I am starting a long post on minerals. Why?

Why not for #1.

But secondly they are so important for overall health, metabolic healthy and more.

Will continue adding new minerals to this post weekly.

Today’s miners: ZINC

The Discovery of Zinc Deficiency

In 1958, a 21-year-old man in an Iranian village visited Ananda Prasad, a medical doctor who had recently arrived from India. Prasad and his team thought the man looked like a 10-year-old child.

The man told the story of how he started working in the rice fields when he was 11. Very soon after that he began to feel easily fatigued. He had difficulty breathing. He suffered from heart palpitations, when the heart skips a beat, beats irregularly, or flutters. For the last four years since he was 17 years old, he was totally unable to work in the rice fields, and he felt like he had a fever every night.

Prasad and his team asked him what he ate, and it turned out that he ate a diet that was almost entirely whole wheat bread, with a little bit of milk, a little bit of potatoes, very few fruits and vegetables, no eggs, and no meat. He also ate a quarter pound of clay every day.

The man was short, and his genitalia looked as if he had never gone through puberty. Prasad and his team poked around looking for the man’s prostate, but couldn’t find one. He had no pubic hair, no facial hair, no armpit hair, and his spleen was enlarged.

The man had blood measurements indicating iron-deficiency anemia, so they treated him with iron for two weeks. He put on some weight, his strength came back, and his anemia was corrected, but his sex characteristics had not changed.

He left their practice and came back eight months later after eating meat, along with fruit and vegetables every day, and all his sex characteristics had, at that point, became normal.

Prasad and his team then looked for other people suffering from the same problems in the village. They found eleven such people, all eating a similar diet and usually having a pretty significant intake of clay. In one of them, they were able to measure the blood concentrations of zinc and found them to be low. In all eleven cases, just as in the first man, eating meat fully corrected their medical problems.

Within five years, Prasad and his team found a very similar syndrome in Egypt. The patients stopped growing earlier than they should have, felt lethargic, had underdeveloped genitalia and rough skin, and got sick far more often than they should have. This time, Prasad’s team showed they could completely reverse all these problems with zinc supplements.

Thus, in 1963, Prasad’s team gave us the first clear evidence of human zinc deficiency, and hardly more than a decade later, in 1974, the first RDA for zinc was established.

Zinc Deficiency Today

Today, zinc deficiency is now appreciated to be one of the most common health problems in the world. The World Health Organization estimates that half the world’s population is at risk of zinc deficiency. In European and North American countries, 1-13% of the population are at risk. In Asian, African, Middle Eastern, and Mediterranean regions, 68-95% are at risk.

When children are affected, poor growth and impaired sexual development may manifest, as in the first cases that Prasad’s team discovered. Most commonly, zinc deficiency involves frequent infection, and skin problems ranging from dry skin, to acne, to red blisters and pustules.

One of the most common problems in the world is chronic diarrhea. Zinc deficiency is thought to be both a cause and consequence of diarrhea. Zinc deficiency makes you vulnerable to infection, the infection causes diarrhea, and the diarrhea causes poor absorption of zinc. A vicious cycle ensues.

What happens in more moderate or borderline deficiency?

When researchers put healthy volunteers on zinc-deficient diets, the most common first symptom was patches of dry skin. In some volunteers, the dry skin gave way to severe acne. As the deficiency progressed, it caused sore throat, diarrhea, poor appetite, and loss of lean body mass.

In fact, their bodies shed lean mass on purpose to keep the zinc concentration within their tissues from falling. Without zinc, you shrink.

The Many Roles of Zinc

In the last half century, we have learned a tremendous amount about the role that zinc plays in our bodies, and this allows us to see many other processes that might fail in deficiency or that might benefit from zinc-rich foods or from zinc supplements:

Zinc is needed to allow vitamins A and D, thyroid hormone, stress hormones, and sex hormones to carry out their functions. Without zinc, we can become resistant to the effects of any of these substances.
Zinc has an especially intimate relationship with vitamin A, being required to carry it in the blood, to activate it, to use it for vision, and to use it for cellular communication.
Like magnesium, zinc is needed for the production of all proteins. Since everything in the body is either a protein or is made using proteins, this makes zinc, like magnesium, necessary for literally everything that happens in the body.
Zinc activates enzymes involved in digestion, regulating the balance of acidity and alkalinity, antioxidant protection, thyroid hormone production, and the immune system’s defense against pathogens.
Zinc is required for the production of nitric oxide, which aids in blood flow in many contexts, protects against high blood pressure, contributes to sexual arousal in both sexes, and maintains erections in men.
Zinc is needed for the body to defend itself against heavy metals such as mercury and lead, by allowing the body to respond to them by making a protein that binds them up and prevents them from causing toxicity.
Some of our zinc is stored with insulin. When insulin is released by the pancreas in response to carbohydrate, the stored zinc is also released. The zinc shuts off an opposing hormone called glucagon, keeps insulin in the blood longer, and acts on insulin receptors to make cells more sensitive to this hormone. Together, this helps keep blood sugar stable and prevents the development of insulin resistance and diabetes.
Zinc supplements have been shown to decrease infection, inflammation, and oxidative stress, to improve blood sugar, and to reduce the incidence of age-related macular degeneration, a major cause of blindness in the elderly.

