Zinc's Essential Role In Human Health & Evolution (+Huge Benefits)
That's boring...
"Zinc?"
Yes, zinc...
Zinc is another mineral, just like magnesium. I've written an extensive blog post on magnesium before.
"Why should I worry about that complicated stuff, such as a mineral as zinc?"
Great question...
I'll tell you why:
Zinc is pretty easy to understand. And if you're taking in too little zinc, the deficiency is easy to fix.
Yes, really.
Fixing that mistake deficiency can have huge benefits for your health (I'll tell you why soon.)
Having mineral deficiencies is like having a problem with the software in your computer.
If you don't know how to fix that software problem, you'll spend hours upon hours fixing stuff.
And yet, an expert can simply tell give you a quick fix, even over the phone.
I'm like that for zinc - a "technician" who can give you easy-to-follow steps. Why? Well, treating (possible) mineral problems are the same as software problems.
You just need to know the right steps - then execute.
So I'll tell you exactly what you need to know about zinc, and how to fix possible problems.
You might think: "why should I care about zinc in the first place?"
Because zinc is definitely not boring:
In fact, zinc is highly exciting. To get you worked up, let's first consider some of zinc's benefits:
Zinc increases your overall energy levels, helps you sleep deeper, strengthens your immune system, boosts your gym performance, and improves your well-being and thinking-ability (such as memory).
That's just a shortlist of zinc's benefits...
Ready to sign up?
There's more though:
Zinc helps you prevent many diseases such as diabetes, Alzheimer's, and several autoimmune diseases.
And from an evolutionary perspective, additionally, zinc really plays a major role in what made you and me typically human.
While that statement sounds "mystical", it really is not...
Our ancestors - which were not Homo sapiens (yet) - started consuming animal foods that contain great quantities of highly absorbable minerals more than two million years ago.
Yes, that's two million years, not two thousand.
These minerals, combined with high-quality fatty acids, have been essential to our ancestors' brain development. The presence of brain-stimulating nutrients has allowed for the eventual development of human beings - Homo sapiens - from our primate ancestors such as chimpanzees and gorillas.
Over the course of millions of years, our ancestor's brains grew bigger and bigger, reaching a peak around 30,000 years ago. Somewhere in the last 15,000 years, humans went the wrong way though: we started relying on plant foods excessively, at the exclusion of animal foods.
(I'm not saying plant foods are unhealthy, not at all, it's just that an overreliance is not optimal for many!)
Relying highly on plant foods creates problems because the foods that have the best absorption of zinc are animal foods such as oysters, red meat, lobster, and crab.
Plant foods - while containing lots of zinc in absolute terms - need to be specifically treated in order to be properly utilized by the human body. Example? Grains need to be soaked and cooked for you to be able to get a proper zinc-value out of these foods.
But even with good treatment or processing, plant foods are still inferior for getting adequate zinc levels - plant zinc absorption levels cannot touch those of animal foods.
(If you're interested in the topics of vegetarianism and veganism, read THIS treatment by Alex of this topic.)
So what's the solution?
Eat more foods that contain highly absorbable zinc.
You might say "I don't want to..."
In that case, there's one solution:
People who are unwilling to consume lots of zinc through animal foods - and mostly rely on plants for their zinc intake instead - are highly recommended to test their zinc status through a lab test as well as considering zinc supplementation. I'll talk more about that subject in the next installment of this blog post.
Here's the layout of this 3-part series:
- The first blog post covers the basics around zinc as well as its evolutionary importance in human health. Zinc benefits are also considered.
- The second installment considers the best foods for getting adequate zinc and the best foods to prevent deficiencies forever.
- The third and last installment considers deficiency signs as well as lab testing to ensure you've got adequate status.
So, contrary to my earlier assessment that zinc may be "boring", nothing could thus be farther from the truth. Zinc is not a side-issue.
Let me tell you why:
Two billion people on this planet have sub-optimal zinc levels. Yes, that's billion with a "b" - equaling more than 25% of the people on this planet...
Consequence?
Tens of billions of IQ points are lost on a worldwide scale due to zinc deficiencies - which are inexpensively curable.
Zinc deficiencies, moreover, literally kill people as well. To be more specific, almost 200,000 children die on a yearly basis due to diarrhea that's directly preventable by getting adequate zinc in their bodies.
Horrible but true...
How do you know whether you're low on zinc?
Signs of a zinc deficiency are being sick often, having a poor immune system, feeling down and depressed, anxiety, having poor memory and focus, recovering poorly from stress, poor skin, and low sleep-quality.
Simply put: you're missing out in life by not getting your zinc levels handled.
Want to know more?
Read this entire blog post series (in several sessions if you have to).
Want a simple infographic that describes the 10 most important lessons I got from reading hundreds of studies on zinc? Subscribe below:
Zinc's Essential Role In Human Health & Evolution (+Huge Benefits)
Here's the layout of the upcoming 3-part series on zinc status:
Table Of Contents:
Zinc Basics (1st Installment Of Series, which you're reading right now)
Understanding Zinc Through Understanding Our (Human) Past
Zinc's Overall Health Benefits--And Diseases Affected By Zinc
Section finishing Thoughts: Many People Misunderstand Zinc's Role Because They Don't Understand Evolution
Optimizing Zinc Intake (2nd and 3rd installment of this series)
The Best Zinc Foods And Your Daily Zinc Needs
Zinc Deficiency Signs And Prevention
Supplementing With Zinc?
