Zinc is a mineral; it is one of the trace elements, i.e., substances that are essential to the decorous functioning of our cells but in small quantities. The body contains about 2.5 g of which 60% are present in muscle and 30% in the bones. The remaining 10% is distributed in the skin, eyes, kidneys, pancreas, adrenal glands, and the prostate glands.
Zinc plays a major role in our growth, the immune, neurological and reproductive functions. It is necessary to more than a hundred of vital enzymatic processes in the body (300 as estimated by experts). It participates in the synthesis of DNA, RNA, and proteins, immune processes and wound healing, reproduction and growth.
Recommended daily intake of zinc
Zinc deficiency causes many health problems, especially reduction of the physical and intellectual development of children, increased susceptibility to infections, fetal malformations. Zinc supplementation can cure faster common infections (colds, for example). The prescribed daily intake of Zinc is 15 mg per day for an adult. However, this intake should be adapted based on your age and your activity.
People at risk of deficiency Zinc are particularly children, pregnant and lactating women, people malnourished (e.g. anorexia), elderly, strict vegetarians people. An estimated 82% of pregnant women in the world have inadequate zinc intake. The amount of zinc recommended in the diet in the United States is:
|Age||Intake (in milligrams)|
|Infants (0-1 years)||5|
|Children (1-3 years)||10|
|Sportsmen or acne||40|
In the case of large excess, zinc can be toxic. Zinc can become toxic from 150 to 450 mg/day.
Do you know that!
The result of excessive consumption of long-term zinc (e.g., 60 mg / day) is a deficiency of copper? At high doses, it prevents copper absorption by the body and conversely, a long copper cure significantly hampers zinc absorption and causes a deficit in zinc. The body may also be faced with a zinc deficiency if there is a significant supplementation of iron (more than 25mg). An excess zinc in the body can lead to a reduction in HDL (good cholesterol).
Health benefits of zinc
- Reduces oxidative stress. Oxidative stress plays a role in aging. Two clinical trials, double-blind, placebo measured the effect of zinc supplementation in people over 50 years old in good health. Taking 15 mg or 30 mg of zinc for six months had no effect on markers of oxidative stress (387 subjects) 23, but a 45 mg dose for one year had a positive effect on these markers (50 subjects)
- Zinc is essential for the formation of sperm in men. Zinc deficiency in men can lead to impotence. It was found that zinc supplements help stimulate the production of sperm and eliminate sexual dysfunction in men.
- Zinc has recognized effects against acne: it not only contributes to fighting against the bacteria that cause pimples but also limit inflammation and therefore reduce redness.
- Zinc is useful for maintaining healthy skin, hair, and nails: This trace mineral that promotes healing is effective against many skin problems: psoriasis, ulcers, skin infections. It is an ally of choice for beautiful skin but also beautiful hair and healthy nails (deficiency zinc can result in hair loss and brittle nails).
- Promotes enzyme function: Zinc is essential in activating the function of many enzymes in the body that play a major role in various metabolic activities of the body. Moreover, it plays a vital role in wound healing, the construction of the body’s immune system, and is required for DNA synthesis.
- Zinc deficiency can lead to partial loss of smell and taste. The protein responsible for these functions works suitably in the presence of sufficient amount of zinc in the blood.
- Zinc supplements are prescribed by doctors to treat patients with digestive disorders such as Crohn’s disease, sprue, and short bowel syndrome. Patients who have undergone gastrointestinal surgery are often prescribed with zinc vitamin supplements to boost overall immunity and for a quick recovery.
- Some studies have found that zinc is particularly beneficial for the treatment of influenza zinc. It has been proven that this metal has a preventive and curative effect against colds provided its taken at early stages. A cure can reduce the duration of colds and flu symptoms.
- Zinc plays a vital role in child development. Among its many functions, zinc promotes normal growth and child development during pregnancy and is an essential element in the development of sperm, ovulation, and fertilization. Children, who lack zinc in their diet may be affected by dwarfism. Sexual development of these children.
- Zinc deficiency in pregnant women can slow fetal growth. Nursing mothers should also be provided with zinc supplements to offset the loss of cellular zinc during lactation.
Friends and enemies of zinc
- Zinc absorption sees a decrease in certain conditions or the presence of other elements: Calcium, phosphorus, and copper in large quantities: they compete for the same routes to cross the intestinal wall.
- Food processing, such as canning or preserves, and refining, for cereals: they decrease the levels of zinc in food
- Too sweet diet: it increases the zinc requirements.
- Alcohol abuse: it increases the urinary excretion of zinc.
