Zinc – essential trace element with a healthy effect
Zinc is essential for our health. The mineral is one of the essential trace elements and plays a role in many metabolic reactions: It is involved in the function of around 300 enzymes in cell metabolism and is contained in 50 enzymes. Among other things, zinc is important for growth, sperm production and the immune system. What other effects does zinc have in the body, can zinc also be overdosed and which foods contain the trace element?
Zinc: effect in the body
Adequate zinc supply is particularly important during the growth period, i.e. in childhood and adolescence – zinc deficiency can lead to growth and development delays. Zinc is needed for cell division . It is therefore also an important trace element for the skin and connective tissue and is therefore indispensable for wound healing after injuries or operations. This is an effect that also comes into play with zinc ointment.
The body’s defense cells also need the mineral; a sufficiently high zinc intake strengthens the immune system. At the same time, it improves the structure of the mucous membrane, making it more difficult for viruses to attach and penetrate. Hence the thesis that zinc can help shorten the duration of colds. Zinc also has an antioxidant effect, i.e. counteracts free radicals.
Zinc is also required for the production of some hormones . These include insulin, thyroid and sex hormones.
Whether zinc has an anti-inflammatory effect has not yet been clarified. A US study found that the trace element had an anti-inflammatory effect in mice. To what extent these results can be generalized and transferred to humans is not yet clear.
The administration of zinc also has a positive effect on liver cirrhosis and diabetes mellitus , since zinc deficiency is often present in both cases. Of course, zinc is not a panacea, but it can improve the success of therapy.
Zinc for allergies and colds
Due to the numerous positive effects that zinc develops in the body, zinc preparations are also popular remedies for allergies and colds.
Due to its suspected anti-inflammatory properties, zinc is said to counteract inflammatory processes in the body in allergies. In addition, it is said to have a stabilizing effect on cells of the immune system that are involved in allergic reactions and thus prevent malfunctions. So far, however, there have been no comprehensive scientific studies that support this thesis.
The effect of zinc on colds, on the other hand, has been better researched. According to studies, taking zinc-containing lozenges early (within 24 hours after the onset of symptoms) can help to shorten the duration of a cold by a good quarter of the time. Higher doses are more effective here. However, medication with a high zinc dosage should only be taken for a short period of time and only after consultation with a doctor or the pharmaceutical specialist in the pharmacy in order to avoid an overdose. High-dose drugs from 25 milligrams of zinc require a prescription.
Zinkmangel
A zinc deficiency is rather rare in industrialized countries. However, some groups of people are particularly susceptible to developing a corresponding deficiency. Read below to find out what these are and what symptoms occur.
Development of zinc deficiency
A zinc deficiency can occur in three ways:
- due to an increased need (e.g. pregnant and breastfeeding women)
- through an increased loss (competitive athletes, for example, lose a lot of zinc through sweat) or
- through reduced intake
Older people who eat an inadequate or unbalanced diet are often affected by a deficiency. In addition, the zinc supply can also be critical during a diet, especially if the diet is very unbalanced during this time and/or less than 1,500 kilocalories are consumed daily over a long period of time.
In addition, diseases such as intestinal diseases or medication, for example estrogen-containing preparations or diuretics, can also cause a zinc deficiency.
People who eat a vegetarian or vegan diet are also at risk because they consume a lot of phytate (a salt of phytic acid) through their plant-based diet. This reduces the bioavailability of zinc in the intestine. This means that it forms insoluble compounds with zinc so that the body can no longer absorb part of the trace element. People who eat a lot of foods with a high phytate content should therefore pay particular attention to their zinc supply.
Foods rich in phytate include seeds, which also include grains, legumes, and nuts . However, whole grain products in particular also have a high zinc content, which is why their consumption can still contribute to a balanced zinc household.
Zinc deficiency: symptoms
Too little zinc in the body can – according to its various functions – have numerous consequences, above all:
- hair loss and brittle hair
- cracked and dry skin , skin inflammation
- brittle nails
- reduced wound healing
- growth disorders in children
- loss of appetite or diarrhea
- dry eyes
- fertility disorders in men
- weakening of the immune system
- limited performance
- Impairment of the psyche up to depression
Zinc: Overdose possible
It is usually not possible to absorb too much zinc through diet alone. Excessive intake of zinc supplements can, however, trigger an overdose of zinc, which can be dangerous for your health.
These symptoms may indicate a zinc overdose:
- nausea and vomiting
- Diarrhea
- stomach pain
- circulatory problems
- headache
In the case of a prolonged overdose, the copper metabolism in the body is negatively affected, which in turn can result in anemia and neurological problems.
For these reasons, the Federal Institute for Risk Assessment (BfR) recommends taking in a maximum of 6.5 milligrams of zinc daily through food supplements in the event of insufficient zinc intake through food .
Overall, adults should not exceed the daily dose of 25 milligrams of zinc . It is important to know that zinc from care products such as adhesive and toothpaste and especially mouthwash is also absorbed by the body. Therefore, attention should be paid to the zinc content in such products.
How much zinc a day? Daily requirements according to groups of people
Taking zinc daily with food is necessary because the body cannot store the nutrient . The German Society for Nutrition e. V. (DGE) recommends a daily intake depending on how much phytate is ingested with food. The higher the amount of phytate-rich foods, the more zinc should be consumed.
The following reference values apply:
- for men, 11 to 16 milligrams of zinc daily
- for women, 7 to 10 milligrams per day
- for lactating women and pregnant women from the fourth month of pregnancy 9 to 13 milligrams of zinc per day
Additional physical strain and stress are also said to increase the zinc requirement, so that in such situations an increased supply can make sense. In addition, athletes, the elderly, women who take estrogen preparations and people who drink alcohol regularly should ensure they have an adequate zinc intake.
foods containing zinc
Zinc can be easily ingested through food. The most zinc-rich food is by far the oyster with 22 milligrams per 100 grams.
Other foods with a lot of zinc are (per 100 grams):
- Beef (especially calf’s liver) with 8 milligrams
- Cheese, depending on the variety with 3 to 5 milligrams (higher content in mold and hard cheese)
- Eggs with 1.4 milligrams
- Oatmeal with 3.65 milligrams
- Wholemeal pasta or brown rice with 1.3 or 2.1 milligrams
- Leaf spinach with 0.81 milligrams
Zinc from animal foods is easier to digest – it covers more than half of the average daily requirement. The processing also has an influence on the zinc content of the food – the degree of grinding of grain is decisive for the zinc content of flour. The stronger the flour has been ground, i.e. the lower the proportion of whole grains in the flour, the less zinc it contains.
Powder, capsules and tablets with zinc and vitamin C
The absorption of zinc in the small intestine is reduced by phytate, tannins (in tea and coffee ) and a high intake of iron, calcium, copper or cadmium. On the other hand, the simultaneous intake of protein (e.g. the amino acids histidine and cysteine) or citric acid increases absorption.
The diverse and health-protecting metabolic effects of zinc are sensibly supplemented and supported by vitamin C – it is considered a cofactor for zinc and increases its effectiveness. Therefore, both substances are often contained together in finished preparations from the pharmacy or drugstore, such as tablets, capsules or powder.
Attention: Taking preparations with zinc can inhibit the absorption of some active ingredients in the body. These include tetracyclines, bisphosphonates, and L-thyroxine , among others .