Zinc: The Gatekeeper of Immune Function
Here’s what you need to know…
Zinc is the “gatekeeper of immune function.”
It regulates communication between innate and adaptive immune cells.
Zinc deficiency has been linked to low immunity, slow wound healing, poor sleep, mental and growth retardation, hypogonadism and acute diarrhea, among other issues.
Athletes require far higher dietary zinc intake than normal populations.
Oral zinc supplements work remarkably well.
While optimizing immunity, zinc also enhances all aspects of sleep quantity and quality.
The Gatekeeper of Immunity
In this day of quarantines and coronaviruses, it’s more important than ever to understand how to maximize your natural immunity. In fact, everyone seems understandably obsessed with boosting their immunity to Wolverine-like levels right now. That’s why Google Trends shows nearly 4x growth in search volume for “immunity” over the past two weeks, and 3x growth for “zinc”.
Wait…what does zinc have to do with immunity?
That’s a very good question. And the answer is: everything.
Zinc is known as the “gatekeeper of immune function,” and for very good reason. As a trace metal, it’s an essential cofactor for over 300 enzymes and 1,000 transcription factors in the body. Moderate zinc deficiency is ludicrously common in humans, and the condition has been found responsible for a whole host of nasty problems: growth retardation, hypogonadism (i.e. your balls don’t work), inefficient wound healing, low immunity (your body can’t fight off disease), and mental retardation.
In fact, zinc’s potent effects as a dietary supplement have been “settled science” for some time. That’s a major reason why Hibernate includes a hefty 50mg of the highest quality zinc orotate - sleep, immunity, hormone levels and recovery all go hand in hand.
But before we dive in to the science behind the “gatekeeper of immune function,” let’s first determine what this vague term “immunity” actually means.
What is Immunity?
“The ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells.”
Immunity, basically, is our bodies’ defense system against all the invisible bugs and toxins in the world. Yet it’s not at all simple. It’s not a single-variable system, not something we can track with a single gauge like blood pressure or resting heart rate. In fact, it’s a combination of basically all the “healthy” variables we can track.
Wikipedia describes immunity as:
“…the balanced state of multicellular organisms having adequate biological defenses to fight infection, disease, or other unwanted biological invasion, while having adequate tolerance to avoid allergy, and autoimmune diseases.”
Note that first term: “balanced state.” This is the key to understanding your immunity. When all of your biological systems are operating at 100%, that’s peak immunity. That means your body is capable of fighting off disease to the best of its abilities. Thus, in a reductive sense, immunity is health.
Okay, great. Having high immunity means being healthy and capable of living through flus, allergies, colds, cancers, and everything else Mother Nature throws at us.
But where does zinc come into play?
Zinc and Immune Function
If there’s a single element or nutrient in the body that seems most closely aligned with immunity, its zinc. Yes, Vitamin C plays a major part. Then of course there’s Vitamin D (a healthy dose of which is also available in Hibernate), which is especially useful when fighting off respiratory infections. Remember - immunity is a complex system which integrates all the qualities we think of as “health.” Everything works together.
But for some reason, zinc seems to work a little harder, and researchers have known this for half a century. Largely due to our crappy diet full of empty grains, zinc deficiency has been observed in giant swaths of the human population, and linked to everything from sickle cell disease to acute diarrhea.
Yes, if there’s a sign that your immune system is out of wack, acute diarrhea is it.
Zinc, however, is not the ammunition that our immune system fires at nasty flu invaders. Instead, it seems to function more like a communication system. When zinc levels are balanced (zinc homeostasis), intracellular signaling between both innate and adaptive immune cells seems to operate at its peak.
Zinc, thus, controls the intracellular Internet which allows the immune system to talk and redirect white blood cell soldiers toward foreign invaders in the body.
When zinc levels are low (zinc deficiency), the immune system can’t communicate, and your body functions about as well as ancient Rome did with those hairy barbarians at the gate.
But don’t take our word for it:
Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases.
After the discovery of zinc deficiency in the 1960s, it soon became clear that zinc is essential for the function of the immune system. Zinc ions are involved in regulating intracellular signaling pathways in innate and adaptive immune cells.
-- Zinc as a Gatekeeper of Immune Function. Wessels I, Maywald M, Rink L. Nutrients. 2017 Nov 25;9(12). pii: E1286.
