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There’s nothing sexy about zinc.
Which is funny because it’s involved in some of the most important processes that go on in your body – especially ones that are important to men (think: testosterone, fertility, erectile dysfunction and others).
1. Helps Your Cells Grow
Zinc appears to be essential in telling cells to grow through Insulin-like Growth Factor-I (IGF-I) which can then increase Growth Hormone (GH) in your body.
Ironically, even if you give patients GH or IGF-I to treat the problem the growth failure is not reversed. This tells us that getting enough zinc in your diet is critical to hormone signaling.
2. Increases Testosterone Levels
What happens when you take healthy men in their 20’s and restrict zinc intake through diet? Their testosterone levels dropped from 39.9 to 10.6.
The same study also looked at older men (mid 50’s to mid 70’s) who were already zinc deficient and gave them a zinc supplement. Their testosterone increased from 8.3 to 16.0.
Whether it’s diet or supplementation – getting more zinc clearly plays an important role in testosterone levels.
3. Male Pattern Baldness
One thing is clear – zinc does play a role in the growth of hair follicles. In fact, a 2013 study in the Annals of Dermatology showed that all of the hair loss patients had lower zinc levels than the control group they studied.
So, if you have thinning hair or are balding you should get more zinc. Right?
Not so fast.
Remember that zinc plays a crucial role in RNA and DNA synthesis. And that means in all of your bodies cells. Also remember that your hair goes through various ‘stages’ .
What researchers have found is that high doses of zinc can inhibit what are known as the anagen and catagen phases of hair growth.
Bottom line: getting too little zinc – or too much – can lead to problems with hair loss. How you metabolize zinc may be playing a role in your hair loss.
Your best bet is to make sure your diet is dialed in with zinc rich foods (see the list below). If it is you’d want to avoid supplementation which can cause your levels to jump too high (I’ll cover another big reason to avoid supplementation below).
4. Better Heart Health
Your heart has a high metabolic activity. That also means that you can see a lot of free radicals in this muscle. Making matters worse is the fact that your heart doesn’t have a lot of capacity to fight these free radicals. So it can be susceptible to oxidative stress.
So what does zinc have to do with fighting free radicals?
Well, more than we originally thought.
Researchers actually took young piglets (a pig’s heart is very similar to a humans) and deprived them of zinc for a few days. They noticed that the concentration of the antioxidants glutathione and Vitamin E dropped alongside the zinc levels.
They also noticed that declining zinc levels caused apoptosis (programmed cell death).
Finally, even though the scientists only held back on zinc for a few days the pigs hearts recognized the shortage and ‘borrowed’ what zinc was available – but at the expense of the other organs in the body (liver, kidney, pancreas).
5. Stronger Immune System
As you get older the DNA inside your cells deteriorates which can lead to problems in your body. We now believe that zinc can play a role in slowing this process down.
In a study by Janet King, Ph.D. 18 men ate a low zinc diet based off rice for six weeks. Before, during and after the study the researchers measured the amount of DNA damage, DNA inflammation and oxidative stress.
The study proved that increasing the amount of zinc you’re getting in your diet could lower the amount of DNA strand breakage found in leukocytes (white blood cells) which are critical to your immune system function.
6. Prostate Protection
OK – things can get a little muddy when it comes to zinc and the prostate.
Early on researchers discovered that zinc levels in healthy prostates are almost 7 times higher than prostates that have cancer. So it makes sense that the more zinc you have in the prostate the healthier the prostate should be.
And this is exactly how prostate cancer and prostatitis (inflammation of the prostate) was treated for years – simply give high doses of zinc (up to 100mg per day).
But we now know that supplementing with zinc (especially at higher doses) may be making prostate problems worse.
A paper published in the Journal of the National Cancer Institute showed that taking up to 100mg of zinc supplement per day did not change the risk of prostate cancer and men who took it more doubled their risk of advanced prostate cancer compared to men who didn’t take any supplements.
While we still don’t know what might be causing these sorts of conflicting reports it’s clear that maintaining healthy zinc levels through diet is the best idea.
I would be hesitant to supplement with zinc – especially at higher doses if you have any history of prostate cancer.
