yes, the symptoms of an immune response feel lousy, but you must suffer a little to keep the rest of your body healthy over the long term. And for your health and daily well-being, the key is to keep your immune system from underperforming or getting out of hand.
It’s about balance
The immune system, often seen as a ruthless defender, seeks a steady state, not a police state. I liken the immune system to a fiercely delicate combination of a bouncer and a ballet dancer. In fact, many molecules in this complex system are designed to send a signal that it should withdraw, pause an attack and stand down. Without these molecules, the state of inflammation that helps destroy threats would lay your body to waste.
“You need inflammation to protect against invaders. You need policemen,” said Dr. Charles Dinarello, who discovered the molecule that causes fever. (Who better to ask when to take Tylenol? More on that in a moment.) “But if police are too rambunctious they can cause damage to innocent people.”
On a day-to-day basis, honoring the finely honed balance of the immune system is essential to feeling healthy and living well. Instead of boosting your immune system, you should be supporting it. And you should try to never undermine its delicate structures.
Let me illustrate with a personal story of stupidity.
A personal tale of woe
As I wrote this, I was sick with a nasty head cold. It was my own fault. It didn’t have to be this way.
It was the annual early-spring cold. I felt a scratch at the back of my throat. I stepped onto an airplane, bound for my native Colorado and a ski vacation with my family. I skied one day, a second, then a third. Each day I felt so-so, each night worse, until the fourth day, when I could not move. My body put its foot down. I woke up, had a triple espresso and, despite the caffeine, was so exhausted I went right back to sleep. I got a day of blessed rest my body had begged from me. I’d wised up, right? Hang tight, I’m only now getting to the stupid part.
The next day was our very last day of vacation, and I woke up feeling meh. “You should rest,” said my wife, who is a doctor, so she knows. But I didn’t want to miss skiing with our kids, and the idea of being with the family energized me. I strapped on my skis. I took it easy, only occasionally attacking moguls with gusto. I felt great. Had I outrun the virus with my skis?
No, what I had actually done is fooled myself. I’d fired up my adrenaline system, giving myself a short-term boost of energy and the illusion of health, but at the expense of undermining my immune system, ultimately making me much sicker.
This is basic science that comes from our relationship to the lion.
The Immune System and the Beast
Let’s take a moment to understand how (and why) our immune system acts in the face of a threat.
Our immune system took shape roughly 480 million years ago. All jawed vertebrates going back to the shark share its key properties. One property is priority setting. Our defenses must calculate which threat to our survival requires the most attention at any given moment. Which requires the most resources: Infection, tissue repair or the sudden appearance of a lion or bear?
When we face an acute threat, like a lion attack, the body’s network focuses wholly on that threat. Your body goes into an emergency state you may know colloquially as “fight or flight.”
During these periods, the body fires off powerful chemicals, including:
• Epinephrine, which creates a kind of high for the body to subvert fatigue.
• Norepinephrine, which also helps to subvert fatigue.
• Cortisol, which helps the body maintain essential functions, like blood flow.
When these hormones are at work, we can feel generally O.K., as I did while I was skiing. But not only was I still sick, I was also making things worse. That’s because the release of these fight-or-flight hormones dampens our immune response. I was causing my immune system to withdraw.
Why the immune system withdraws
During times of real, acute stress — like threat of being eaten by a lion — our bodies can ill afford to waste resources dealing with illness. Viruses and bacteria, while dangerous, pale in comparison to the gigantic beast with razor-sharp teeth chasing us across the savannah. In that moment, our body needs all our energy, non-essential functions be damned. Step one: survive lion. Step two: deal with head cold.
That is the underpinning of a biological dynamic that, in modern society, we often misinterpret or even foster to our detriment. In real life, we rarely face lions, bears or other mortal threats. The trouble is, our body still gets triggered in the same way in the face of modern threats: a marital challenge, trouble with our boss, the inability to get a son off Fortnite, putting on a pair of skis and facing down a mountain — these threats to your well-being are real, but not quite on the same level as a hungry lion.
“What happens today is many people are living with imaginary bears every step of their lives — something in the news or around the bend is going to get them,” Dr. William Malarkey, professor emeritus at Ohio State University, told me for my book, “An Elegant Defense: The Extraordinary New Science of the Immune System.”
• The high you get from your adrenaline system is not the same as feeling O.K.
