You don't need to stick it out until your cold goes away. It's time to unleash the power of zinc lozenges, says Professor Graeme Close.
🕒 6 min read
Colds can result in lost training days and impaired match day performance, so anything that can speed up recovery would be very welcome. Research shows that zinc acetate lozenges at the right dose can help you to kick that cold sooner.
What is a common cold?
The average UK adult suffers from 2-4 colds each year, with some people, such as asthmatics, having considerably more. The symptoms of a cold usually clear up within 2 weeks, although in some cases can last longer. This means that over the course of a lifetime we spend approximately 2.5 years battling the symptoms of one of the over 200 viruses that can cause a cold.
In simple terms a cold is mild viral infection of the nose, throat, sinuses and upper airways. Symptoms can be mild including a runny nose, sore throat, sneezing and coughing although with more extreme colds symptoms can also include fever, headache and muscle soreness.
The current advice is to rest, drink plenty of fluids, if necessary take painkillers (such as paracetamol and ibuprofen) and decongestant sprays (it must be pointed out that any competing athlete should check all medication on Global Dro prior to taking it to ensure it is not prohibited in their sport). However, the current advice could now change given the evidence regarding Zinc acetate lozenges.
Zinc and the immune system – how zinc lozenges help
For many years, it is has been known that zinc deficiency compromises the immune system, increasing the risk of infections. In some developing countries where zinc deficiencies are common, supplementation with zinc can reduce the risk of colds and even pneumonia. However, in developed countries like the UK giving supplemental zinc in the region of 15-20mg per day has consistently been shown to have no effects on illness in non-deficient people
This observation almost ended interest in using zinc to prevent colds. However, interest was re-ignited with the observation that a 3-year-old girl with Leukemia who dissolved a therapeutic dose of zinc in her mouth rather than swallowing it was able to completely get rid of a cold within hours of taking the dose.1
This created the hypothesis that zinc dissolved in the mouth could be helped through local effects in the pharyngeal region (the part of the mouth behind the throat and nasal cavity) and this has been further substantiated given that similar doses of zinc swallowed in syrups are nowhere near as effective.
Zinc acetate – why this specific form and at what dose?
Following the early observation from Eby and colleagues, there followed a series of subsequent trials with differing results. The variation may have been a result of the specific composition of the lozenge. Zinc lozenges are chelated with differing salts, such as zinc citrate or zinc acetate.
It appears that problems arise when zinc binds tightly to its salt (such as in zinc citrate), resulting in reduced free zinc ions available to assist in the pharyngeal region. Zinc acetate, however, does not chemically bind to zinc, and so this specific form of zinc appears to be the most effective at alleviating symptoms of the common cold.
In a recent meta-analysis (a study that combines all appropriate studies into one big one to make a much stronger study) has suggested that in the correct form and at the correct dose, supplementation of zinc lozenges can reduce cold duration by approximately 44%. This is the equivalent over a lifetime of 401 days of reduced symptoms - a huge amount of time.
The dose seemed to be particularly important. In the meta-analysis there were no benefits if the total daily dose of elemental zinc was less than 75mg, whereas clear benefits were observed in the studies that provided greater than 75mg of elemental zinc per day.
It must be stressed that the authors did not suggest that 75mg is a precise number, and further research is now warranted to better define the optimum therapeutic dose.
Zinc Defence Lozenges
Take at the first sign of cold and flu
- Throat lozenges with zinc to defend your immune health
- Coats the membranes of nose and throat when taken at the first sign of cold and flu
Zinc acetate versus elemental zinc
There is some confusion with regards to the total amount of zinc in supplements. Given that zinc supplements, such as zinc acetate, have zinc chelated to a salt, it is important to understand the total dose of elemental zinc in the product – elemental zinc is the active ingredient. Zinc acetate is simply zinc ions combined with acetic acid.
Zinc acetate contains approximately 30% elemental zinc, so to achieve 10 mg of elemental zinc approximately 34 mg of zinc acetate is required. When calculating how much zinc you need, it is important to base this on the elemental zinc not the zinc acetate. This is why every zinc supplement should show you the elemental zinc as well as the total zinc acetate on the packaging.
Safety of high dose zinc
The educated reader may now be wondering why, if the current RDA for elemental zinc is only 9.5 mg per day for males and 7 mg for females, I am suggesting 90mg per day. They would be correct to ask. Long-term high-dose zinc supplementation can be toxic and result in copper deficiencies, which can lead to anaemia and weakening of the skeleton.
However, these are long-term studies, whereas this article has looked at targeted short-term (maximum 1 week) supplementation to alleviate the symptoms of a cold.
It should be stressed that this dose of zinc SHOULD NOT be taken for more than one week. Recent trials looking at zinc acetate specifically have shown no adverse effects giving 92mg over a short period of time, and in the slightly longer term there were no adverse effects on copper following 6 weeks of supplementation. There is therefore no scientific basis to suggest that 1 week of high-dose (around 90mg zinc) will have detrimental health effects.2
Other side-effects reported with high-dose supplementation are constipation and a bad taste in the mouth. If the bad taste is a problem the advice is simply to stop taking the supplement. It does however appear that the bad taste is dependent upon the composition of the lozenge rather than the zinc itself.
Conclusion and recommendations
At some point in the year the chances are we are going to get a cold, but now we may be able to fight back. Emerging research suggests that slowly dissolving zinc acetate regularly throughout the day, achieving a daily dose that provides more than 75mg of elemental zinc, could reduce the duration of the cold by 44%.
This reduction could be the difference between being able to compete at your maximum at the weekend or going into competition compromised. This is great news for everyone. At last, we have a simple, effective and proven strategy we can use to speed up recovery from the common cold.