7. More Fertile
If a man wants to be able to become a father he HAS to make sure he’s getting enough zinc.
So it’s no surprise that infertile males have significantly lower concentrations of zinc in their seminal plasma.
Men who consume more zinc see an increase in semen volume, more motile sperm and more normal sperm.
8. Improved Strength
You already learned that zinc helps men increase testosterone production and IGF-1 (Insulin-like Growth Factor-1). It can also cause increases in GH (Growth Hormone).
Increased testosterone and GH is great 1-2 punch to help you get stronger and recover quicker.
Researchers have also taken zinc to the lab by giving trained athletes zinc supplements for four weeks and then giving them a really hard exercise test. The group that got the extra zinc saw a greater post-workout testosterone response.
Secondly, zinc can improve the conversion of androstenedione to testosterone.
9. Improved Vision
Zinc is essential to help mobilize Vitamin A from your liver.
Also, when zinc levels are low the amount of Retinol Binding Protein (RBP) in your liver and blood drop. This affects how much Vitamin A your body absorbs and uses.
Finally, zinc is a coenzyme for Alcohol Dehydrogenase which is critical for eye function because it helps convert retinol to retinal.
10. Improved Metabolic Rate
You need zinc to properly metabolize and break down carbohydrates for your body to use as an energy source.
Sidenote: yes, you can go Keto but there are downsides to going full time Keto and carbs are neeeded for testosterone production as well.
11. The Two M’s (Memory and Mood)
NDMA (N-methyl-D-aspartate) helps control memory function in your brain. But if you get too much activation you can see brain cell death from too much calcium coming into the neuronal cells.
Zinc is a known antagonist (or blocker) of NDMA.
It’s no surprise that people low in zinc can have memory problems and mood disorders.
12. It’s An Antioxidant
We know that oxidation and chronic inflammation play a big role in the aging process and the diseases that start cropping up like heart disease, cancer, brain decline and the aging process in general.
When it comes to lowering oxidation and inflammation zinc has proven to be very effective.
Another study that gave 45mg a day of zinc gluconate found similar results: plasma levels of oxidation markers went down compared to the group that got no supplemental zinc.
13. Erectile Dysfunction
First things first, there aren’t a lot of actual studies looking at using zinc to treat erectile dysfunction. But there is other evidence to support it’s role.
First, you already know that zinc is critical to testosterone levels in your body. And testosterone is an important factor in a man’s sex drive. Which usually means more erections.
As far as studies go, in 2009 researchers gave rats 5 mg a day of a zinc supplement and it results in better sexual function. Granted, that’s animals and not humans but it is promising.
Finally, another study in 2013 didn’t look directly at zinc supplementation but did look at sense of smell and how it affects sex drive in both young and old men.
In short, they found that a lowered sense of smell can also lower sex drive. Guess what causes a lowered sense of smell? You guessed it – low zinc levels in the body.
14. More Energy And Endurance
Zinc is involved in a LOT of processes in the body. One of the most important is helping at least 100 enzymes in your body do their job.
One of the most critical is helping your body use and process the amino acids, carbohydrates and fatty acids that you get from your food. Without these nutrients you not only get sick more but can lack the energy you need.
This is one of the reasons why you can see low zinc levels in patients with adrenal problems and even chronic fatigue.
Researchers have shown that supplementing with zinc (55mg per day of zinc sulfate which equals 15mg of elemental zinc) helped kids that were already diagnosed with ADHD and were taking Ritalin (methylphenidate).
Researchers aren’t sure how zinc is helping but one of the theories is zinc’s role in the metabolism of melatonin.
Melatonin is a hormone that helps regulate another hormone called Dopamine which we already know to be an important factor in hyperactivity disorders.
Researchers took 120 healthy subjects and showed that eating more zinc-rich foods helped them fall asleep faster and improved their sleep efficiency.
How To Get More Zinc In Your Diet
The best way to get more zinc is to make sure your eating foods rich in zinc.
Bottom line – the most zinc-rich foods with the lightest caloric load are animal proteins. That’s why if you’re a vegetarian or Keto you have to be very careful.