Measuring Your Zinc Levels - Lab Tests
Finishing Touch (2nd and 3rd installment of this series)
Conclusion: Zinc Is Not Just An Afterthought.
Understanding Zinc Through Understanding Our (Human) Past.
Why talk about zinc's influence on your health in the first place?
To correctly understand the role of zinc in your health I need to take a detour. So let me tell you a story - a narrative of our human past. If you've been reading some of my previous blogs, you've probably read several times that humans evolved in Africa roughly 200,000 years ago.
We've gone through lots of hardship and difficult periods since that time. Between 195,000 and 130,000 years ago, for example, we lived through a mini-ice age in Africa.[1; 2] During that time, Africa was a lot dryer and cooler than it is today.[3; 4]
(The exact timing of these events varies)
Another ice age existed between 115,000 and 11,000 years ago. We only had a few small periods in which most of the continents on our planet were very warm. Large parts of Northern Europe, North America, and the Northern parts of Asia were subsumed under ice.
Fortunately, human beings had a companion during these hundreds of thousands of years. That companion was (and is) shellfish.[5; 6 ;7; 8]
Shellfish have the advantage of being able to survive in much cooler temperatures.[9] In fact, the quintessential shellfish, the oyster, often grow better in cooler temperatures.
The human brain and shellfish are a perfect match: tools assist human in their "hunt" for these premium foods.[10; 11; 12; 13; 14] It turns out that shellfish are extremely high in brain-stimulating nutrients, such as iodine, selenium, iron, copper, and you guessed it: zinc.[463]
In fact, shellfish are so nutritionally precious that humans even have become territorial because of the exploitation of marine food sources. Shellfish rich territories became heavily defended by tribes of human beings who settled there.[12]
Of course, humans relied on other foodstuffs as well, such as meat, tubers, and eggs. My point is, however, that there's a shift towards more animal foods compared to our primate ancestors.
Humans are not the first species that has relied more on animal foods though.
Why?
Let's take an even wider perspective...
For millions of years, shellfish has already been a companion for the different predecessors of the human species: hominins.[443; 444; 455; 456; 457; 458; 459; 460; 461; 462; 463]
To be more precise: already since 2.6 million years ago, our ancestors began eating more meat.[464] As a result, our brains began growing.
Unlike our primate ancestors, such as chimpanzees and gorillas, our human hominin predecessors started relying less and less on plant food.
As you probably know, our primate ancestors such as gorillas thrive in rainforest-like areas where there's plenty of vegetation. Gorillas and chimps don't rely on meat consumption all that much. Only 3-5% percents of their diet consist of meat, such as ants.
The two most important examples of species that preceded us are the Homo erectus and Homo habilis. Human beings evolved out of these two species (with intermediary steps that I'm not going into right now).
The Homo habilis lived about 2.1 million and 1.8 million years ago - and is specifically known for its tool use. The Homo habilis uses stone tools to butcher and skin animals, for example. That Homo habilis had a brain size of roughly 700 to 800 cubic centimeters (cm3) and weighed about 50 kilograms.
The brain of the Homo habilis makes up 1,5% of its lean body mass, which is much greater than its previous ancestors (such as chimpanzees or gorillas)
(Sadly enough, the Homo habilis is now extinct.)
You can view the Homo habilis below:[466]
Next, there's the Homo erectus who lived between 1.8 million and 200,000 years ago. The words "Homo erectus" can be translated as "upright standing human". The homo erectus thus existed simultaneously with human beings for a while.
Observe the Homo erectus below:[467]
I hope you can see that through the development of the Homo habilis and Homo erectus, our predecessors slowly became more human-like.
In fact, the secondly displayed Homo erectus has a brain size to lean body mass ratio of 1,6 - 1,7%. Human beings (Homo Sapiens), finally, have a brain size to lean body mass ratio that's much higher, approximating or exceeding 2%.
I'm using a lean body mass ratio calculation because human beings - as Homo sapiens - started accumulating more and more body fat, even as a fetus.
As humans, our brain size to our bodyweight ratio is thus much smaller than our brain size to lean body mass ratio.
Specializing in brain-development has thus placed human beings at the top of the food chain - as apex predator.
So what's my point?
In summary, our very early human predecessors started incorporating more animal food into our diet - millions of years ago - with easily absorbable minerals.
That food did not only include shellfish, game, but also turtles, alligators, and (non-oily) fish, which are all good zinc (and other mineral) sources. Even extremely large herbivores were hunted, such as elephants and mammoths.
As an interesting fact, the practice of meat and shellfish consumption is already observed in our hominin predecessors 2 - 1.5 million years ago.[456; 464; 468; 469] Of course, remember that eggs and meat are two other common ancestral zinc sources.
Zinc is one of the minerals that could be consumed much more efficiently by our transition from a mostly herbivore to an omnivore diet.
African lakes such as these are one
key to understanding our human past. These lakes
are rich in shellfish and mineral-rich vegetables.
Why does that human location matter? Well, zinc is a trace mineral that is not stored in the human body in any great quantity. There are also indications that just consuming vegetation cannot explain why hominin brains developed the way they did.
You thus need to consume this mineral on a steady basis to avoid a deficiency. For that reason, I'm going to supply you with a full review of zinc's health benefits in the next section.
Oh yeah, one important disclaimer:
There are probably strategies that are more important to your health than trying to optimize yours zinc intake. Making sure you're getting enough sunlight, optimizing your sleep quality, and avoiding artificial light at night come to mind.