Any of these things, then, could be reasons to try supplementing with a modest dose of zinc or to try improving your intake of zinc-rich foods, even if you haven’t experienced the classical symptoms of deficiency, such as dry skin, acne, sore throat, and diarrhea.

How Much Zinc Do We Need?

The Institute of Medicine set the current recommendations for zinc in 2001. For infants six months old and younger, an adequate intake was set at 2 milligrams per day (mg/d) based on the average intake of exclusively breastfed infants.

For all other age groups, an RDA was set primarily based on the amount needed to prevent us from losing zinc from our bodies over time. In infants over six months, children, and adolescents, the Institute also looked at the amount needed to support growth, and this generally agreed with the amount needed to offset losses.

The RDA was set at 3 mg/d for infants 7 months or older and for children up to 3 years; 5 mg/d for children aged 4-8; and 8 mg/d for adolescents aged 9-13.

From age 14 and on, the RDA diverges by sex. For girls aged 14-18, the RDA is 9 mg/d; for boys, it is 11 mg/d.

For women aged 19 or older, the RDA is 8 mg/d. For men, it is 11 mg/d.

To account for accumulation of zinc within the fetus, the RDA for pregnant women increases to 11 mg/d for women aged 19 and older, and 12 mg/d for girls aged 14-18. To account for losses in breastmilk, it increases to 12 mg/d in lactating women aged 19 and older, and to 13 mg/d in lactating girls aged 14-18.

Although there is no special RDA for bodybuilders or for men who ejaculate frequently, putting on ten pounds of muscle in one month would require an extra 3 mg/d; putting on ten pounds of muscle in three months would require an extra 1 mg/d; and each male ejaculation requires an additional 3 mg.

The Threat of Phytate

The main contributor to zinc deficiency worldwide, apart from diarrhea-causing infections, is a diet low in animal products and high in a plant compound known as phytate, which is found most abundantly in whole grains, nuts, seeds, and legumes. Legumes include foods such as lentils, beans, and peas.

Phytate is largely made of phosphorus, and it binds to minerals like iron, zinc, calcium, magnesium, and manganese. From a plant’s perspective, it’s a way of storing phosphorous and other minerals, like zinc, when times are not right to sprout and grow into a plant. And so seeds will sense the conditions of the environment that are ripe for sprouting, and if the seed “believes” that it’s a good time to grow a plant because there’s a high likelihood of success, then the phytate is broken down and releases the zinc and the other minerals to become more bioavailable.

Although the Institute of Medicine did not make a special RDA for vegans or vegetarians, it stated in the 2001 report that individuals getting their zinc exclusively from plants may need 50% more. That would raise the adult RDA to 12 mg/d for women eating a plant-based diet and to 16.5 mg/d for men eating a plant-based diet.

However, more recent computer modeling of zinc absorption has suggested that several servings per day of phytate-rich foods would raise the zinc requirement to 100 mg/d, which is almost impossible to get from food.

We can reduce the amount of phytate in our plant foods by sprouting them, or by mimicking the conditions that cause sprouting, by fermenting them or by soaking them overnight in a warm and slightly acidic medium. This reduces, but does not eliminate, their phytate content.

Animal Protein and Sour Acids Enhance Zinc Absorption

While phytate is the major concern for zinc absorption, other factors play a role as well. Protein from meat, fish, shellfish, eggs, and whey enhance zinc absorption. This is not true for casein, the dominant protein in cheese, which may actually hurt zinc absorption. Sour acids also enhance zinc absorption. These include lactate, found in yogurt, kefir, and many fermented plant foods; citrate, rich in citrus fruits; and malate, rich in non-citrus fruits.

Overall, zinc is five times more absorbable from the average animal food than from the average plant food.

Zinc is likely very absorbable from fruits as a result of the sour acids and lack of phytate, but fruits aren’t very high in zinc. Cheese is rich in zinc, but the zinc is probably less absorbable than from other animal foods as a result of the casein protein. The foods richest in zinc are oysters, at the top, and red meat, a distant second, but one that still towers over most other foods. Because of their protein composition and lack of phytate, the zinc in oysters and red meat is especially absorbable.

Zinc in Foods: General Principles

When looking at the foods in our five tiers, we need to keep a handful of things in mind:

The zinc in animal foods is more reliable than the zinc in plant foods.
The zinc in non-cheese animal foods is especially reliable, and the zinc in whole grains, nuts, seeds, and legumes is especially unreliable.
Oysters and red meat are richest in zinc, and the leaner cuts of meat are richer in zinc than the fattier cuts. For poultry, darker cuts of meat are richer in zinc than lighter cuts of meat, but the trimmable fat and skin from these cuts is lowest in zinc.
Although the zinc in whole grains, nuts, seeds, and legumes is unreliable, other plant foods, such as fruits and vegetables, are very low in zinc.
We can increase the absorbability of zinc in whole grains, nuts, seeds, and legumes by sprouting, soaking, or fermenting them.
A phytate-rich diet has been suggested to increase the zinc requirement anywhere from 50% to 10-fold. Unfortunately it is impossible to know exactly how much phytate is neutralized during sprouting, soaking and fermenting. Therefore, it is wise to consume zinc-rich foods away from phytate-rich foods. If you are relying exclusively on plant foods for zinc, be cautious about the need to supplement if you experience any problems that could be a result of deficiency.
Zinc in Foods: The Five Tiers

The target for our five tiers is 12 mg, which covers the RDA for all adults aged 19 and older.

