Will taking zinc for colds make it go away 3-times faster?
Hello everyone,
Colds are a nuisance almost all of us experience several times a year - particularly in the colder months. We previously addressed whether Vitamin C can help fight colds, today we investigate another nutrient which has been in the spotlight - zinc. To find out more about the potential health benefits of zinc we asked 5 experts in alternative medicine, nutrition, biology and epidemiology, ‘Will taking zinc for colds make it go away 3-times faster?’
EXPERT CONSENSUS
Will taking zinc for colds make it go away 3-times faster?
4 out of 5 experts say ‘likely’
What is Zinc?
Zinc, iron, cobalt and manganese are metals and essential trace elements. Trace elements refer to any chemical element that is present in the human body in very small amounts. Trace elements are an essential part of our diets because they are needed for our cells to function properly.
Zinc is particularly important for the proper functioning of the immune system. People with mutations that affect their ability to absorb zinc, or people who have a zinc deficiency, are susceptible to a wide range of infections.
How could zinc make colds go away faster?
Dr Brent Bauer, an expert in Alternative Medicine at Mayo Clinic in the USA says “Most colds are caused by a type of virus called rhinovirus, which thrives and multiplies in the nasal passages and throat (upper respiratory system). Zinc may work by preventing the rhinovirus from multiplying. It may also stop the rhinovirus from lodging in the mucous membranes of the throat and nose.
Not only is zinc important for the proper functioning of the immune system but also may have direct effects against pathogens (the agents that cause diseases). Dr Divya Ramnath, an expert in Infectious Diseases from University of Queensland in Australia explains “Many metal ions, including Zinc, are toxic to pathogens. This is particularly well-established in the case of diarrhoea, where zinc supplements help manage it.”
Dr Bauer adds “Zinc may be more effective when taken in lozenge or syrup form, which allows the substance to stay in the throat and come in contact with the rhinovirus.”
What is the evidence that zinc helps colds?
Many studies including clinical trials have looked at whether zinc helps beat colds. Dr Bauer explains that “research has turned up mixed results about zinc and colds. Recently an analysis of several studies showed that zinc lozenges or syrup reduced the length of a cold by one day, especially when taken within 24 hours of the first signs and symptoms of a cold.”
He goes on to say that “recent analysis stopped short of recommending zinc. None of the studies analysed had enough participants to meet a high standard of proof. Also, the studies used different zinc dosages and preparations (lozenges or syrup) for different lengths of time. As a result, it's not clear what the effective dose and treatment schedule would be.”
Professor Harri Hemila an expert in Epidemiology from University of Helsinki in Finland elaborates “Three randomised trials with zinc acetate lozenges found that on average the rate of recovery was about 3 times faster in the zinc groups compared with the placebo groups.”
However, not all trails show a benefit from zinc, as Professor Hemila explains “We have published a new trial on zinc lozenges in 2020. That study did not find benefit from zinc acetate lozenges. However, low dose of zinc, small size of lozenges and the short 5-day treatment were considered potential explanations for the negative finding. Furthermore, a substantial decrease in the rate of recovery in the zinc participants was seen after the 5-day treatment ended which could be caused by the rebound effect so that the discontinuation of the zinc lozenge treatment had a physiological effect in the harmful direction.”
Should I take zinc when I get a cold?
Professor Hemila highlights one of the differences between the zinc researchers use in their studies with the zinc you can buy in your local pharmacy. She says that “Although there is strong evidence that properly composed zinc lozenges can increase the rate of recovery from the common cold, the majority of zinc lozenges on the market appear to have either too low doses of zinc or they contain substances that bind zinc ions, such as citric acid. Thus, the results of the randomised trials should not be directly extrapolated to the wide diversity of zinc lozenges on the current market.”
Professor Hemila concludes that “there is strong evidence for the concept that zinc lozenges can be beneficial for treating colds, but the characteristics of zinc lozenges that are clinically efficacious should be evaluated in detail before they can be widely promoted for common cold treatment.”
Dr Bauer adds a warning: “Zinc - especially in lozenge form - also has side effects, including nausea or a bad taste in the mouth. Many people who used zinc nasal sprays suffered a permanent loss of smell. For this reason, Mayo Clinic doctors caution against using such sprays. In addition, large amounts of zinc are toxic and can cause copper deficiency, anaemia and damage to the nervous system. For now, the safest course is to talk to your doctor before considering the use of zinc to prevent or reduce the length of colds”
The takeaway:
Whilst trials have shown that some preparations of Zinc can make colds go away quicker, most preparations you can buy in a shop will not - and high doses of Zinc may have harmful side effects.
May the facts be with you!
Eva
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