There is no lion, so don’t go creating one, and don’t turn a molehill into a ski mountain.
I had a choice about whether to ski and I shouldn’t have, but what about when life suddenly presents you with stress or physical demands? How can you support your immune system then?
Sleep Is a Magic Bullet
Both you and your immune system need rest.
One of the world’s least valuable clichés is that you can sleep when you die. Much truer is: If you don’t sleep, you will die — sooner. Studies show that lack of sleep leads to premature death through diseases like cancer and heart disease, and the reasons have everything to do with the immune system, notes the Mayo Clinic.
When you don’t sleep, your adrenal hormones don’t shut off, which leads to some dampening of immunity, much like when you’re in fight-or-flight. And research shows that lack of sleep leads to a decrease in first-line immune-system cells known as Natural Killer Cells. If you don’t sleep, you are more susceptible to bacteria and viruses.
But research also shows a rise in “pro-inflammatory” signaling when you don’t sleep enough. What follows can be depression, more stress and a cascade of clashing signals.
“It’s a badge of honor to see how little sleep you can get by on,” said Dr. Michael Irwin, professor of psychiatry and biobehavioral sciences at the David Geffen School of Medicine at U.C.L.A for my book, “An Elegant Defense.” “That crazy logic has led to a sleep-deprived society, and that is having huge health consequences.”
A broad study, published in 2009, that summarized findings from more than a dozen research projects included evidence that people need, on average, around seven hours of sleep each night. Moving even below an average of seven hours poses a risk for a range of conditions associated with premature death. Curiously, research shows that excessive sleep can pose a problem too, however experts are divided on the meaning of this research. That is because it is not clear whether people who report sleeping more are actually asleep for, say 10 hours, or whether they are merely lying in bed for long periods, which could be a sign of a different condition, like depression.
In any case, lack of sleep almost immediately tips your immune system into imbalance, simultaneously dampening parts of it and empowering others.
Sleep keeps your system in balance
This might sound contradictory. How can sleep can weaken the immune system, but also lead to inflammation?
Your immune system does not work as a binary system. It is not either on or off. It is made up of many molecules that send different signals, some urging inflammation and others restraining it. Your goal is to create an environment that doesn’t require your immune system to lose its natural balance.
Sleeplessness tips your immune system out of balance, hinders homeostasis, and turns the once elegant system into reckless pinballs of powerful molecules bouncing off your body’s bumper rails, and sometimes through them.
More concretely, it is a hard pill to swallow knowing there is no pill to swallow. The most important steps to support your immune system require discipline and habit.
Exercise, Food and Meditation
Ward off illness with these three staples of a healthy body.
The first few days that I skied while feeling a scratchy throat, my actions were somewhat, mildly, defensible. I told myself what I know to be true: Exercise supports the immune system in crucial ways:
• Exercise that relieves stress helps modulate the adrenaline cycle that can be so detrimental to health.
• Aging people who exercise regularly develop more T-cells (key immune cells) than their sedentary contemporaries.
• Exercise is crucial to avoiding obesity, and obese people experience increased inflammation.
The problem is, exercise helps keep your immune system in balance on a day-to-day basis. But once you get sick, that same exercise can steer resources away from your immune system, effectively tipping the scales in favor of the virus.
Instead of hitting the slopes, I could have helped even the keel of my immune system with meditation and some healthy food.
Mindfulness meditation — the nonjudgmental, in-the-moment awareness and acceptance of our thoughts and feelings — has a calming effect, which in turn can diminish the illusion that you are being chased by a lion or bear. This simple discipline can reduce inflammation, and support your immunity. “Mindfulness meditation may downregulate the activity of major stress axes in the body,” according to an overview of major research about the impact of breathing and other mindfulness techniques on the immune system, published in 2016 in the Annals of the New York Academy of Sciences.
The overview cites multiple studies that offer specific ways that mindfulness appears to support a balanced immune system, including restraining inflammation. But it cautions that these findings are preliminary: “If robust and maintained over time, these types of shifts in immune system activity could potentially have beneficial effects on health by influencing mechanisms that are known to affect biological aging and disease.”
Along with all the other benefits of mindfulness, the prospect of supporting immune health comes here with little risk.
Another way to help your body maintain homeostasis is to eat natural food rather than processed food. For one thing, heavy consumption of processed foods leads to obesity. Natural foods, by contrast, present the immune system with familiar nutrients that we have evolved to benefit from and recognize.