Tier 1

Tier 1 foods provide at least 12 mg per 100 grams, allowing us to hit the target with a single serving per day.

Tier 1 has three foods: oysters, wheat germ, and calf liver.

Tier 2

Tier 2 foods provide at least 4 mg per 100 grams, allowing us to hit the target with 2-3 servings per day.

Tier 2 contains some yummy treats: maple sugar, maple syrup, cocoa powder, and any chocolate product that is at least 40% cocoa.

Tier 2 contains all ground beef and many other cuts of fresh beef: chuck, brisket, round knuckle, bottom round, eye of round, tip round, ribeye, sirloin, flank, the large end of ribs, choice tenderloin, choice top loin, and the following cuts if the fat is trimmed off: shortribs, top round, and grass-fed strip steaks.

Several processed beef products (bologna, roast beef spread, pastrami, jellied beef, and smoked chopped beef) and two other processed meats (turkey pepperoni and pork salami) also make it into tier 2.

Tier 2 contains several cuts of lamb: most shoulder cuts, foreshank, leg shank half, other cuts of the leg with the fat trimmed off, and US choice rib with the fat trimmed off.

Several types of offal make it into tier 2: lamb liver, pork liver and pork liver cheese, chicken heart, and turkey neck.

Three cuts of veal (shank, shoulder blade, and whole shoulder) and two cuts of bison (ground bison and shoulder clod) make it into tier 2.

Tier 2 contains most cuts of emu (though ground emu and flat fillet are in tier 3).

Tier 2 also contains beefalo, goat, caribou, ostrich, ground elk, and ground deer.

For seafood, tier 2 has most crab (except queen, which is in tier 3), and spiny lobster.

A number of cheeses make it into tier 2: Swiss, edam, fontina, gouda, gruyere, queso chihuahua, nonfat mozzarella, grated parmesan, reduced-fat cheddar, and tilsit.

Tier 2 contains some beans (hyacinth, adzuki, soy, black, cranberry, navy, mature white, winged, and yardlong), and some other legumes and legume products (catjang cowpeas, lentils, lupins, Virginia peanuts, peanut flour, and peanut spread).

All sesame or sunflower seeds and products made from them, flax seeds, and the dried kernels of watermelon, safflower, pumpkin, and squash seeds, make it into tier 2.

Tier 2 has some grain products: wheat bran, pre-1968 varieties of whole wheat, rice bran, wild rice, rye and dark rye flour, oats, and durum wheat.

It also has four nuts: cashews and cashew butter, pine nuts, pecans, and Brazil nuts.

Finally, tier 2 has one vegetable: palm hearts.

Tier 3

Tier 3 foods provide at least 2.4 mg per 100 grams, allowing us to hit the target with 4-5 servings per day.

Tier 3 contains some cuts of beef: short ribs with the fat, the small end of ribs, top round with the fat, short loin, and prime and select tenderloin.

Tier 3 contains some cuts of lamb: most leg cuts with the fat (except the foreshank and shank half, which are in tier 2), loin, rib (except US choice rib, which is in tier 2), US choice shoulder arm, and ground lamb.

It contains some cuts of pork, including many cuts of ham (though most are in tier 4, and some are in tier 5), most shoulder cuts, loin blade with the fat trimmed off, country-style ribs, spareribs, and leg cap steak.

For turkey, tier 3 includes the back, leg, or dark meat of young hens and toms, and the leg or dark meat of fryer-roasters.

Tier 3 has four cuts of veal (ground, rib, shoulder arm, and sirloin) and two cuts of emu (flat fillet and ground emu).

Two crustaceans, queen crab and northern lobster, make it into tier 3.

Tier 3 contains most bison (though ground bison and shoulder clod are in tier 2), as well as quail and pigeon without the skin, horse, and moose.

This tier contains a fairly large collection of offal from beef (pancreas and tongue), pork (heart, kidneys, pancreas, spleen, tongue, and braunschweiger), veal (pancreas and tongue), chicken (giblets, gizzard, liver, and neck), turkey (gizzard and heart), the livers of duck and goose, pate, and lamb spleen.

It also has a number of processed meats: corned beef brisket, “lite” bratwurst sausage, turkey franks, chorizo, fat-free frankfurters, honey roll sausage, turkey bacon, hard and Genoa salami, peppered pork loaf, beef and pork pepperoni.