With this blog, it's not just my intention to give you lots of highly-useful information, but also to tell you what's important and what health strategies to prioritize.
Simple...
Zinc's Overall Health Benefits & Diseases Affected By Zinc.
The list of zinc benefits is huge.
It's therefore not surprising that zinc deficiency - a topic we'll come back to in a next section - has such a huge influence on your health. But first I'll give you a list of all the zinc benefits in existence.
Ready?
Let's go...
- Zinc improves the amount of deep sleep you get[38; 39; 40; 52; 53; 54; 55; 56; 58; 59; 60]
Yes...
That's right.
Increasing deep sleep zinc enhances the overall quality of your sleep. Why? Deep sleep is one of the most restorative parts of your sleep (together with the periods in which you dream). Deep sleep is necessary for physical healing and the formation of memories and many other things.
How does zinc affect deep sleep?
The zinc you ingest can directly pass into your brain.
Having good zinc levels are also associated with having a proper sleep length - which consists of 7-9 hours of sleep for most individuals. Of course, there are "freaks of nature" who can get away with much less sleep...
When supplemental zinc is given to people who have a deficiency you'll sleep up to an hour longer each day. In addition to improving overall sleep quality, the time it takes to fall asleep is also decreased when you have an optimal zinc intake.
There are indications that taking zinc from foods slightly better results for improving sleep quality than supplements.[57]
I'm very wary of "health experts" who oversimplify sleep issues by thinking that just magnesium or just wearing blue-blockers will solve clients' every problem. The truth is that sleep issues can originate from many different causes.
Again, sleep is not an afterthought (even though many people in modern society treat it as such):
Not getting enough high-quality sleep puts you at risk for getting diabetes, cancer, and heart disease (at least, in the long run). Poor sleep also increases your chances of overeating, lowers (cognitive) performance, and makes you slightly depressed.
You thus need to prioritize sleep. Yes, the need to prioritize sleep is an objective fact. Read Alex's blog post on deep sleep to learn more about prioritizing sleep. - Zinc increases your energy levels[96; 102; 103; 104; 105; 106; 107; 108; 305; 306; 372]
How?
First of all, zinc will increase the levels of several thyroid hormones in your body. The thyroid gland is located at the front of your neck and is essential for keeping your body's overall energy production high.
Once you're low on zinc you're more prone to have lower energy levels. Having low zinc levels can literally cause thyroid problems such as "hypothyroidism". Hypothyroidism is more commonly known as an "underactive thyroid".
If you currently have thyroid problems, zinc can help reverse that condition. How? Zinc helps convert the inactive thyroid hormone T4 into the active T3 hormone.
Don't try to remember these hormones names though--you only need to know that your body's cells can use that T3 hormone better.
Another mechanism by which zinc can increase energy production is removing a compound called "nitric oxide" from your mitochondria.[304] Mitochondria are the energy-producing factories of your cells.
Nitric oxide prevents your mitochondria working at full capacity - and zinc thus helps solve that problem.
But there's more:
In children, having adequate zinc will stimulate growth.[27; 28] Without sufficient zinc, children's bodily growth will be stunted. Stunted growth is especially dangerous as the problem can be irreversible.
Zinc will also help children who are underweight increase their body mass. Zinc does not only have benefits for the body mass of children though:
Zinc stimulates appetite.
People who have adequate zinc levels are much more prone to increase their overall nutrient intake. How? With a zinc deficiency, you're more likely to under-eat because your appetite is lower - risking becoming underweight.
The problems of zinc deficiency are especially visible if you've got anorexia. Anorexic people are more prone to have a zinc deficiency - leading to a vicious cycle of under-eating because zinc deficiency suppresses your appetite.
Of course, under-eating leads to low energy in the long-run.
Next, zinc can lower excessive amounts of unhealthy fatty acids in your cells, such as those found in vegetable oils. An excess of these fatty acids is dangerous to your energy production.
Bottom line?
Zinc helps improve your overall energy levels by making your thyroid organ healthier, improving your thyroid hormones, stimulating appetite, and making your cells healthier.
That's a big win...
Next: - Zinc keeps your nervous system healthy.[193; 194; 470; 471]
Zinc helps the cells in your nervous system communicate, and helps new nervous system cells grow.
It's therefore not surprising that zinc deficiency problems have been linked to health conditions such as Alzheimer's disease, an impaired brain development, and mood disorders.
Having low zinc levels in your body may also make you more susceptible to autoimmune disease.
The effect of zinc on your nervous system should not come as a surprise, given that I've talked about the essential role of nutrients such as zinc for developing bigger and more efficient brains in our ancestors... - Zinc acts as an antioxidant in your body.[75; 195; 196; 472]
To understand the term "antioxidant", let's first take a quick detour:
As a byproduct of energy generation in your body, what are called "reactive oxygen species" are created. These reactive oxygen species can damage cells, quicken aging, and put you at risk for getting many modern diseases.
Zinc can counter excessive "reactive oxygen species" as an antioxidant - inhibiting the (possible) negative effects of "reactive oxygen species".
Additionally, zinc boosts the levels of the most important antioxidant in your body, called "glutathione". People who have low zinc levels have less glutathione available in their bodies.
Glutathione is absolutely essential import to your overall health.
Why?
