Hieronymus Gaubius, a German physician, introduced zinc to the west in 1771.
It is still available in pharmacies more than 200 years after its discovery. It is even thought to be one of the few things that can help with common cold symptoms. Or does it?
There is little evidence for zinc supplement use. The results of studies have been mixed and the dosage, formulation, and length prescriptions have not been properly investigated.
A meta-analysis of 28 random controlled trials has confirmed the idea that zinc supplementation could reduce symptoms and prolong the life expectancy of viral respiratory infections like the common cold and flu.
"It is often believed that zinc's role is limited to people who are deficient in zinc; our findings really challenge that notion," Jennifer Hunter, an integrative medicine doctor at Western Sydney University in Australia.
"The risk of developing clinical illness was reduced by very low doses of zinc nasal spray in the two large Chinese trials. People who are zinc deficient were not included in the two smaller US trials that examined the preventive effects oral zinc.
"All other trials that tested zinc for the treatment of the common cold were done in populations with very low zinc levels."
The analysis showed that zinc taken as a preventative measure had a 28% lower chance of milder symptoms and an 87% lower risk for moderately severe symptoms.
Zinc can be used to treat symptoms that haven't resolved. Zinc usually reduced the severity of symptoms by about two days.
This is a very small effect considering that the symptoms are still severe. The zinc won't prevent a patient from getting sick with a cold virus if they are intentionally infected.
Although this analysis is a significant step forward, the researchers cautioned that not all studies were comparable, they did not compare different dosages and there could have been bias in reporting symptoms. When conducting meta-analyses, it is important to remember that the results will only be as reliable and accurate as the input.
These findings, however, are not able to tell us much about the effectiveness of zinc in fighting viral infections like the common cold.
Gaubius's'secret drug' was being sold to severe convulsions by alchemists before the 18th century. Gaubius discovered that the powder was zinc oxide when he got it.
Zinc was once used to treat epilepsy in the 19th century. However, by the 20th Century, it had lost its popularity and been forgotten.
Zinc was first discovered as a possible treatment for natural zinc deficiency and Wilson's disease (rare inherited disorder that causes copper buildup in vital organs). It was not until the 1960s when it came back to prominence. This neurological disorder has been treated with zinc as an anti-copper agent.
However, the potential of viral infection fighting is still not fully realized.
However, oral zinc is recommended for people with lower respiratory infections. The recent COVID-19 pandemic brought this potential back to light.
Some healthcare professionals have begun to use zinc for COVID-19 treatment despite the lack of results from some randomized control trials.
If the patient is properly screened and the dosage is not too high, the risks are minimal. There are very few serious side effects to taking this supplement unless there is a condition that allows bodily zinc into the brain.
Certain dosages of zinc may have side effects that are not serious, such as nausea, or, as with too much zinc nasal sprays, loss of smell. We don't know the best way to get zinc.
Hunter states that there is still a lot of uncertainty regarding the clinical efficacy and dosages of various zinc formulations.
"At this time, there isn't enough research that can compare a zinc nasal spray with a gel nasal spray or lozenge with oral zinc. The majority of trials used zinc gluconate and zinc acetate formulations. However, this doesn't necessarily mean that other zinc compounds have less effectiveness.
More research is needed. Gaubius would be a perfect fit.
The study was published by BMJ Open.