A 3.5-ounce serving of grass fed beef will give you 4.8mg of zinc (men should be getting 11mg a day). You’ll also be getting 20 grams of protein, 10 grams of healthy fats and only 176 calories.
Pumpkin seeds are another good source of zinc. One cup will give you even more zinc than the grass fed beef at 6.6mg. But you’ll also be getting around 600 calories.
Chickpeas are another decent source of zinc with one cup giving you 2.5 mg of zinc but also coming in at 729 calories.
My point here is that for vegetarians you can get enough zinc through your diet. But it will be tough to do that without gaining weight because of the high calorie count of some of these foods. Also, you’ll be missing out on other nutrients that are important for health.
Other zinc-rich foods include:
- Oyster (1 medium) = 5 mg zinc
- Alaskan Crab: 3.5 ounces = 7.6 mg zinc
- Cheddar Cheese: 100 grams = 3.1 mg zinc
- Lamb: 3 ounces = 6.7mg zinc
- Cashews: 1 ounce = 1.6 mg zinc
- Dark Chocolate: 100 grams = 3.3 mg zinc
- Mushrooms: 1 cup = 1.4 mg zinc
- Spinach: 1 cup = 1.4 mg zinc
- Chicken: 100 grams = 1 mg zinc
- Baked russet potato with skin: 100 grams = 0.49mg
Million Dollar Question: Should You Supplement With Zinc?
You really have to look at your diet.
If it’s on point you’re likely getting enough zinc.
There are exceptions to that.
For example, during certain times of the year I’ll cut my calories back (cutting) to try to trim body fat. Because I’m eating less food there’s a better chance I’m not getting enough zinc so I’ll take 15mg a day as insurance.
But What About Copper Deficiency?
If you’ve looked around at all you’ve likely heard that supplementing with zinc can cause copper deficiency because high zinc intake can increase the amount of an intestinal cell protein called metallothionein that is made by your body.
Metallothionein has a stronger affinity for copper – so it can bind it and reduce absorption.
Copper deficiency has only been shown when people take high dose zinc supplements (50mg or more per day, long term). At much lower doses (10 mg/day for 8 weeks) researchers saw copper/zinc blood ratio’s return to normal.
The only way to know for SURE if you need to supplement is to get your blood levels measured. If you and your doctor decide it’s the right way to go the bottom line is to really keep the dosage on the low side. I would suggest staying under 15 mg a day.
What Type Of Zinc Supplement Is Best?
There are all sorts of different ‘salt forms’ of zinc: zinc acetate, zinc orotate, zinc sulfate, zinc gluconate and the list goes on.
So which one is best?
From the evidence I’ve seen it may not matter.
There’s a lot more to how much zinc your body will actually absorb than the salt form it comes in. This is one of those things supplement companies fail to mention.
- your body absorbs about 20-40% of zinc in food but animal foods are absorbed at twice the rate than zinc from plants (more bad news for vegetarians)
- your body also can’t technically ’store’ zinc. But, metallothionines in your gut cells can hold small reserves and transport them in your body as needed. These gut cells are also capable of adjusting the amount of zinc you absorb by 15-40%.
- protein-rich foods increase zinc absorption
- foods that contain phytates (cereals, rice, corn and grains) lower zinc absorption
- as you age you also absorb less zinc
- the more zinc you have in your body the less your body actually absorbs. The opposite is also true.
So you can see that with all these variables there is no perfect form of zinc or perfect amount to take.
However, one small research study took 15 healthy young adults and gave them 10 mg of various zinc supplements to test the bioavailability (a fancy way of saying how much zinc is actually ‘available’ for your body to use). They found the following:
- Zinc citrate = 61.3% available
- Zinc gluconate = 60.9% available
- Zinc oxide = 49.9% available
Like I said above, base your decision to supplement with zinc based off your diet.
Most days I know I’m eating zinc-rich foods – so I don’t worry about supplementing.
Other times when I’m cutting I may miss the mark with my diet so I’ll supplement with low doses of zinc.
I wouldn’t ever recommend going above 15mg per day.