Let me give an example:
With sufficient glutathione, you're better able to get rid of heavy metal toxins in your body. Heavy metals such as lead or mercury can be found in paint, tooth fillings, makeup, among others. You can also get exposed to heavy metals through the off-gassing of industrial processes.
The bottom line is that that glutathione helps detox processes in your body, and protects against aging.
Simple... - Zinc increases reproductive health and fertility.[92; 169; 170; 171; 172; 173; 174; 175; 176; 177; 178; 179; 180]
All right, the serious topics.
Hold tight...
Let's first talk about women.
(It should not come as a surprise that I find women more interesting right?)
The more oxidative stress you have - or "free radicals" - the less fertile you become as a woman.
And there's more:
Zinc helps maintain a healthy menstrual cycle and ovulation. If you're zinc deficient, your monthly eggs are of lower quality and the development of the (prospective) children is disrupted.
Zinc is also necessary for proper sexual development, moreover, when you're entering your teenage years as a woman.
Additionally, zinc is important during pregnancy. Having adequate zinc levels in your body, for example, can reduce the occurrence of an early birth of your child. Your child's birth-weight is also increased, and the chances for prolonged labor reduced when you've got sufficient zinc in your body.
Zinc is thus a big win-win during pregnancy.
How about the role of zinc in male fertility?
In studies with male rats, zinc can improve libido. Unfortunately, that effect has not yet been proven in human beings. Many men nevertheless report that zinc improves their libido.
What do human studies tell you about the relationship between zinc and fertility?
Infertile males, in general, have much lower zinc concentrations in their sperm than fertile men. If you supplement with zinc as a man, you'll significantly increase the amount of sperm during an ejaculation, the health of the sperm, and even the movement capacity of the sperm.
Interestingly enough, free radicals are more plentiful if you've got poor sperm. Remember that a previous zinc benefit stipulated that zinc has antioxidant properties. Even in your sperm, zinc works as an antioxidant, preventing free radical damage.
Male fertility has been declining for many decades now. Low zinc levels may thus be one of the reasons men are getting less fertile over time... - Zinc enhances athletic performance.[90; 91; 92; 93; 94; 95; 96; 97; 98; 99; 101; 102; 160; 161; 259; 260; 261]
You might know about athletes using zinc supplements to increase their performance. Athletes have good reasons for that strategy...
Why?
First, there's "testosterone", which many of you know is a hormone. If you're deficient in zinc, your testosterone levels will become lower. While testosterone is present in (much) higher quantities in men than women, both sexes need optimal testosterone levels to feel and perform well.
Increasing your zinc intake can help you deal with a testosterone deficiency, and sometimes even fully resolve the problem (if zinc deficiency is your only problem causing low-testosterone levels.)
There are more athletic zinc benefits though:
Testosterone will improve the amounts of muscle mass that you carry, your overall strength, recovery after workouts, and also your general well-being.
Additionally, zinc stimulates a compound called "IGF-1". Don't worry about that complicated name. IGF-1 stimulates overall growth in your body, which included your muscle cells.
Zinc also reduces your fatigue levels. Lower fatigue helps you recover quicker after workouts. Zinc even helps repair your tissues after exercise.
What's even more astounding?
Intense exercise depletes zinc all by itself. When you exercise a lot you're thus going to need a higher zinc intake compared to individuals who do not exercise heavily.
Can I give more zinc benefits?
Sure...
In men, zinc also boosts a hormone called "DHT". DHT is actually the most male-like hormone in your body. Another benefit is that zinc increases the levels of "growth hormone", which acts as an anti-aging hormone.
Zinc deficiency is thus one of the reasons why people spend lots of time in the gym without getting great results.
Even in elderly people, zinc increases how well they're able to move in their daily life - which is kind of their "athletic performance".
(I hope you're observing by now that zinc is a mineral that's important for your all-around health. Living with a zinc deficiency is like attempting to drive a car while continually pushing your break). - Zinc helps prevent cancer.[198; 199; 200; 201; 202; 203; 204; 205; 206; 207; 314]
How?
Zinc is essential in the creation and functioning of so-called "natural killer cells". Natural killer cells are a specific type of white blood cells that are specialized towards cancer prevention.
Many cancer patients have low zinc levels. While having low zinc levels does not prove that an absence of zinc causes cancer, the relationship is interesting because zinc has been shown to inhibit the creation of cancer cells.
And there's more proof that zinc plays a role in cancer:
The course of different types of cancers (and their prevention) can be affected by zinc our zinc intake. Examples include breast cancer, prostate cancer, and pancreatic cancer.
(If you don't recognize these organs: the prostate is a gland that's located below the bladder in males. The "pancreas" is located in your upper belly and creates the hormone "insulin" that most of you probably know of. Breasts? Even men know where these are located...)
There's more though:
Another mechanism by which zinc inhibiting cancer is by preventing damage from occurring to your DNA. To be more precise: zinc prevents the "reactive oxygen species" that I talked about earlier from damaging that DNA.
Unfortunately, much more research is needed to fully flesh out zinc's role in cancer. Let's consider an area where zinc's effects are well-proven: - Zinc makes your bones stronger.[397; 398; 399; 400; 401]
Yes...
Zinc plays a major role in the prevention of "osteoporosis", a condition where your bones get weaker over time. Osteoporosis is increasingly risky to develop the older you get.
If you have bone problems you're prone to have too little zinc stored in your body as well.
Why?
Remarkably, people with osteoporosis generally have lower intakes of important minerals such as calcium, magnesium, and you guessed it: zinc.
