Generality
Zinc is a metallic mineral essential for human life and health; thanks to its innumerable properties, it is widely used in drugs, food supplements, deodorants, cosmetics, personal hygiene products etc.
It is involved in a very long series of physiological processes and is contained, in a relatively abundant manner, in certain foods; also to enjoy its therapeutic properties, it may sometimes be advisable to increase its nutritional intake with food supplements.
On the other hand, the correlations between zinc and health do not stop at the nutritional role. It is in fact responsible for a long series of reactions and interactions with the organism that can be considered "therapeutic".
Zinc is mainly used in oxidized form: zinc oxide (ZnO). Probably less effective, but still present in various formulas, is zinc sulphate (ZnSO4). Forms of zinc acetate [(CH3COO) 2Zn] and zinc gluconate (C12H22O14Zn) are also widespread.
In recent years, technological progress has also enabled the development of a further pharmaceutical type reduced to nano particles, extremely effective especially in the formulation of topical creams and ointments. It has the same applications as the traditional one but, apparently, is more effective.
Property
Properties of zinc
Zinc has numerous properties that can be used to improve human health. This mineral can exercise its effectiveness differently and in different applications. This depends on whether it is made absorbable or not or whether it is taken orally or applied topically. The properties of zinc, although not all confirmed by scientific literature, are:
- Topical use - creams, ointments, ointments and sprays:
- Antibacterial
- Antiviral; note : zinc-based nasal sprays have been withdrawn from the market
- Antipruritic - in creams, ointments, baby powder, shampoo etc.
- Solar filter
- Estimate muscle injuries
- Deodorant
- Internal use - zinc supplements, generally formulated in tablets:
- Antioxidant
- Antiviral - against rhinovirus cold
- antidiarrheal
- Antidepressant
- Partly preventive against age-related macular degeneration
- Remedy for enteropathic acrodermatitis
- Reduces the symptoms of infectious gastroenteritis
- It is possible that you mask drugs in urine.
Topical Use
Antibacterial and deodorant properties
Zinc oxide has deodorising and antibacterial properties and for this reason it is added to materials and fabrics such as cotton, rubber, and products for oral hygiene and food packaging. Zinc chelate is used in toothpastes and mouthwashes as a preventive agent from halitosis.
The antibacterial action, better in particulate matter, is not exclusive to ZnO and is also shared by other materials such as silver. This greater efficacy is induced by the increased surface area of the fine particles compared to the large ones.
Zinc nanoparticles against bacteria
The nanoparticles of zinc oxide, which have an average size between 20 nm and 45 nm, can improve the antibacterial activity of ciprofloxacin - a fluoroquinolone drug - in particular against Staphylococcus aureus and Escherichia coli ; note : the observation was made only in vitro.
The strengthening effect of this nanomaterial depends mainly on the concentration compared to all the test strains. The mechanism of action could be twofold:
- First of all, the zinc oxide nanoparticles could interfere with the NorA protein, which is developed by the bacteria to confer greater resistance, and serves to mediate the efflux of hydrophilic fluoroquinolones from the cell
- Second, the zinc oxide nanoparticles could interfere with the Omf protein, which is responsible for the permeation of the quinolone antibiotics inside the cell.
Anti-itching properties
Zinc oxide is widely used to treat various skin conditions including dermatitis, itching from eczema, diaper rash and acne. It is used in products such as: baby powder, protective creams for the treatment of diaper dermatitis, calamine-based creams against itching - zinc oxide (ZnO), mixed with about 0.5% of iron oxide ( III) (Fe2O3) - anti-dandruff shampoo - zinc pyrithione - and antiseptic ointments.
Hypothetical preventive propitiousness from injuries in taping
It is also an ingredient of the "zinc oxide tape" - zinc oxide tape - used by athletes as a bandage to prevent soft tissue damage during workouts.
Solar filter properties
Zinc oxide can be used in ointments, creams and lotions, it is useful to protect the skin from sunburn and damage caused by ultraviolet light - see sunscreen.
It is the largest UVA and UVB absorber filter approved as a sunscreen by the US "Food and Drug Administration" (FDA) and is completely photostable. Used as an ingredient in sunscreens, zinc oxide blocks UVA (320-400 nm) and UVB (280-320 nm) of ultraviolet light. Like titanium dioxide, ZnO is considered non-irritating, non-allergenic and non-comedogenic.
Zinc nanoparticles against sunburn
Many sunscreens use zinc oxide and titanium dioxide nanoparticles to avoid the "white" effect of the cream.
Internal use
Zinc as a food supplement or drug
Most multi-saline and vitamin food supplements taken daily, as a single tablet, contain nutritious zinc in the form of zinc oxide, zinc acetate or zinc gluconate.