- Smoking: it increases the antioxidant requirements and draws zinc reserves.
- A high content of phytic acid content in the seeds of cereals and pulses: it reduces zinc absorption. The phytic acid can reduce by cooking or seed germination, or with yeast in whole meal bread.
- Vitamin B6: it promotes the intestinal absorption
- Cysteine: it is useful for the synthesis of molecules that carry zinc.
- Histidine: it improves the absorption.
Natural sources of Zinc
Oysters: The best source of zinc
By providing at least 20 mg zinc per 100 g, this food is definitely the best source of zinc.Oysters can be eaten raw or steamed since this preserves the trace element. They can be eaten once or twice a month.
Veal liver is also an excellent source of zinc. It provides 9 mg of the trace element per 100 g consumed.It can be steamed, grilled or cooked in a pan with herbs. You can eat veal liver once a week or every two weeks.
With 6 mg per 100g consumed, beef is a renowned source of zinc. For efficiency, this trace element has to be linked to proteins, which is beneficial and its present in beef.
How to eat it: prefer the less oily parts such as the rump or shank. Red meat can be on a menu once or twice a week without exceeding 500g total. One study, in particular, demonstrated the link between excessive consumption of red meat and colon cancer.
Lentils, beans, and peas
Lentils and beans are rich in zinc. They contain 5.50 mg per 100g. Split peas contain 3 mg per 100g. By eating these foods, vegetarians can avoid being deficient in zinc. Vegetables are an excellent substitute for meat. However, be aware that they contain phytic acid which inhibits the absorption of zinc and makes the least efficient assimilation. Thus, zinc from vegetable assimilates less than zinc from the animals.
How to eat them: in salads or warmed, the lenses can be consumed several times a week. Also, they contain little calories and contain fiber.
The wholemeal bread provides approximately 5 mg of zinc per 100g. But again, as this zinc is of vegetable origin, it is a little less well absorbed by the body.
How to consume: prefer natural sourdough bread yeast to the base. The longer fermentation time reduces phytic acid (which inhibits zinc absorption)
In addition to its protein and vitamins, an egg yolk contains up to 4 mg per 100g of zinc. For your nutritional intake, the egg is a good substitute for meat, And contrary to popular belief, it does not promote cholesterol.
How to consume: poached or boiled, you can eat two eggs three times a week.
You can stock up on zinc in the morning by eating a bowl of oatmeal or crunchy soy beans. Both contain 3 mg of zinc per 100 g. Again, phytic acid reduces the absorption of trace element, but the remaining amount is sufficient.
How to eat them: prefer cereals sold in “raw” form.
In herring, zinc content goes up to 2 mg/100g. The advantage of herring is that it is a small fish with less toxic heavy metals. Moreover, it is a fish rich in omega 3.
How to consume: The fish can be eaten twice a week.
Flour and sesame tahini (sesame butter)
Sesame-based food products contain about 10 mg of zinc per 100 g serving (70% RDA). You can use the sesame flour to replace wheat flour in the preparation of cakes and bread. Tahini is usually found in hummus; a chickpea purée often served in the kitchen of the Middle East. Tahini provides 4.6 mg of the mineral per 100 g serving (31% of RDA). 100 g full sesame seeds contain 7.8 mg of this trace element (52% RDA in micronutrient).
Pumpkin seeds and roasted squash
It is a popular food in the Middle East and East Asia. The seeds of pumpkins and squash provide about 10 mg of zinc per 100 g serving (70% RDA).
You can cook the pumpkin seeds in an oven and grill the squash. These seeds are usually eaten by breaking the outer shell and eating the inner seeds.
Dried watermelon seeds
Like seeds of pumpkins seeds and squash, watermelon seeds are good sources of zinc. Dried watermelon seeds provide 10 mg of zinc per 100 g serving (about 70% of RDA for this mineral).
Watermelon seeds can be eaten raw.
These foods are a good source of zinc but watch your portions. 100 grams of oil roasted peanuts provide 6.6 mg of this trace element (44% RDA). The same amount of oil-roasted peanuts will bring less than half (about 3.3 mg per 100 grams, or 22% of RDA of this mineral).
Vegans: do they have enough zinc?
While zinc from plants is known to be less well absorbed, vegans do not seem more affected by zinc deficiency than others. According to a recent study, vegans have their zinc levels slightly below the average in their plasma. No study has yet verified the zinc levels in cells. It is important to pay particular attention to zinc intake for babies and infants.