Tier 3 contains the largest collection of cheeses: blue, brick, caraway, cheshire, colby, feta, queso anejo, queso asadero, monterey, muenster, port de salut, provolone, romano, shredded and hard parmesan (though grated parmesan is in tier 2), cheddar (though reduced-fat cheddar is in tier 2), and most mozzarella (though nonfat mozzarella is in tier 2, and whole milk low-moisture mozzarella is in tier 4).

Tier 3 contains a number of wheat products (whole grain flour, hard red spring and winter, hard white, soft red winter white, and soft white), and a number of other grain products: hulled barley, whole-groat buckwheat flour, oat bran, partially debranned oat flour, triticale, and whole-grain triticale flour.










A number of beans (kidney, pink, small white, yellow, fava, mature and thin-seeded baby lima, mung, and mungo) and other legumes and legume products (chickpeas and chickpea flour, common cowpeas, peanut butter, Valencia peanuts, split peas, miso, and natto) make it into tier 3.

Tier 3 has five nuts: almonds and almond butter, butternuts, dried Japanese chestnuts, pili nuts, and walnuts.

Nutritional yeast in the quantity of three tablespoons makes it into tier 3.

Finally, tier 3 also contains chia seeds, and a single vegetable: fireweed leaves.

Tier 4

Tier 4 foods provide at least 1.43 mg per 100 grams, allowing us to hit the target with 1-2 pounds of food per day.

Tier 4 contains many cuts of chicken: for broilers and fryers, it contains the back meat or wing meat without the skin, and the dark meat with or without the skin; for roasting and stewing chickens, it contains the dark meat without the skin.

It also contains many cuts of turkey: it has ground turkey; for fryer-roasters it has the back meat, the wing meat, and the skin of any cut; for young hens, it has the breast meat; for young toms, it has the meat of the breast and wing.

Some cuts from other poultry animals also make it into tier 4: domesticated duck meat without the skin, goose meat with or without the skin, quail and pigeon meat with the skin, and pheasant leg.

Tier 4 also contains many cuts of pork: most cuts of ham, though some are in tiers 3 or 5; ground pork, blade loin, center loin, top loin, sirloin, backribs, center rib, arm picnic, shoulder breast, and shoulder petite tender.

Tier 4 is home to three cuts of veal (breast, top round, and loin), most cuts of deer and elk (though ground deer and elk are found in tier 2), water buffalo, and rabbit.

For seafood, tier 4 has four fish (anchovies, eel, smelt, and sunfish) and six shellfish (conch, cuttlefish, mussels, octopus, squid, and whelk).

Tier 4 has a number of offal cuts: for beef, it has heart, kidney, lung, spleen, and thymus; for lamb, it has heart, kidney, lung, pancreas, and tongue; for veal, it has kidney, spleen, and thymus; for pork, it has lung, stomach, tail, and liverwurst); for turkey, it has the liver.

Many processed meats make it into tier 4: beef or pork breakfast strips, pork shoulder blade roll, pickled pork hock, turkey ham, barbecue loaf, most sausages (though some are in tiers 3 and 5) some bologna products (though some are in tier 5, and regular beef bologna is in tier 2), many frankfurters (though some are in tiers 3 and 5), turkey pastrami, pickle and pimiento loaf, picnic loaf, turkey roll, and deli turkey.

Whole turkey eggs, the yolks of chicken eggs, and six cheeses (brie, camembert, hard goat, lumburger, roquefort, and low-moisture whole milk mozzarella) make it into tier 4.

Many grain products make it into tier 4: all barley products except hulled barley, which is in tier 3; buckwheat, bulgur, corn and all whole-grain corn products, millet, brown rice and flour made from it, light and medium rye flour, high-protein (13%) white flour, and sprouted wheat.

Tier 4 has four beans (French, great northern, mature pinto, and moth), soybean curd cheese, some tofu (hard, raw firm, salted and fermented), and three other legume products (hummus, Spanish peanuts, sprouted lentils).

It also contains dried, unsweetened coconut meat, two nuts (hazelnuts and pistachios), one seed (dried breadnuttree seeds), and three vegetables (irishmoss seaweed, lemon grass, and wasabi root).

Tier 5

Tier 5 foods provide at least 0.53 mg per 100 grams, allowing us to hit the target with 3-5 pounds of food per day.

Tier 5 is distinguished by being the only tier with a large number of veggies: alfalfa sprouts, amaranth leaves, arrowroot, asparagus, bitter gourd pods, bamboo shoots, broccoli raab, calabash, cauliflower, chayote, chives, chyrsanthemum leaves and garland, endive, eppaw, fava beans in the pod, fiddlehead ferns, garlic, grape leaves, horseradish-tree leafy tips, jute potherb, leeks, okra, onions, parsley, parsnips, peppers (ancho, hot chile, pasilla), radicchio, radish sprouts, spinach, taro shoots, waxgourd, winged bean leaves and tubers, and zucchini.

Having given tier 5 its honor for carrying so many veggies, let’s continue with the rest of the plant foods before we go over the animal foods.