Zinc plays a major role in bone growth - which is one of the reasons children with zinc deficiency get stunted growth.
Of course, I'm not saying that osteoporosis is primarily or exclusively a zinc problem--what I'm saying instead is that having low zinc levels exacerbates bone-formation issues.
Proof?
Zinc is so essential for bone health that supplementing with zinc may even help fractures heal more quickly.
Consume your zinc-rich-foods for strong bones... - Zinc boost your immune system[61; 62; 63; 64; 65; 66; 67; 73; 74; 75; 100; 169]
How?
Firstly, as an example, zinc can help prevent a common cold. The best way to prevent that cold from occurring is by using zinc lozenges. You need quite a high dosage of that lozenge: 75 milligrams to be exact.
Studies show that it's best to consume that lozenge during the first day you have symptoms.
If you get older, zinc can lower your overall propensity to become sick as well. How?
Zinc helps create and build white blood cells - which counter invaders and foreign substances in your body. Zinc additionally increases how well these white blood cells function.
If you don't have sufficient zinc in your body, you'll not be able to properly fight infections, for example.
And there's more:
When you have an immune response, zinc helps increase inflammation levels. In principle, having high inflammation levels are not beneficial to your health. But if you have an immune reaction, you need temporarily higher inflammation levels to help your body defend itself.
In other situations - where an immune response is not warranted - zinc actually decreases your overall inflammation levels.
Why is having low inflammation levels important?
Chronic (excessive) inflammation contributes to many modern diseases, such as cancer, nervous system problems, immune disorders, and aging itself. Zinc may thus slow down the aging process.
Who doesn't want that benefit? - Zinc prevents skin diseases.[129; 130; 131; 132; 133; 134; 135; 136; 137; 138; 139; 140; 313]
Yes, really.
Zinc is one of the most prominent minerals found in the human skin...
Zinc has big effects on acne, for example. I wish I would have known that zinc has this effect when I was younger because I had enormous issues with acne back then (and have acne-scars to prove it).
Zinc is a big potential win for changing commonly used acne treatments.
Why?
Acne problems are currently being treated with gels, antibiotics, skin creams, antibacterial soaps, and washes. If you've got really bad acne, these solutions won't even work.
What's more disturbing is that these "solutions" often have side-effects, such as skin peeling and dryness.
Want to know a crazy fact?
The knowledge that zinc is a possible solution for acne problems has been known since 1977. It's pretty amazing that people are still using all kinds of expensive solutions while zinc may be all they need...
But zinc has many more effects on your skin.
Wound healing might be delayed if you've got low zinc levels. Different wounds may be treatable by applying zinc topically: burning wounds, physical trauma damage, surgery cuts, or wounds because of diabetes side-effects.
That's all?
No:
A skin problem that's more commonly occurring, skin lesions, is curable with zinc. "Psoriasis" - a condition where the immune system attacks your own skin that consequently becomes abnormal - is treatable with a topical zinc skin-cream.
Warts on your skin?
Use zinc.
To treat warts, you can use both a zinc skin-cream or a regular supplement. Lastly, several other skin diseases from developing, although I won't go into deeper detail there.
Overall, there's little downside to trying zinc if you've got skin issues. You can get a high-quality zinc-supplement for $15 - or just buy better food... - Zinc may counter allergies.[385; 386; 387; 388]
If rats are given zinc before getting exposed to an allergen, they're having a less strong immune reaction compared to an absence of zinc.
Children with food allergies also have lower zinc levels in their bodies than children without allergies. When children with asthma - a lung problem - are given a zinc supplement children's overall symptoms become less severe.
Again, zinc may offer an inexpensive solution if you've got allergies. In general, my advice is to try upping your zinc food (or supplement) intake before trying more expensive therapies. - Zinc improves your eye health.[69; 70; 71; 72]
Due to aging, many people over 60 experience vision loss. One common age-related eye disease is called "macular degeneration". In that disease, part of the light-sensitive area in the eye degrades. Fortunately, zinc slows that degeneration process.
Chronically dry eyes, and a condition called "cataracts", can also be helped by having an optimal zinc intake. "Cataracts" denote a clouding of the lens of your eye which makes seeing things more difficult.
How can zinc's have such widespread effects on eye health?
Well, elderly people are often deficient in zinc, which partially explains why they have so many eye problems. Of course, there are other reasons for vision problems as well...
Next, there's a biggie for all of us: - Zinc improves the health of your heart and blood vessels.[76; 77; 78; 79; 80; 82; 83]
Your heart and blood vessel health - also called "cardiovascular health" is, highly influenced by zinc.
People with the highest amount of zinc in comparison to iron, for example, had half the chance of getting cardiovascular disease than people with the lowest zinc status.
People with a condition called "heart failure", moreover - whereby the body is unable to pump sufficient blood for proper cell functioning - have lower zinc levels than people without that disease as well.
Zinc helps prevent an insufficient blood supply from developing in the heart. Through that mechanism, zinc may help prevent a heart attack from occurring in the first place.
Additionally, zinc also improves your cholesterol levels. What is commonly called "bad cholesterol" or your "LDL cholesterol" - although that assessment is somewhat erroneous - is lowered by having an optimal zinc intake. - Zinc keeps your gut healthy.[224; 225; 226; 227; 228; 229; 230]
How?
Zinc can make your intestines less permeable to toxins. If you're deficient in zinc, the number and types of bacteria in your gut may also be altered (for the negative).