Symptoms of zinc deficiency
The populations of the third world or developing countries are most prone to the risk of zinc deficiency because of food problems. A deficiency in this trace element results in fatigue, growth retardation or even repeated illnesses.
The symptoms of zinc deficiency are:
- Decreased immunity and therefore repeated infections.
- Loss of taste and smell, eye disorders
- Growth failure in children
- Learning Disabilities
- Loss of appetite
- Weight loss
- Dry skin, hair loss, dandruff, brittle nails and striated
- Delays in sexual maturation
- Skin problems, delayed wound healing
- Impotence and male infertility
Did you know?
Maintenance chores of our bodies are not made by fairy finger proteins. But by proteins called “zinc finger”! Zinc plays a structural role required for stability of these proteins, which fulfill a variety of functions in diverse cellular processes.
Groups at Risk of Zinc Inadequacy
- Growing people: fetus, children, adolescents, pregnant and lactating women, persons injured during healing
- Stressed people: individuals suffering psychological or physical stress (including top athletes)
- People whose immune defenses are weakened: this group includes the sick especially persons with chronic diseases (including AIDS)
- People suffering from kidney disorders, digestive disorders (Crohn’s disease), alcoholism, or diabetes
- People rich in phytate feed or relatively low in zinc: vegetarians, people who consume little meat or fish, people consuming a lot of unfermented whole grains, and the elderly.
- People who sweat a lot: under normal circumstances, about 0.5 mg of zinc daily can be lost through sweat.
- Men: Their daily needs are higher than those of women because their reproductive system requires zinc. Zinc is also a key ingredient in dietary supplements for increasing male fertility.
Adverse side effects of zinc and precautions
Zinc intake may be associated with the occurrence of gastrointestinal disturbances, usually mild and temporary such as:
- Stomach upset
- Abdominal cramps
Copper deficiency due to zinc
As mentioned earlier, excessive intake of zinc over the long term can lead to copper deficiency because it prevents its absorption by the body. Copper deficiency results in anemia, bone disorders such as osteoporosis, etc.
Reduction of good cholesterol
Studies have shown that zinc supplementation could reduce the high-density lipoprotein (HDL), the “good cholesterol,” thus contributing to increase the risk of cardiovascular disease.
Zinc and prostate cancer
The links between zinc and prostate cancer are quite ambiguous, but some research shed light on the issue: One study showed that men who took supplements containing more than 100 mg of zinc daily for 15 years were exposed to twice the risk of developing prostate cancer than the rest of the population.
Other research highlights the interest of the zinc supplement intake in patients with prostate cancer. An article published in 2011 showed that mortality from this cancer was lower in men who received 16-20 mg of zinc per day, compared to those whose daily contributions were limited to 9-13 mg.
In case of massive zinc intake is intoxication, resulting in different symptoms:
- Loss of balance, difficulty walking
- Numb limbs
- Nausea, vomiting, diarrhea
- Joint pain, fever
- Metallic taste in the mouth
Do not exceed the prescribed dosage for zinc.
Tolerable Upper Intake Level (UL), which correspond to the daily amount of zinc should not be exceeded. The daily intake for each group should be observed to avoid the risk of health complications.
2 Recipes that are high in Zinc
- Prep time: 10 minutes.
- Cooking time: 8 minutes
- Servings: 5
- 24 oysters
- 30 g of butter
- 1 tablespoon Coffee
- 15 cl of milk breadcrumbs
- 3 sprigs parsley dish
- Open the oysters, remove the flesh from shells by getting the juice and filter it through a fine sieve.
- In a saucepan, cook the oysters in their water for 3 minutes, then drain keeping the cooking water.
- Melt the butter in another pan, sprinkle with flour and pour the cooking water and milk while whisking until you get a smooth butter. Add salt only, pepper and a little nutmeg.
- Turn on the oven grill. Divide the empty shells on a baking sheet, put the oysters in their shell, pour the sauce over paprika sprinkle with bread crumbs, place a small knob of butter on each oyster, sprinkle some parsley leaves and go under the grill 4-5 mins.
Scrambled eggs with salmon
- Prep time: 5 minutes.
- Cooking time: 10 minutes
- Servings: 4
- 8 eggs
- 100g slices salmon, smoked
- 25 g of butter
- 1 tablespoon cream chives chopped
- Break 8 eggs in a saucepan and add salt, pepper and 25g butter into slices.
- Place over medium heat and cook, stirring constantly with a spatula, until the eggs are just set. Remove from heat and add 1 tbsp. of cream.
- Divide into 4 bowls and garnish 100g slices of smoked salmon and chopped chives.