Tier 5 contains a large collection of mushrooms (cloud ears, pepeao, oyster, brown, Italian, Crimini, enoki, maitake, portabella, shiitake, and white), three types of seaweed (agar, kelp, and laver), five beans (sprouted navy, young pinto, broad, lima, and sprouted and unsprouted soy), four other legumes (young cowpeas, edamame, sprouted and unsprouted peas, and pigeonpeas), and a handful of other legume products (carob flour, soy sauce, tempeh, and several types of tofu [soft, raw regular, okara, firm, and extra firm]).

Avocados, wild blueberries, and blackberries make it into tier 5.

Tier 5 has three seeds (raw breadnuttree seeds, breadfruit seeds, and dried lotus seeds), a decent collection of nuts and nut products (acorns and acorn flour, almond paste, Chinese chestnuts, raw Japanese chestnuts, raw and unpeeled European chestnuts, and macadamia nuts), and is home to all coconut products except dried, unsweetened coconut meat (tier 4) and coconut water (doesn’t make the cut).

Tier 5 also contains fresh and frozen corn, plus a number of refined grain products: degermed cornmeal, white rice flour, white rice, vital wheat gluten, most white flour (though high-protein 13% white flour is in tier 4), and most packaged foods made with white flour as the overwhelming ingredient.

Tier 5 also contains molasses, a yummy treat!

Many sugary drinks, packaged foods, and fast foods make it into tier 5, but many of them don’t make the cut.

And now, back to the animal foods!

Tier 5 has the largest collection of fish out of any tier: bass, bluefish, burbot, butterfish, carp, catfish, black and red caviar, drum, gefiltefish, herring, link, mackerel, milkfish, mullet, perch, pike, pompano, pout, roe, salmon, spot, sturgeon, sucker, swordfish, trout, tuna, whitefish, whiting, wolffish, and yellowtail.

Several shellfish and other crustaceans also make it into tier 5: abalone, clams, crayfish, scallops, shrimp, and snails.

Tier 5 has plenty of chicken: ground chicken; for broilers or fryers, it has back or wing meat with the skin, the skin of any cut, and the breast; for roasting or stewing chickens, it has light meat without the skin; and it has the meat from capons and cornish game hens.

Tier 5 also has some turkey (the breast meat from fryer-roasters, the wing meat with the skin from young hens, and the skin of any cut from young hens and toms), as well as meat from several other poultry animals (wild duck, domesticated duck meat with the skin, guinea hen, and most cuts of pheasant, though pheasant leg is in tier 4).

Tier 5 pork cuts include bacon, some cuts of ham (though most are in tier 4 and some are in tier 3), belly, and top loin chops from enhanced pork.

While most fats do not contain much zinc, the fat trimmed from cuts of beef, pork, veal, and lamb makes it into tier 5.

Tier 5 also includes antelope, frogs legs, and turtles.

A number of processed meats find their home in tier 5: some bologna products (though some are in tier 4, and regular beef bologna is in tier 2); sausage (bloodsausage and smoked link), light meat chicken or turkey roll, chicken spread, some frankfurters (though many are in tier 4 and some are in tier 3), mother’s loaf, olive loaf, deli turkey, and pork scrapple.

Some offal cuts also find their home in tier 5: from beef, brain and tripe; from lamb, brain; from veal, brain, heart, and lungs; from pork, brain, chitterlings, feet, jowl, and head cheese.

Finally, tier 5 includes several cheeses (cream cheese, gjetost, soft and semisoft goat, neufchatel, and ricotta) as well as yogurt, half and half, and sheep milk.

Don’t Make the Cut

Foods don’t make the cut if they provide less than 0.53 mg per 100 grams. These foods won’t directly cause zinc deficiency, but if you don’t get your zinc from the first three tiers and instead rely on tiers 4 and 5 for most of it, the foods that don’t make the cut will take up desperately needed room in your diet and may prevent you from meeting the target.

Over 200 vegetables and 100 fruits don’t make the cut. Generally speaking, if they weren’t listed in the five tiers (and most of them were in tier 5), they don’t make it.

When following our standard approach to consider 2 grams of a spice a serving instead of 100 grams, no spices make the cut.

Honey fails to make the cut by a margin: it comes with 0.7 mg zinc per 100 grams, but needed 1.0 mg to make it into tier 5.

Granulated sugar, by contrast, failed to even enter the contest: it just flat out has zero zinc.

Most white flour makes it into tier 5, and high-protein white flour makes it into tier 4. So, many products that are very high in flour but lower in sugar will carry a significant amount of zinc, while those that have very little flour but lots of sugar will have very little zinc.

Foods made with white flour but sweetened with molasses, maple sugar, or maple syrup may actually be decent sources of zinc.

While the fat trimmed from the meats of beef, pork, veal, and lamb makes it into tier 5, all other fats and oils fail to make the cut, and that includes fats that are rendered from these meat fats to remove the solids, such as lard and tallow.

Egg whites and milk fail to make the cut.

Coconut water and most coffee, tea, energy drinks, sugary drinks, and alcoholic drinks fail to make the cut.

Almost 40 fish fail to make the cut, and those include any of the fish that weren’t explicitly mentioned above.