Interestingly enough, minerals such as zinc and magnesium are not often emphasized in gut problems.
Most people, when thinking of the healing gut problems, instantly assume that probiotic supplements are the first line of treatment. I would prioritize mineral deficiencies and getting enough sunlight any day. - Zinc helps your liver do a better job.[220; 389; 390]
Having a zinc deficiency is intrinsically tied to developing poorer liver function.
While no high-quality human studies have been carried out, it does seem that having an adequate zinc intake helps deal with liver problems.
If you've got liver cirrhosis, for example - which is scarring of the liver - the buildup of toxins can be reduced. The liver is one organ that's responsible for removing toxins from your body.
Supplementing with zinc can decrease stress on the liver, lower the number of toxins, and keep liver cells overall healthier. Your liver function will also improve when taking in adequate zinc. Scarring of the liver is also reduced with adequate zinc.
Drinking a lot? Don't just increase your B-vitamin intake, but also make sure you get more zinc as well.
Wish I had known that info during my college days... - Zinc helps your body manage blood glucose more competently.[81; 82; 83; 84; 85; 86; 87; 88; 89; 208]
Poor blood glucose management plays an essential role in diseases such as diabetes. The most commonly held theory is that people with diabetes have a problem with transferring glucose (or carbohydrates) from the blood into their cells.
With a sufficient zinc intake, your blood glucose levels are lowered. If you're already at risk for developing diabetes, zinc is a great way to lower your chances of getting that disease.
Zinc influences many mechanisms in relation to diabetes:
The health of the cells of your "pancreas" organ - which stores and creates insulin - is also improved through increasing your zinc intake towards optimal levels. These specific cells (can) lose their function once you get diabetes.
Zinc even helps in the creation of the insulin hormone in the pancreas. And there are more benefits:
If you resolve a zinc deficiency through supplementing with zinc, you'll also lose fat. Managing blood glucose thus not only helps prevent diabetes but also helps you keep a healthy body weight.
Managing blood glucose is not just beneficial if you're diabetic or at risk of becoming diabetic though--everyone benefits. Obese people (non-diabetic) lose weight when optimizing their zinc intake.
Essence? When insulin can do its job better in your body, you're simply more prone to lose fat.
Overall, zinc thus seems very vital to managing blood glucose properly - which is not accidental.
Why?
Zinc has played a quintessential role in the human body - and that of our hominin predecessors - and was consumed in high quantities in the previous millions of years. - Zinc increases the dopamine levels in your brain.[393; 394; 395]
You've heard me talk about dopamine a lot on this blog.
I have argued before, for example, that dopamine plays a major role in maintaining happiness. To be more precise, you need high dopamine levels to feel good, motivated, assertive, and to take action in life.
Zinc - not surprisingly - also plays a role in creating dopamine in your brain.
Although most research is carried out on animals, zinc does seem to make nerve cells associated with dopamine in your brain more excitable. In other words, the threshold to use more dopamine in your brain is lowered.
Zinc also allows dopamine to be used for longer periods of time in the brain.
Interestingly enough, some conditions like Attention Deficit Hyperactivity Disorder (ADHD) are also associated with both a dopamine deficiency as well as a zinc deficiency...
Overall, zinc thus helps your attention and motivation stay high.
Zinc can do more for your mood though: - Having enough zinc simply makes you feel better[109; 110; 111; 112; 113; 114; 115; 116; 117; 118; 119; 120; 121; 122; 123; 182; 183; 184; 250]
Zinc combats depression, for example - even if you have a major depression. A major depression is a serious condition in which people have a very negative outlook on life, and may even become suicidal.
People with depression generally have lower zinc levels in their body...
The higher your overall zinc concentration in your blood, moreover, the less likely you're depressed. When rats are fed a diet that's deprived of zinc, for example, they get depressed, derive less pleasure from any activity in general, and have increased anxiety levels.
Got a depression that's resistant to treatment? Zinc may there as well.
Even if you have a serious mental condition called "psychosis" - wherein contact is lost with reality - zinc may help.
In patients of several types of psychiatric disorders, additionally, such as "psychosis", "bipolar disorder", and "schizophrenia" overall zinc levels are lower. Don't worry about remembering the names of these conditions though.
Even if you're obsessive or compulsive, zinc can also lower that propensity and behavior.
There's more?
Yes...
Overweight or obese people often have lower mood levels compared to the general population. Zinc helps in that area. It's almost unbelievable that this $50 per year intervention that possibly cures depression (if you've got a zinc deficiency) is not used and tested for on a much wider scale.
Done yet?
No...
Zinc helps with your relaxation. Almost anyone can benefit from more relaxation in modern society.
How?
There's a delicate balance between the "GABA" and "glutamate" signaling substances in the human brain. The former is related to relaxation, while the latter is more stimulating. Zinc inhibits the activity of the more stimulating "glutamate" system so that you become more relaxed.
Zinc can even lower symptoms of anxiety.
Why?
If you've got anxiety issues, it's probable that you've got high copper levels in your tissues as well. Zinc and copper can compete with each other's absorption.
If you're really anxious all the time, your copper levels might simply be too high while zinc levels are too low. Copper has a very stimulative effect on your nervous system and mind. People with high copper levels are more prone to be violent, for example.
Taking in more zinc can correct a copper imbalance, and thus make you more relaxed overall.
How about using zinc if you're healthy?
