Zinc, as is widely known, is an essential mineral belonging to the group of trace elements. Scientists have estimated that the activity of over 300 enzymes depends on the presence of zinc. Even in its free form, i.e. as a zinc ion, this element acts as a cellular messenger; at the same time, an adequate supply of zinc in the diet supports the proper functioning of the immune system and helps protect cells from oxidative stress. Zinc is involved in DNA and protein synthesis, and thus in the processes of cell reproduction and growth. Therefore, to put it simply and using more technical language, zinc is a nutrient characterised by a broad spectrum of biological activity.
![foods rich in zinc]()
- Not just hair and immunity
- Zinc according to the EFSA
- How much zinc do we need?
- Dietary sources of zinc
- The issue of bioavailability
Not just hair and immunity
Although zinc is best known for its role in the immune system and the scalp, it is in fact an essential element for the proper functioning of all our tissues, systems, organs and body parts. The prostate gland and muscle tissue serve as instructive examples here…
A new discovery
Well, scientists have relatively recently identified a new class of cell receptors located in the cell membrane of prostate cells, also known as the prostate gland. These receptors turned out to be zinc transporters and were designated by scientists as ZIP9. As it turns out, ZIP9 receptors pump zinc into prostate cells and increase the concentration of this element within them.
In contrast, zinc acts in this situation as a secondary messenger, stimulating the production of proteins that direct the cell cycle towards programmed cell death (apoptosis). However, these observations relate to cellular mechanisms and do not provide a basis for attributing a direct effect of zinc on prostate size in humans.
What is particularly interesting is that zinc behaves quite differently in myoblasts, i.e. the precursor cells of muscle tissue. In these cells, ZIP7 receptors—similar to ZIP9—are present, though they are not bound to the cell membrane but to the endoplasmic reticulum. These receptors also pump zinc into the cell cytoplasm, where the element participates in myogenesis processes, leading to the transformation of myoblasts into muscle fibres. However, these are observations concerning cellular mechanisms and do not provide a basis for attributing to zinc the ability to regenerate muscles or increase their mass in humans.
Zinc according to the EFSA
According to the opinion of experts at the European Food Safety Authority, an adequate intake of zinc in the diet:
- contributes to the normal functioning of the immune system
- contributes to the maintenance of normal skin, hair and nails
- contributes to the protection of cells from oxidative stress
- helps maintain normal vision
- contributes to the normal metabolism of vitamin A
- helps maintain the normal metabolism of carbohydrates, fatty acids and macronutrients
- helps with normal protein and DNA synthesis
- helps maintain normal cognitive function
- helps maintain normal fertility and reproductive function
- contributes to maintaining normal testosterone levels in the blood
- helps maintain healthy bones
How much zinc do we need?
![zinc - macroelement]()
The human body’s requirement for zinc depends on gender and age, and has been established as follows:
|
Group
|
Recommended daily intake of zinc
|
|
children (7–9 years)
|
5 mg per day
|
|
boys (10–12 years)
|
8 mg per day
|
|
girls (10–12 years)
|
8 mg per day
|
|
men (over 19 years)
|
11 mg per day
|
|
women (over 19 years)
|
8 mg per day
|
|
pregnant women
|
11–12 mg per day
|
|
breastfeeding women
|
12–13 mg per day
|
However, as the rate of zinc absorption from food varies and depends on the composition of the diet, it is important to ensure an adequate intake without exceeding the tolerable upper intake level for adults. According to the EFSA, this stands at 25 mg per day.
Dietary sources of zinc
To ensure an adequate intake of zinc in your diet and to make the most of its nutritional benefits as described by EFSA experts, it is worth knowing the best dietary sources of this element. Although oysters are always cited first as a source, containing between 40 and 170 mg of zinc per 100-gram portion, the fact that this delicacy only rarely appears on our tables means that, in practice, it is not a dietary source of this element for the average person. So let’s focus on other rich sources of zinc:
|
Product
|
Zinc (mg/100 g)
|
| wheat bran |
15.6 |
| pork fat |
11.3 |
| egg yolk powder |
9.9 |
| veal liver |
8.4 |
| dried yeast |
7.9 |
| pumpkin seeds |
7.5 |
| chicken hearts |
6.7 |
| cocoa |
6.5 |
| soya meal |
5.8 |
| sunflower seeds |
5.0 |
| by |
4.8 |
| button mushrooms |
4.7 |
| beef liver |
4.5 |
| pork liver |
4.4 |
| ripened rennet cheeses |
4.0 |
| wholemeal rye flour |
3.85 |
| white beans |
3.8 |
| sausages |
3.6 |
| buckwheat groats |
3.5 |
| wholemeal wheat flour |
3.5 |
| dry hunter's sausage |
3.4 |
| powdered milk |
3.4 |
| almonds |
3.2 |
| dill |
3.2 |
| celery root |
3.2 |
| beef |
3.2 |
| horse meat |
3.15 |
| pork |
3.1 |
| turkey |
3.1 |
| oat flakes |
3.1 |
| soya |
3.1 |
| chickpeas |
2.85 |
| lamb |
2.7 |
| wholemeal bread |
2.5 |
| dark chocolate |
2.4 |
| prawns |
2.1 |
| chicken eggs |
1.8 |
The issue of bioavailability
However, it is worth noting here that whilst some plant-based foods are a richer source of zinc than certain animal-based foods, our bodies absorb this mineral more effectively from animal-based sources. Generally, zinc absorption, or its so-called bioavailability, ranges from 15 to 60%, with lower absorption rates applying to plant-based foods and higher rates to animal-based foods. The lower bioavailability of zinc from plant-based products is due to the presence of phytic acid, oxalic acid and indigestible polysaccharides, which form compounds with zinc that are difficult to absorb and insoluble in water.
Author: Sławomir Ambroziak
Sources:
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4197988/
- https://www.nature.com/articles/s41598-018-32067-0
- https://pmc.ncbi.nlm.nih.gov/articles/PMC12818375/
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