Pig ears and several grain products (cornstarch, arrowroot flour, and tapioca pearls) also fail to make the cut.

What Happened in That First Case of Zinc Deficiency?

In the original case of zinc deficiency discovered in the Iranian village, the man ate mostly whole wheat bread, with a little bit of milk, a little bit of potatoes, very few fruits and vegetables, no eggs, and no meat. He also ate a quarter pound of clay every day.

After analyzing the five tiers of foods, what can we say about the cause of his zinc deficiency?

Clay is rich in certain minerals, including zinc, and in fact one of the risks of eating clay is that you could theoretically overdose on zinc. So he probably ate clay because he was deficient in zinc, and maybe other minerals like iron.

Potatoes, milk, and most fruits and vegetables are poor sources of zinc, so the presence of a tiny amount of these in his diet doesn’t matter that much.

The lack of meat in his diet certainly contributed to a much lower zinc intake than he would have had if he had been eating meat regularly, and indeed this man and the other 11 zinc-deficient patients in his village all got better when they started eating meat.

But this doesn’t fully explain the story. What about the fact that his diet was almost entirely made of whole wheat?

Whole wheat has plenty of zinc. Most whole wheat products make it into tier 3, where 3-5 servings per day would theoretically meet the zinc requirement. In fact, prior to the introduction of modern wheat varieties in 1968, whole wheat was 36% richer in zinc than it is now.

It must be the case that the phytate from the whole wheat increased his zinc requirement beyond what the whole wheat could provide. Since animal protein increases zinc absorption, the lack of animal protein in his diet made the zinc from the whole wheat even less absorbable.

The RDA for adult men is 11 mg/d. The 2001 RDA report suggested that someone getting their zinc exclusively from plants may require 50% more, which would be 16.5 mg/d. Obtaining this would require only 1400 Calories of pre-1968 wheat, which is not that many calories for a young man working in the rice fields.

Granted, by the time he was too lethargic to work, he probably wasn’t eating 1400 Calories, but this can’t explain how he developed the deficiency in the first place.

That this man became so zinc deficient that he failed to go through puberty by age 21 suggests that a phytate-rich diet raises the zinc requirement by more than 50%, perhaps closer to the 10-fold effect proposed by more recent computer modeling.

In short, a diet rich in whole grains provided phytate, the principle inhibitor of zinc absorption, and a diet low in meat failed to provide animal protein, the principle enhancer of zinc absorption. The lack of meat also reduced the zinc content of the diet. Although whole wheat has enough zinc to meet the RDA, it doesn’t have enough zinc to overcome the effect of a high phytate, low-animal protein diet.

Dietary Patterns

High-Phytate: Whole Grains, Nuts, Seeds, and Legumes

As noted above, the phytate found in whole grains, nuts, seeds, and legumes appears to raise the zinc requirement above and beyond what is provided by these foods. While it is wise to reduce their phytate content through soaking, fermenting, or sprouting, it is not clear that this is enough. If you eat a diet rich in these foods, it is wise to consume a tier 1 food or several tier 2 foods per day on an otherwise empty stomach or with a phytate-free meal, and to move the phytate-rich foods into other meals.

Whole Foods Plant Based / Vegan / Vegetarian

Vegan and vegetarian diets have fewer top-tier options for zinc, and most of those options are rich in phytate. Low-phytate options from the top tiers include palm hearts in tier 2 and nutritional yeast and fireweed leaves in tier 3. The coconut, avocados, berries, mushrooms, seaweed, and vegetables in tiers 4 and 5 also offer low-phytate options that can provide sufficient zinc if eaten in very high volumes.

However, vegans and vegetarians may depend on legumes to meet their protein requirements, which may introduce all the problems discussed above for high-phytate diets. Vegans and vegetarians with high-phytate diets should follow the suggestions above for these diets and should consider supplementing with zinc if they experience any signs of deficiency.

High-Sugar

The higher diets are in sugar, the lower they are in zinc. This is not necessarily true for refined flour. Whole grain flours are much better sources of other minerals, such as magnesium, potassium, and manganese, when compared to refined flours. For zinc, however, refined flours make it into tier 5, and it is not clear that the extra zinc in whole grain flours is enough to compensate for their phytate content. From a strictly zinc perspective, then, refined sugar rather than refined flour should be regarded as the primary threat in desserts, baked goods, and sweetened drinks.

Replacing sugar with honey helps this somewhat, since honey only failed to hit tier 5 by a small margin, but replacing sugar with molasses (tier 5), maple syrup (tier 2), or maple sugar (tier 2) are even better options. Using sweets as “treats” instead of major dietary staples will also help.

Keto and High-Fat

When following a ketogenic or otherwise high-fat diet, it is important to realize that fat displaces zinc. Only the fats trimmed from the meats of beef, pork, veal, and lamb make it into tier 5. All other fats and oils fail to make the cut. Moreover, the fattier cuts of meat are lower in zinc than the leaner cuts. If you eat high-fat, it is important to select zinc-rich foods from the top one or two tiers, such as oysters and red meat, so that the fat does not wind up displacing lower-tier foods that you are relying on.

