Colds and Zinc

Catching a cold and suffering through the symptoms is one of the universally shared experiences we have as humans. There are over 100 types of virus that cause colds and they may mutate. Therefore, while older people tend to get fewer colds because they have immunity for most strains, nobody is completely exempt. Colds can also affect people differently, depending on a number of factors. Everyone who has a cold wishes there were a cure.

There are some myths associated with colds — for example, that being out in the cold and getting chilled causes a cold. In reality, colds are caused by those viruses being transmitted from person to person and generally have nothing to do with being out in the cold.

What follows is based on my memories and experience. I am not making any medical recommendations. Back around the late 1970s to early 1980s there was a report in a popular science magazine (“Science 80″ or “Science 81″, perhaps) from a man (George Eby) whose young daughter had to take zinc supplements. Sometimes instead of swallowing the tablet she held it in her mouth. One of those times she was starting to get a sore throat. Curiously, the zinc tablet held in her mouth, dissolving slowly, seemed to help the sore throat. According to the article, zinc deactivates the cold virus on contact in the throat, so simply swallowing the tablet doesn’t help; and the cold virus takes about twenty minutes to replicate, so a constant flow over the throat of small amounts of zinc from the lozenge is needed for about that length of time.

I have been trying zinc lozenges (first as tablets) ever since I read that article about thirty years ago. I have learned to take one as soon as I feel soreness starting in the back of my throat, since waiting just half a day makes it much less effective. In my experience, if I act quickly, the zinc lozenges (I usually take another one after a few hours) prevent the spread of the sore throat and can even stop it completely.

Now there are also zinc gel preparations to apply inside your nose. In my experience these work well in combination with the lozenges. As for safety, the most common side effect I have experienced is heartburn so I take an acid-reducer before the zinc lozenge. When I use this treatment my colds are not cured but the symptoms are greatly reduced and shortened. (There is an update below about Zicam, the zinc gel preparation sold to apply inside the nose.)

But am I just barking at my food? There are a lot of studies that apparently show no effect for zinc lozenges. And since I am older, you might argue I’m just getting fewer colds anyway. I can’t know what might have happened, or not, if I hadn’t taken the zinc tablet. It doesn’t help that George Eby’s website looks like he’s claiming he’s got a cure for nearly everything. Even worse, The Straight Dope, that bastion of popular rationality, comes down on the side of “no effect.” The Wikipedia (currently) manages to be on both sides of the issue. The beginning of the article emphasizes that overall, studies do not support zinc being an effective treatment for colds, but lower down in the same article it emphasizes  that some studies have. Presumably this is because different parts were written by different people.

Nevertheless I think the lozenges really do have an effect but it requires some experience to take them as soon as symptoms start. If your entire throat is sore it’s too late already. I suspect that in the studies showing no effect, the subjects were inexperienced and waited too long before taking the zinc. But that’s just a guess. Years ago I tried large doses of vitamin C without any clear effect so I stopped. I’m going to continue taking zinc lozenges when I feel a cold starting, because so far they seem to work.

Update:
June 17, 2009

The FDA just released a statement advising consumers to stop use of Zicam intranasal products which contain zinc. The reason given was that in the past ten years, “over 130 people” have complained of a loss of their sense of smell (anosmia) after using Zicam in their nose. (It should be noted that the statement says nothing about zinc lozenges taken by mouth.)

There are several interesting features of this FDA statement. First, I don’t know whether or not Zicam is responsible for the anosmia those people experienced. However, it is not clear how many people used Zicam without experiencing anosmia. Possibly millions, which would likely make Zicam safer than say, aspirin. Furthermore, if you search for “anosmia” in Medline, the NIH medical encyclopedia, you’ll find the following:

Temporary loss of the sense of smell is common with colds…

There is no indication of how many of the 130 complaints were about temporary anosmia. Not only that, but you’ll also find, further down on the same page:

For loss of smell caused by a recent viral upper respiratory infection, be patient. The symptoms return to normal without treatment. Sometimes zinc supplements are recommended.

Of course, those zinc supplements recommended to cure anosmia would be taken by mouth, not intranasally. But it is ironic that the FDA flags a compound as causing anosmia when the same compound could be given as a cure for that condition. Kind of a strange homeopathy.

Which brings me to another point. Zicam was sold as a homeopathic remedy, presumably because the company could not afford to perform the kinds of tests the FDA requires for non-homeopathic drugs. The active ingredient itself is apparently not patentable, so the company would not be able to recoup their costs in the usual way with a temporary monopoly. But some of the articles reporting on the FDA announcement also noted that there are problems with most homeopathic remedies — mainly that they do not work — and used that fact, by implication, to make Zicam look bad.

I have no sympathy for companies that peddle most homeopathic remedies. But I understand why Zicam had to go that route. At the same time I regretted that Zicam was advertised as homeopathic, because I did not like the idea that people might think more highly of other homeopathic medicines if they found out that Zicam worked.

And now the other side of that coin shows up in the reports about Zicam. Since homeopathic remedies are shams, then Zicam must be a sham too… and it destroys your sense of smell.

The fallacies in the logic used in the statement denouncing Zicam makes me wonder if there’s something else going on here. Could the large pharmaceutical companies who have made so much money on selling cold remedies that don’t work, be putting pressure on the FDA to discourage people from using one of the only drugs that actually does work?

I have no idea, and I’m not a fan of conspiracy theories (except when they are true) and I have no evidence for any collusion between the FDA and drug companies. However, I have used Zicam many times and I can still smell a rat.

Meanwhile, Matrixx, the makers of Zicam, have taken it off the market (read their statement here). While I am disappointed in the FDA’s decision, I also should say that in general the FDA has done a good job of keeping the American public safe. Too often an unregulated food or drug industry has caused significant harm to consumers in the past, in the USA and in other countries. This time, however, it isn’t so clear.