Zinc deficiency affects immune cells, resulting in altered host defense, increased risk of inflammation, and even death. The micronutrient zinc is important for maintenance and development of immune cells of both the innate and adaptive immune system. A disrupted zinc homeostasis affects these cells, leading to impaired formation, activation, and maturation of lymphocytes, disturbed intercellular communication via cytokines, and weakened innate host defense via phagocytosis and oxidative burst.
-- Zinc and immunity: An essential interrelation. Maares M, Haase H. Arch Biochem Biophys. 2016 Dec 1;611:58-65.
How Zinc Deficiency Affects Athletes
As discussed in our previous post on magnesium, hard-training athletes have different nutritional requirements than the rest of the population. (Big surprise, huh?) Some estimates indicate that weight-lifters, track runners, swimmers and kettlebellers need up to 20% more than the standard Recommended Dietary Allowance of key minerals.
Zinc is no exception.
In a 2018 meta-analysis of 12 different studies, Australian researchers found that athletes consistently show lower levels of serum zinc concentration, despite higher dietary zinc intake. In other words, the average athlete consumes more zinc than normal people, but it’s still not enough to reach the balanced state of zinc homeostasis desirable for peak immune function. Perhaps this partially explains why top-level athletes are more likely than normal populations to get upper-respiratory tract and skin infections?
Okay, so training depletes zinc and lowers our immunity. Fair shake. We like training hard, and we suffer for it. But is a zinc supplement all we need to maintain peak immune function?
Well, in some cases it’s just the ticket.
Way back in the 1980s, military researchers found evidence that zinc, when administered as an oral supplement, has a powerful antioxidant effect after intense bouts of exercise.
In 2004, Turkish scientists gave zinc supplements to high-school and college-age wrestlers, and found that a hefty dose of 3mg/kg of bodyweight drastically increased erythrocyte, leukocyte, and thrombocyte counts. (In case you skipped biology class, these are the red/white blood cells and platelets responsible for carrying oxygen, fighting infection, and healing wounds.)
In 2010, the same intrepid Turks repeated the study on a new set of wrestlers and compared them to sedentary individuals. In the end they found zinc supplementation led to significantly higher blood-serum levels of three powerful antioxidants: glutathione, glutathione peroxidase, and superoxide dismutase. This indicates that zinc may help maintain the balance of free radicals and antioxidants our immune systems need to fight infections.
So, even as athletes require higher amounts of zinc to ward off immune dysfunction, oral zinc supplementation seems to be a perfectly fine means of filling your dietary gaps.
Zinc Regulates Sleep
By this point, it should be fairly intuitive that good sleep is necessary for peak immune function - especially the deep, slow-wave sleep most affected by zinc deficiencies.
It should also come as no surprise that zinc plays a role in governing healthy sleep. This is the reason we included it in the Hibernate formula in the first place. Yet the exact role zinc plays is still up for debate.
Researchers have long known that zinc serum levels are closely tied to Central Nervous System activity. It seems to regulate essential mechanisms for neurotransmission and the storage of spatial memories in learning tasks. When administered as a supplement, it also appears to shorten the time it takes to fall asleep (sleep latency), increase the overall amount of sleep, and improve sleep quality in both rats and humans.
Japanese researchers studied this phenomenon in 2017. Though the underlying mechanisms have yet to be defined, their conclusions were firm:
In our experiments, we found that zinc concentration increased in the serum up to 10-fold after the oral administration as compared to baseline. We therefore hypothesize that orally administered zinc reaches some specific compartment of the CNS after rapidly increasing in the blood, thus activating a signaling pathway that is responsible for the promotion of sleep.
Why were they even studying the link between zinc and sleep in the first place?
Because in the last decade, multiple studies in China and Korea have analyzed thousands of adults and children and consistently found that the participants who slept the most (up to 9 hours a night) had the highest concentrations of zinc in their blood.
So, we may not fully understand HOW zinc regulates our sleep, but the evidence is clear that it affects it in a very real way.
And if you want super-immunity, then trust us, you need to optimize your sleep. Especially considering the evidence that poor sleep lowers the effectiveness of flu vaccines.
The science is clear: if you want peak immunity, then you need to ensure zinc homeostasis. Zinc is partially responsible for communication between immune cells, and if you’re suffering from zinc deficiency, a whole mess of nasty health problems can rear their ugly heads. Luckily, oral supplements do a fine job of maintaining your zinc levels, and they also give you the added benefit of longer, higher-quality sleep.
Today more than ever, it’s vital to ensure that your body is equipped with all the minerals and nutrients it needs to sleep hard, recover, and fight off disease and infection.
Pay attention to zinc. It’s the “gatekeeper of immune function” for a reason.