There are also many pharmacological remedies based on zinc, always for internal use, which base their mechanism of action on the effectiveness of this mineral.
Antioxidant property
Zinc is considered a powerful antioxidant and dietary supplementation is recommended to counteract the action of free radicals. However, it is an inert redox that performs its antioxidant function only indirectly. However, it is undeniable that, especially in the case of incorrect diet or malabsorption - primary or secondary - zinc-based supplements can improve health.
Partial antidepressant properties
Zinc deficiency has been shown to be associated with major depressive disorder (MDD) and, in some cases, zinc-based products may be a relatively effective adjuvant treatment.
Antidiarrheal properties
Zinc administration is a simple, cost-effective and effective solution for treating episodes of diarrhea in children in developing countries. In the past it was thought necessary to increase zinc intake, due to diarrhea, only to compensate for fecal losses. On the other hand, recent studies show that zinc supplementation - a treatment cycle of 10 to 14 days - can reduce the duration and severity of episodes, and also contribute to preventing them up to three months.
Therapeutic properties for colds
Products based on zinc - zinc acetate or zinc gluconate - are frequently used for the treatment of the common cold. The hypothetical mechanisms of action by which zinc reduces the severity and / or duration of cold symptoms are: suppression of nasal inflammation, direct inhibition of rhinovirus receptor binding and rhinoviral replication in the nasal mucosa.
For more information, see also: Zinc and Cold.
Possible preventive property of Senile Macular Degeneration (AMD or ARMD)
A review by Cochrane showed that taking zinc-based products is less likely to progress to age-related macular degeneration. But be careful, this is not a cure and even less a preventive method in all respects. The study simply found a statistical correlation showing a general risk reduction for AMD / ARMD related to food supplementation with zinc.
deepening
Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a pathological and worsening medical condition that can induce blurred or absent vision in the center of the visual field.
Therapeutic properties against Enteropathic Acrodermatitis
The increase in zinc intake is an effective remedy for the complications of Enteropathic Acrodermatitis, a genetic disease that affects the absorption of zinc. Note : In the past, Enteropathic Acrodermatitis was lethal since the neonatal age.
Enteropathic Acrodermatitis is an autosomal recessive metabolic pathology that affects the absorption of zinc in the intestinal mucosa. It is characterized by: inflammation of the skin (dermatitis) around the body orifices (periorifial), on the extremities of the fingers and toes (acral), hair loss (alopecia) and diarrhea. It may be related to a secondary zinc deficiency.
Therapeutic properties for gastroenteritis
Zinc supplementation significantly attenuates the symptoms of infectious gastroenteritis, probably due to the direct antimicrobial action exerted by the zinc ions in the gastrointestinal tract, or by the release of zinc (post-absorption) by the immune cells - all granulocytes secrete zinc - or both.
Note : this is a different effect than the anti-diarrheal one mentioned above.
Possibility to conceal drugs in the urine
In 2011, some researchers reported that adding large amounts of zinc to a urine sample is able to mask the detection of drug traces. However, scientists have not verified whether the consumption of an oral zinc food supplement can have the same effect.
Food Additive
Zinc food additive
It is important to remember that zinc does not promote human health only as a pharmacological remedy, but also as a food additive or nutritional reinforcement.
Zinc oxide - or zinc sulfate - is added to many food products as a reinforcement, such as breakfast cereals. Note : although not used as a reinforcing ingredient, it is common to find trace zinc oxide in packaged foods.
Zinc and food contamination
Zinc oxide was associated with dioxin contamination which affected pig meat exports in the 2008 Chilean pig crisis. Contamination resulted from polluted feed used as fodder.
Dentistry
Zinc oxide in dentistry
The zinc oxide (ZnO) mixed with eugenol forms a ligand and gives rise to zinc oxide eugenol (ZOE), used in conservative and prosthetic dentistry.
Side effects
Side effects of zinc for internal use
The most common and least serious side effects of zinc-based products include bad taste and nausea. Excessive consumption of zinc can cause ataxia, lethargy and copper deficiency.
Side effects of zinc for topical use
Intranasal use of zinc-based sprays has been associated with loss of smell and, consequently, in June 2009, the US Food and Drug Administration (USFDA) suggested that consumers stop this kind of therapy.
There are no side effects of the use of zinc in topical products such as: cream, gel, ointment etc.
Initially it was feared that the use of zinc oxide in nanoparticles could favor skin absorption. A study published in 2010 found that only a 0.23 - 1.31% (average 0.42%) of zinc in venous blood could come from the nanoparticles of the applied products for 5 days; only a few traces have been detected in urine samples. Furthermore, a complete review in 2011 did not identify any evidence of systemic absorption.
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