It’s Not All About Diet

While diet is the major factor influencing zinc status, other factors come into play as well:


Minerals Chronic diarrhea causes zinc deficiency.

Minerals Persistent vomiting can cause deficiency, especially if there is a green color in the vomit, which means you are losing bile, the fluid that circulates zinc between your liver, gall bladder, and intestines.

Minerals Heavy metal toxicity, oxidative stress, inflammation, and stress hormones all cause the body to send zinc into long-term storage. This can make you functionally deficient in zinc. Because of the involvement of stress hormones, even psychological and emotional stresses can increase your need for zinc.

Minerals Diabetes and alcoholism can cause you to lose zinc in your pee.

Minerals Crohn’s disease, celiac, and other digestive disorders can hurt your ability to absorb zinc.

Minerals Disorders that cause your red blood cells to fall apart in a process known as hemolysis, such as sickle cell disease or glucose 6-phosphate dehydrogenase deficiency, can cause the zinc in those red blood cells to be lost from the body, which can contribute to zinc deficiency.

Minerals Some people treat toxicity from heavy metals, iron, or copper with compounds that bind to these metals, known as chelators. These treatments can cause zinc deficiency.

Minerals Impaired methylation (see the lessons on vitamins B9, B12, and choline) can hurt zinc absorption.

Minerals Rare genetic defects in zinc transporters can cause deficiencies in zinc, or can cause zinc to become deficient in certain tissues.

Minerals Rare genetic defects in making hemoglobin, known as porphyrias, can cause zinc to get bound up within the body, effectively causing a deficiency.

Zinc Toxicity

Before we talk about zinc supplements, we need to know if too much can be toxic!

Rarely, zinc can cause serious toxicity. This has occurred in people who have eaten pennies and in workers who apply a rust-proof zinc coating to steel known as galvanization. In these cases, zinc toxicity can cause gastrointestinal upset, vomiting, nausea, and dizziness.

Zinc sprays applied directly to the nasal passages to beat off cold viruses have been associated with a loss of smell and taste, so these should be used with extreme caution if at all.

Taking 50 milligrams of zinc at once on an empty stomach will usually cause nausea. Smaller doses of zinc, such as 15 mg, usually do not cause nausea. When they do, taking them with a little bit of food usually does the trick.

The main concern with zinc supplementation is that it can cause copper deficiency. This is because zinc causes your body to make a storage protein that binds up extra zinc but also binds up extra copper and other minerals.

Multiple studies have shown that 50 mg/d supplemental zinc can cause symptoms of copper deficiency in adults, and the Institute of Medicine set the tolerable upper intake level for zinc at 40 mg/d for all adults over the age of 18 on this basis.

In infants, 16 mg/d supplemental zinc has caused copper deficiency, and the Institute of Medicine used this to make a bodyweight-adjusted tolerable upper intake level for everyone up through the age of 18. These are set at 4 mg/d for infants up to six months, 5 mg/d for the next six months of life, 7 mg/d for children 1-3 years old, 12 mg/d for children 4-8 years old, 23 mg/d for adolescents aged 9-13, and 34 mg/d for teenagers aged 14-18.

I consider it wise to stay within these boundaries when supplementing, unless you have a good reason to believe you need more. If you do need more, you can protect against copper deficiency by maintaining a zinc-to-copper ratio between 15-to-1 and 2-to-1. However, zinc also has the ability to induce deficiencies of other minerals, so even if you keep the zinc-to-copper ratio in check, you still shouldn’t go unnecessarily overboard with zinc supplements, and the higher you go, the more important it becomes to make sure you are getting plenty of all your other minerals.

Zinc Supplements

You should think about supplementing with zinc if you have a diet high in phytate or low in zinc-rich foods, if you suffer from any of the other conditions that contribute to zinc deficiency, or if you have any of the signs of deficiency or could benefit from any of the things we know zinc helps with.

Several studies in older adults have shown that supplementing with zinc at 45 mg/d decreases infection, inflammation, and oxidative stress, and that 80 mg/d reduces the incidence of age-related macular degeneration and protects against vision loss.

However, other studies have shown that we can only absorb about 7 mg zinc every five hours. We will generally absorb 70% of a supplement under optimal conditions, so the ideal dose to take at one time would be 10 mg, and if you wanted a high dose, you should take 10 mg 3-4 times per day, spread out as far as possible, rather than taking more at once.

There is never a reason to take 45-80 mg at once, and there is rarely a need even to take that much in one day.

For maximal absorption, zinc should be taken one of two ways:


On an empty stomach (at least 2-3 hours after your last meal, at least one hour before your next meal), with a full glass of water.
With a phytate-free meal that contains animal protein and/or is rich in sour acids from fermented foods and fruits.
To improve your zinc status, you should use capsules or tablets rather than lozenges, to make sure that you swallow the whole dose.

It is not necessary to take zinc directly with copper, but it can be convenient to get a supplement such as Jarrow Zinc Balance that has them together. What is important, however, is that if you supplement with zinc, you also have plenty of copper in your diet. This becomes especially important if you choose to supplement with more than 40 mg/d zinc.

