As panic is spreading over the novel coronavirus, the time is ripe for both misinformation and disinformation to thrive. In particular, sucking zinc lozenges has been heralded as a possible “silver bullet against coronavirus”. But is this really the case?

Not necessarily. The origin of this idea seems to have come from Dr. James Robb, a pathologist known for carrying out work on coronaviruses in the 1970’s. Having sent a letter privately to friends looking at the efficacy of zinc in treating coronaviruses of the past, he cautioned that this may not also be the case for COVID-19 due to a lack of scientific evidence for the virus in particular. In the spirit of misinformation however, this caution was left out of a blog post that ended up going viral.

Despite this though, Robb did suggest that sucking on zinc lozenges throughout the day could help alleviate some cold symptoms. Yet, although some studies have shown that zinc supplements may help alleviate the common cold, also caused by a coronavirus, others have shown that it may be limited in effect.

In one controlled trial for example, 50 volunteers took around 13mg of zinc acetate or a placebo every 2-3 hours for as long as they had cold symptoms. In the end, the researchers found that those taking zinc had an average cold duration of just 4.5 days, whereas for those in the placebo group, it was 8 days. While other research has shown that up to 150mg of zinc per day does not cause toxicity even though we only require an average of 15mg per day, the participants in the zinc group consumed around 80mg of the substance per day.

Meanwhile, other studies have shown that how zinc is consumed may change one’s prognosis. For example, although one study has shown that taking zinc gluconate lozenges (containing 13.3mg of zinc) tended to have lower illness time durations, another showed that those receiving zinc acetate lozenges (containing 5 or 11.5mg of zinc each) did not see any significant results.

Although exactly how zinc works is unknown, several theories exist. For example, one posits that it may prevent the virus from entering cells by binding to a protein that usually enables its entry. Another theory holds that zinc may decrease levels of cytokines in the blood, known to cause inflammation.

So what’s the bottom line? Although sucking on zinc lozenges may not prevent coronavirus, it may help ease some of its milder, cold-like symptoms. Given that taking up to 150mg of zinc over a short period of time has not been associated with any toxicity, it may be worthwhile taking the supplement regardless- especially given that low levels of zinc in the blood has otherwise been linked to cognitive impairment.



Sources: McGill, Medicine Net