There are indications that zinc can improve mood even in healthy people, and thus, if you don't have a depression. Everyone can thus benefit from having their zinc levels optimized.
And when you think things couldn't become any better: - Zinc boosts cognitive performance, such as memory.[145; 146; 147; 148; 149; 150; 151; 152; 153; 154; 155; 156; 312]
That's great to know...
If you're deficient in zinc, you'll have an impairment in your memory. The same thing happens when you consume too much zinc. You're fine if and only if you use an optimal zinc dose.
Zinc improves cognitive performance in children, even if they don't have a deficiency. If you're older though, such as 70 years old, zinc improves your brain capacity as well.
The higher the zinc levels in your blood, the better your cognitive performance tends to be.
By the way, for babies and toddlers who are reading this blog: zinc increase your motor development and playfulness. For their parents: yes, the minerals your kids take in do matter.
There's more:
Zinc increases your reaction time independent of age. Of course, reaction time is typically considered an increase in cognitive performance. Reaction time is nonetheless also very useful for improving your athletic performance.
A quicker response time helps in any sport that emphasizes skill.
Zinc also stimulates increases in a compound called "BDNF", which is an abbreviation of "Brain-Derived Neurotrophic Factor". BDNF is specifically related to the creation of new nerve cells. If you have optimal zinc levels, your body is thus better able to create such cells.
How about zinc's role in brain diseases?
There are indications that zinc even works for retrieving some of your cognitive function after you've had a stroke.
In other diseases, such as Alzheimer's disease (which is a form of dementia), zinc deficiency plays an essential role too. People with Alzheimer's often have excessive copper levels, which can be counteracted by zinc.
Overall, you thus need zinc levels to keep your brain healthy.
Now you know why I began the introduction of this blog post about the relationship between brain-stimulating nutrients such as zinc and our exceptional human brain development. - Zinc decreases pain sensations.[406; 407; 408; 409; 410]
That's good news!
Let's start with women again...
If you're a woman, zinc may make your period less painful. The duration of the pain during your period also decreases.
How?
A certain receptor in the brain, called the "NMDA receptor", may play a major role in pain sensations--although more (human) research is needed on this subject.
That NMDA receptor and system are positively influenced by having sufficient zinc levels.
The effects of zinc are not secluded to women's periods, however. People with pain in their muscles generally have lower zinc levels in their bodies. What about other types of pain?
Zinc may also help you deal with the pain of coming off addictive substances, or chronic cancer pain...
The effect of zinc on pain management seems very promising overall. If you're in pain make sure to also include sunlight (best) or red light therapy (good) which has been proven to work for that purpose. - Zinc may help you eat more.[411; 412; 413; 414; 415]
Do your kids not want to eat? Give them zinc!
The effect seems to be especially potent in boys, who increase their daily calorie consumption from 1,280 to 1,880 per day. That's a huge increase of almost 50%...
As I've stated before, zinc may even play a major role in averting anorexia - again, by stimulating appetite.
Don't worry about zinc making you fat through stimulating appetite though: properly using nutrients is a key effect of zinc. An example of properly using nutrients is correctly managing your blood glucose, which I've mentioned before.
An increased nutritional intake does not automatically mean that you're getting fat--eating more can entail health improvements too.
Is that all?
No...
There's more: zinc also plays a major role in many diseases. I've already mentioned cancer and Alzheimer's, but let's consider other diseases that are influenced by zinc:
- Zinc deficiency may (co-)cause the development of autism.[236; 237]
When measured, for example, children with autism have lower zinc levels in their teeth, nails, and hair.
Even during pregnancy, mothers who have low zinc levels are more prone to have autistic children. Zinc is hypothesized to be crucial in the proper development of the fetus during pregnancy.
An improperly functioning gut also plays a major role in the development of autism - and you've learned earlier that zinc is necessary for proper gut functioning.
Autism is a brain disease. When you combine that fact with the knowledge that you need zinc for a properly functioning brain, you may infer that zinc may help prevent autism.
Of course, many variables determine whether a child ends up with autism. - Zinc plays a role in neurological degeneration in general.[240; 241; 242; 243; 244; 245; 246; 247; 248; 249]
I mentioned a few nervous system disorders before such as Alzheimer's.
There's even more evidence regarding zinc and your brain:
Parkinson's another nervous system disease affected by zinc. People who have Parkinson's, for example, have lower zinc levels in their blood and brain. It's not yet known to what extent these low zinc levels are a cause or rather an effect of Parkinson's.
I hope you're beginning to see a pattern here though: many diseases are associated with having lower zinc levels in your brain.
There're more:
Seizures may also be inhibited by having optimal zinc levels in your body.
Additionally, zinc plays a vital role in the recovery after a traumatic brain injury. Zinc may reduce your chances for depression after such an injury.
How about healthy people?
Without sufficient zinc, your memory will not work as well as it should as nerve cells can die. Zinc may also protect your brain against toxins, such as aluminum (although these effects have mainly been demonstrated on rats).
Even the speed of aging of your brain is affected by zinc. Overall, zinc is thus not only necessary for brain health - which I concluded before - but for preventing brain diseases as well.
But let's exit thinking our mind and get "down to earth": - Diarrhea can be prevented with adequate zinc consumption.[251; 252; 253; 254]
Yes, really!
The period that you're having diarrhea will also be shorter with sufficient zinc in your diet. The stability (or texture) of your stools goes up, while the frequency of having to visit the toilet goes down while having adequate zinc.
That's a win-win...