There are several forms of zinc you could use.

Sulfate, Acetate, Gluconate, and Citrate

These are the forms that have been best studied for their ability to correct a zinc deficiency. They are all highly effective at achieving this goal.

Methionine and Glycinate

The absorbability of these forms has not been directly studied in humans, but what we know about how these compounds are absorbed suggests that these forms would be very absorbable. My personal experience using them with clients supports this.

Carnosine

Zinc carnosine is used primarily to support gastrointestinal health. Its ability to support zinc nutritional status has not been well studied, but preliminary reports suggest it does provide absorbable zinc.

Oxide

Zinc oxide is less absorbable than other well studied forms and should not be used.

Zinc Picolinate

Some studies have shown zinc picolinate can help reverse impairments in the senses of smell and taste. However, no studies have shown that it is superior to other forms for that purpose. Picolinate binds to zinc very tightly, and although zinc picolinate is absorbed, it seems the picolinate often carries the zinc right into the hair or urine without allowing it to be used by the body. Although it might make sense to experiment with zinc picolinate for the specific purpose of improving your sense of smell or taste, in general it is wise to avoid zinc picolinate and use one of the other forms whose bioavailability has been more clearly supported by research.

Killing a Cold With Zinc

High levels of zinc in the nose and throat prevents cold viruses from invading your cells. Zinc lozenges that are specially designed to fully free the zinc within your mouth so that it can migrate through your nose and throat tissue can stop a cold in its tracks if taken properly.

Currently, the only lozenges on the market that are optimized for this process are Life Extension Enhanced Zinc Lozenges. Make sure the word “enhanced” is in the title and make sure the ingredients say it has zinc acetate.

These have to be taken at the first sign of a cold, such as the very first sneeze or the very first cold-like sensation in your throat. Suck on them, don’t chew them. Take them continuously until symptoms stop, then take them every two hours until the bottle is gone. Consider taking 3-6 mg/d copper while taking them to keep these in balance.

Unfortunately these have dextrose in them, and there aren’t any sugar-free lozenges that are optimized for this effect on the market right now. So you won’t be able to use this approach if you have a strict need to avoid all sugars or to limit your carbohydrate.

Wrapping Up

Allright, let’s wrap!

Minerals Zinc deficiency causes patches of dry skin, acne, other skin problems, and frequent infection involving sore throat and diarrhea. When it gets really bad, you may lose lean body mass. When it happens early enough in life, it could impair growth and sexual development.

Minerals Zinc supplements decrease infection, inflammation, and oxidative stress, improve blood sugar, and reduce the incidence of age-related macular degeneration, a major cause of blindness in the elderly.

Minerals Zinc supports the functions of vitamins A and D, thyroid hormones, sex hormones, and stress hormones, supports blood pressure and sexual function, and protects against heavy metal toxicity.

Minerals Oysters and red meat are the best sources of zinc. Lean cuts of most meats, dark cuts of poultry meat, egg yolks (but not whites), and cheese are rich in zinc. Meat protein and whey protein, but not cheese protein, enhance zinc absorption. Sour acids from fermented foods and fruits also enhance absorption. Phytate from whole grains, nuts, and seeds hurts absorption.

MineralsAvoiding phytate-rich foods, or soaking, sprouting, or fermenting them to reduce phytate content, is important to support zinc status. However, it is also wise to consume at least one zinc-rich food per day in the context of an otherwise empty stomach or a phytate-free meal.

Minerals Vegetarians and vegans have limited options for top-tier low-phytate foods, and should consider supplementing if they find it hard to follow the recommendations above for managing phytate.

Minerals Sugar displaces zinc. Moderating sweets and using honey (ok), molasses (decent), or maple sugar (excellent) can help.

Minerals Fat displaces zinc. Focus on top-tier zinc foods if you eat a high-fat diet.

Minerals Chronic diarrhea, persistent vomiting, heavy metal toxicity, oxidative stress, inflammation, psychological or emotional stress, disorders that hurt digestion or cause hemolysis, chelation therapy, impaired methylation, alcoholism, diabetes, and rare genetic defects can all contribute to zinc deficiency.

Minerals You may benefit from a supplement if you have signs of zinc deficiency, have a dietary pattern or some other risk factor associated with deficiency, or are hoping to benefit from anything it supports.

Minerals Zinc sulfate, gluconate, acetate, and citrate are the best studied forms of zinc and work well. Zinc methionine and zinc glycinate appear to also work very well. Zinc carnosine is used for digestive issues but appears to nourish zinc status as well. Zinc oxide and picolinate should not be used.

Minerals Take zinc supplements on an empty stomach with a full glass of water, or with a phytate-free meal with meat and/or fruit. The ideal dose is 10-15 mg. If you need more, take this dose multiple times a day separated by five hours. Don’t take more than 40 mg/d, and make sure you are getting enough copper in your diet and supplements to maintain a zinc-to-copper ratio between 15-to-1 and 2-to-1.

Minerals Life Extension Enhanced Zinc Lozenges can kill a cold if used correctly at the first sign.