The essential trace element zinc
Zinc is an essential trace element that humans cannot produce themselves and must therefore obtain from food. As it cannot be stored in the body, it must be supplied either through food or supplements in order to avoid a zinc deficiency and the associated symptoms and illnesses. In the human body, this mineral is required for numerous metabolic processes, cell division, the immune system, digestion, insulin storage, haematopoiesis and sperm production. It is also responsible for taste and odour perception!
What exactly is zinc anyway?
After iron, zinc is the second most common trace element in the human body. It is necessary for the action of over 300 enzymes, as well as for fat, sugar and protein metabolism. As the body cannot produce it on its own, it is referred to as an essential trace element.
What is the effect of zinc in the human body?
Zinc plays a major role in the human immune system and in energy production. It is heavily involved in metabolism, promotes muscle development and wound healing and also strengthens the body against hair loss. It is responsible for the formation of new tissue, beautifies the skin and strengthens hair and nails. The mineral promotes wound healing and has an anti-inflammatory effect. It contributes to the stabilisation of cells and their division, growth, blood clotting, thyroid function, vision and promotes the sense of taste and smell [3].
How does a zinc deficiency affect the psyche?
In embryos, a zinc deficiency can lead to developmental disorders. In children, one symptom of this can be learning difficulties and lack of concentration. In general, a deficiency of this trace element in the body can also be the cause of depressive symptoms. Zinc ions help to regulate nerve signals at the synapses. This enables the body's commands and reflexes to be processed correctly in the brain [2]. If there is a zinc deficiency in the brain, there is a high risk of depression, aggression or anxiety.
Symptoms of zinc deficiency
Low zinc levels can put a strain on health and cause illness. Zinc deficiency can be caused by an unbalanced diet.
Some signs of a deficiency are:
- Frequent colds
- Depression and mood swings
- Gastrointestinal complaints
- Fatigue
- Lack of concentration, learning difficulties, lack of drive
- impaired wound healing
- inflammation of the skin
- brittle nails
- hair loss
- impairment of libido
How should the zinc level in the body be measured?
It can be easy to overlook the signs of zinc deficiency. However, if you have noticed one or more symptoms of a zinc deficiency in your body and suspect that the cause is a dietary deficiency, you can easily recognise how high your zinc level is by taking a blood test. The measurement should always be carried out in whole blood (not in serum or plasma), as the trace element is mainly found in the cells. If the result indicates a zinc deficiency in your body, the doctor will recognise whether the deficiency can be compensated for by a healthy diet with more zinc-rich foods or whether the daily zinc requirement should be supplemented with zinc supplements.
How can the bioavailability of zinc be increased?
There are zinc supplements on the market on an inorganic and organic basis, as well as bound to amino acids. In principle, the body can utilise the trace element better if it is organic or in combination with amino acids. In the case of food, the intake of L-lysine (amino acid) or quercetin (plant substance) can increase the absorption of the trace element from the intestine and promote health.
Some of the zinc compounds currently on offer are:
- Zinc oxide (inorganic form, not well utilisable by the body)
- Zinc sulphate (poor quality and can lead to side effects)
- Zinc gluconate (bound to gluconic acid, well utilisable)
- Zinc citrate (organic form of zinc, well utilisable)
- Zinc bisglycinate (bound to the amino acid glycine and very well utilisable [4], stomach-friendly)
When and how should you take zinc?
Even with a balanced and healthy diet, the daily requirement of this trace element cannot always be met. To avoid a zinc deficiency, daily supplementation should be taken if symptoms are suspected. The German Nutrition Society assumes a requirement of around 11-16 mg per day for men and around 7-10 mg for women [1].
The best time to take zinc is in the evening before going to bed with plenty of water.
Who is at high risk of zinc deficiency?
An increased requirement for competitive athletes, those on a plant-based diet, with a weakened immune system and gastrointestinal infections (e.g. diarrhoea). Pregnant women and women who are breastfeeding also have an increased need for zinc.
Which foods contain zinc?
Good sources of zinc are: Oysters, beef, seafood, sea fish, cheese and other dairy products, eggs and wholemeal products. Zinc from animal foods can be better utilised by the body than that from plant sources. Therefore, vegetarians / vegans should pay particular attention to a sufficient intake!
Tips for vegetarians / vegans
Since vegetarians / vegans consume an increased amount of phytate due to their plant-based diet, which prevents zinc absorption, they should pay attention to a sufficient zinc intake! However, there are simple ways to achieve the recommended zinc intake. Soaking pulses, cereals and oilseeds in water overnight activates the germination process. This activates the enzyme phytase, which can break down phytic acid so that it can no longer bind the zinc. Due to the low phytate intake, a higher bioavailability can be obtained from plant-based foods [1].
Sources
[1] https://www.zentrum-der-gesundheit.de/ernaehrung/mineralstoffe-spurenelemente/weitere-mineralstoffe-spurenelemente/zink
[2] https://www.mpg.de/521999/zink-am-dimmer-des-nervensyste
[3] https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:136:0001:0040:DE:PDF
[4] https://www.naturalie.de/zinkformen-unterschiede/