You might be thinking: "what has diarrhea to do with me?"
Diarrhea is a disease that can be life-threatening. People die of diarrhea because they lose too many fluids (and minerals) in their body. Diarrhea mostly affects poorer countries.
(If you're living in a poorer country, you're more prone to be subjected to bad sanitary conditions that cause diarrhea. You're also more at risk for having zinc deficiencies in poorer countries, which exacerbates diarrhea.)
It's estimated that zinc supplementation alone can save 23% of people from dying of diarrhea. 1.23 million people die from diarrhea on a yearly basis - so diarrhea is not the side-issue many expect it to be.
Really?
Yes...
Let me make a simple calculation for you:
760,000 of these 1.23 million people are children. Take 23% percent of these numbers, and you'll conclude that inexpensive zinc tablets can thus save 300,000 people each year, among which are 190,000 children.
Zinc can even lower the reliance you need to have on other prescription medications commonly used to treat diarrhea. In other words, zinc can save money, and yet, hundreds of thousands of people are dying on a yearly basis due to zinc deficiencies anyway.
That fact alone is scandalous...
If you've got diarrhea you might thus want to increase your overall zinc consumption. - Zinc may play a role in a condition called "cystic fibrosis".[402; 403; 404]
Cystic fibrosis is a genetic disease that primarily affects the lungs, but can negatively influence other organ functions as well.
You guessed the answer:
Having sufficient zinc intake helps your condition if you've got cystic fibrosis. Specifically, zinc decreases the number of infections you'll have, improves your breathing capacity, your weight, and your energy intake.
That's a big win...
Immune system function may also be enhanced, while the number of required antibiotics can be reduced.
As always, zinc supplementation only helps if you're currently zinc deficient. In general, though, people with cystic fibrosis are more prone to be zinc deficient. - Zinc may play a role in multiple sclerosis, a disease in which your own immune system attacks nervous system cells in your spinal cord.[207; 238; 239]
People with multiple sclerosis have lower overall zinc levels. Other newer studies, on the contrary, show that zinc may be displayed and actually help cause multiple sclerosis.
Sadly enough, much more research is needed to fully understand the role of zinc in the emergence of multiple sclerosis. At this point, the displacement into the wrong areas of the body seems to be (partially) underlying the development of multiple sclerosis.
While zinc-deficiency might not play a role in this disease, its misuse does.
That's all?
No...
I could go on and on about different diseases that are affected by zinc.
I won't elaborate on the role of zinc in different diseases though, because reading even more text would bore you to death. Suffice it to say, I hope you'll understand that having adequate zinc levels is absolutely essential for moving (or staying) close to optimal health.
All types of diseases, ranging from Alzheimer's to cystic fibrosis and heart disease are affected by how zinc functions in your body.
The best advice I can give you is that if you're so unfortunate to be dealing with any disease described above, is to read the following sections on zinc-rich foods, zinc-deficiency, and using lab tests to double-check your zinc levels.
(Advanced explanation: the section above does not justice to the full complexity zinc has in the human body. Zinc has an effect on more than 300 enzymes and 1000 transcription factors. Zinc helps regulate cell death, deals with DNA and RNA, and regulates gene expression.)[41; 42; 43] in the brain, zinc has various effects on chloride, potassium, calcium, and sodium channels.[44; 45; 46; 47] Due to over-complication, I've left most of these mineral interactions out of this article.
Besides dopamine, which was previously treated in this section, other neurotransmitters such as glutamate, serotonin, dopamine, and adenosine are also affected by your zinc intake.[48; 49; 50; 51] Even though zinc is a trace mineral, it's hardly less important than calcium or magnesium, although the latter ones are far more well-known by the general public.)
Enough talking about diseases.
Let's move to a more positive note: food...
Hungry yet?
Then read the next installment!
I promise you, your hunger will only become worse...
Want a simple infographic that describes the 10 most important lessons I got from reading hundreds of studies on zinc? Subscribe below:
Finishing Thoughts: Many People Misunderstand Zinc's Role Because They Don't Understand Evolution
Let's put the message of this blog post, and first installment of this series, more succinctly:
I really hope you're seeing the big picture here - zinc:
- is intertwined with hormonal health and libido. Examples of hormones are testosterone and thyroid hormones.
- affects your overall cognition and adequate status is intertwined with health conditions such as Alzheimer's
- directly affects sleep quality and overall energy levels. Without adequate deep sleep, you won't perform nor feel well, or be healthy!
- helps you feel well, as well as making your brain work properly, by boosting dopamine, among others.
- increases drive to eat (in a healthy manner)
- influences many organs and bodily systems, such as circulation, your immune system, etc.
Why does one simple mineral have such widespread effects upon many domains of your health?
Simple: zinc plays a major role in human evolution. In fact, it can be argued that some of the foods humans depended on in Africa and the Mediterranean are quintessential zinc-rich foods!
Have you gotten curious about this topic?
Then check out the second and third installments of this series that venture a lot deeper into the best zinc-rich foods, deficiencies, lab testing, and a lot more!
Update: My Iron & Magnesium Series + Zinc Updtes
If you're interested in similar blog post series as these, check out my blog post series on iron and human health and magnesium and human health.
This is a post by Bart Wolbers. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MS - Cum Laude), and Clinical Health Science (MS), and is currently a health consultant at Alexfergus.com.
Found This Article Interesting? Then You Might Like:
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- Learn About The Most Effective Supplements For Your Health
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