As such, the immune system may be less likely to react, or overreact, to these natural nutrients as alien or foreign and mount a defense against them.
Not only are natural foods beneficial, so is nature itself. Here, I include dirt.
Spend Time With Dirt
Exposure to a great variety of germs can help us stay healthy.
The immune system evolved in a time of great peril. Over epochs, we lived in squalor, with abundant disease and without modern tools to sanitize our food, water and homes.
Today, we have all kinds of tools to clean our environments — antibacterial soaps and disinfectants, and a hypochondriac’s obsession with wiping down every surface. But research shows that when we cleanse our entire world, we deprived our immune system of its natural need to learn and spar. And with all our hygiene, we not only cleanse pathogens but also lots of non-threatening microbes that help train the immune system without any harm to us.
The result? A sharp rise in food and skin allergies in industrialized countries. Allergies are basically the immune system creating inflammation in a body in response to something that doesn’t really cause much of a threat. This happens, the science suggests, because people grow up in such sanitized environments that immune systems don’t calibrate properly to the natural world.
It’s okay to eat dirt, said Dr. Meg Lemon, a Denver doctor who treats people with allergies and autoimmune disorders.
She was only half-kidding. A few encounters with viruses and bacteria today might forestall an allergy tomorrow. What won’t kill you — and most of the world won’t kill you — will bring balance to your immune system.
Frequently Asked Questions
Wisdom has been passed down through the ages – don’t pick your nose; you can eat food on the floor if it’s been there for less than three seconds; eat vitamin C — so what gives with these homilies?
Does vitamin C do anything to help keep me healthy?
The false idea that Vitamin C is a cold cure-all emerged in the 1960s. To repeat: there is no magic pill to keep you forever healthy. The main thing you can do for yourself is to consume natural nutrients when you are sick, and fluids — to replenish what is lost through dehydration owing to fever or to purging of fluids through, well, y’know. Don’t expect a single vitamin or herb to do the trick. One fascinating study done in mice suggests that creatures (mice, humans, etc) that have viruses do better when they keep up the nutrients; in other words, it may not feel great to eat, but it might help your immune system to get the resources it needs. (The study shows that it may be less beneficial, even harmful, to eat when you have a bacterium).
Does being in the cold increase my likelihood of getting sick?
People get sick in winter in part because they’re cramped inside together, and germs get passed more easily in tight confines. Try a nice brisk walk to keep you well.
Should my child eat dirt?
Yes, at least metaphorically speaking. See above.
Should I pick my nose?
Definitely not if other drivers can see you. I kid! Actually, it could help to introduce dirt and other safe pathogens to your body, helping to educate your immune system. Your immune system learns from nature. It needs inputs.
What about vaccines? If I keep my immune system healthy, why do I still need vaccines?
Vaccines are a proven, effective and generally very safe way of helping the immune system do its job when faced with brutal pathogens. Plus, they help keep these pathogens out of the general population, protecting those with less-hearty immune systems from getting deathly sick.
When is a fever considered a risk?
Your natural temperature can fluctuate. For newborns, fevers over 100 degrees are considered reason to check in with a doctor. For children, the number can be as high as 102 before considering treatment. But there is the discomfort associated with fever to consider as well. Which brings us to:
Should I try to reduce a fever?
This turns out to be a question that divides very smart people. Dr. Dinarello, the discoverer of the fever molecule, takes the position that the immune system can get its job done even if you take medicine to reduce fever. “Take the Tylenol,” he said. “I tell parents, ‘You think this fever is going to help your kid get better faster, but I don’t think it is.’”
The highly-regarded Mayo Clinic, by contrast, urges restraint with fever reducers, encouraging people to wait until the fever rises above 100.4 before treating it. A columnist wrote in depth about this debate for The New York Times, ultimately siding with Dr. Dinarello. So, as you can see, reasonable and wise people differ.
What would I do?
During my ski virus, I indulged myself with Advil. In the end, though, that was immaterial. The real problem was that I actively undermined my immune system. The sentence was a virus that lasted a week longer than it might have otherwise — one that confined me to bed, where I belonged in the first place.
Ultimately, the best things you can do for yourself when you’re sick are rest, eat well, don’t turn little things into lions, and remember that your immune system, if given your support, will likely do a darn good job of keeping you at harmony with the world.
Bron: NYT / mei 2019