There's a flu shot for the flu, but what about colds? Does anything work? Let's find out. This is Healthcare Triage.

[Healthcare Triage Intro]

Echinacea. Studies including as many as 3000 people have looked at whether Echinacea prevents colds or whether it treats them. For neither purpose does Echinacea stand up to scrutiny. It's hard to do a meta-analysis (and I hope you watched that episode) because studies look at different parts of the plant, they use different methods for each of the studies.

But, in 2006, a Cochrane systematic review was published. In 16 studies of the herb, Echinacea did no better than placebo for preventing or treating colds. In the best studies, which were randomised controlled trials, the majority of studies still found no benefit for Echinacea in preventing colds. Studies done since then aren't any more convincing. In 2007, a group of researchers claimed that the evidence from 14 studies suggested that Echinacea did shorten cold symptoms by a day or so. Unfortunately, other researchers claim that those scientists didn't combine the studies and that the results can't be trusted.

Bottom line, even in the weakest studies the evidence isn't really compelling. And let's face it, results from the better quality studies are more trustworthy. Those studies say that Echinacea doesn't prevent or treat colds.

Garlic. Taking garlic to prevent or treat colds requires some serious trade-offs. Is it better to smell terrible and be accused of excessive paranoia about avoiding vampires or to have the occasional cough or cold?

In a comprehensive review of scientific trials of garlic, only one of the five studies identified was of really high quality. In that study, 146 volunteers were randomly assigned to take a garlic supplement every day for 12 weeks or to take a fake placebo pill. Interestingly enough, the volunteers who were taking garlic had significantly fewer colds than the volunteers who were taking the placebo. The garlic group also had fewer days of illness overall. But the number of days it took for people to recover from their illnesses was the same for both groups.

So garlic just might work. Of course, those taking garlic did have some serious side effects. They reported more rashes and, not surprisingly, having a bad odour. Because this was just one study, the verdict on garlic is still out. But, the one small study suggests that garlic might prevent you from getting a cold if you take it regularly for a long period of time.

Vitamin C. On the other hand, there's been a lot of research on Vitamin C. When researchers combine the results of 23 studies investigating whether Vitamin C prevents colds in normal people, there's no significant improvement. Vitamin C doesn't prevent you from getting a cold. In studies involving over 11 000 people, taking 200mg or more of Vitamin C a day, it didn't prevent colds.

We're being totally thorough, though. And there is a study that showed that people who engaged in extreme exercise in extreme conditions (think, like, marathon runners, soldiers training in the Arctic, and skiers), Vitamin C almost looked like it worked to prevent colds. But it still made an insignificant difference. So if you plan on engaging in seriously strenuous exercise in very cold conditions, you might consider taking Vitamin C in the hope that it might work. But otherwise, don't waste your time.

Vitamin C also doesn't treat colds. In 7 studies looking at the treatment of the common cold, scientists found it to be no better than placebo. Based on the results of 11 studies of more than 6000 people, taking Vitamin C also didn't make colds any shorter or any less severe. It doesn't work.

Zinc. There's a systematic review of 7 studies that look at whether zinc lozenges effectively treat the common cold. The results are mixed. In about half of them, zinc did nothing. And in the other half, it did. The authors concluded that there might be a small help from taking zinc, but they acknowledged that most studies are of pretty poor quality.

But zinc's got issues. One of the problems is that it tastes terrible. Researchers couldn't make a placebo pill that tasted as uniquely bad as zinc. So studies are often poorly blinded. It's also important to note the other downsides. It's more likely to make you feel nauseous than it is to improve cold symptoms. People who use zinc lozenges are also more likely to have distortions in their sense of taste and irritation of the mucosa in their mouths.

There's an added zinc-related caution. Older studies of zinc nasal gel showed it actually improved cold symptoms and how long colds last. But, putting zinc nasal gel in your nose permanently damaged your sense of smell. Losing your sense of smell and your sense of taste, which is affected by how well you can smell, is a terrible price to pay for shortening a cold. Makers of zinc nasal gels have actually paid out over $12 million in lawsuits from people who damaged their sense of smell permanently because of zinc. Don't do it. Bottom line is that zinc might help your cold a bit but the downsides likely outweigh the benefits.

Airborne is a popular supplement among school teachers who claim that it prevents them from picking up all the germs spread around their classrooms full of sick children. The Airborne package even tells the moving story of how it was created by a school teacher who was frustrated with just that problem. Given what it says on the package, it may surprise you to hear that Airborne hasn't been studied scientifically.

Since Airborne is an herbal supplement, it's not regulated by the FDA and it's makers aren't required to tell us exactly what's in it. All we know is that Airborne contains a mixture of vitamins, minerals and herbs, including large amounts of Vitamin C and Vitamin A as well as some zinc. And we know those things don't really work.

The package used to talk about a "double-blinded, placebo-controlled trial of 120 patients" that showed that Airborne worked to make colds better. It's not there anymore. Why? The makers of Airborne had to remove that claim because, as it turns out, the "study" was conducted unscientifically. An investigative report by ABC News found that the scientific team at GNG Pharmaceutical Services was, in fact, two men working in a garage. Well, that's not a problem in and of itself but it turns out lots of other stuff wasn't as good as originally sold either. The makers of Airborne agreed to pay more than $24 million to settle a class action lawsuit in regard to their false advertising about this garage "study" and the lack of evidence for their product. Airborne is not Healthcare Triage approved.

Chicken soup. Let's start off by saying that chicken soup hasn't been tested at rigorous clinical studies. There are no randomised controlled trials or even any real clinical trials. That said, one group of researchers did carefully investigate the impact of chicken soup on the specific cells of the immune system that increase inflammation when you have an infection.

So, when you have an infection, immune cells called neutrophils migrate to the area to help fight an infection. One of those things the neutrophils do is release chemicals that increase the amount of inflammation going on in your body. This inflammation is part of why you develop more mucus and phlegm when you have a cold. Scientists studied whether chicken soup had an impact on the inflammation response. They looked at homemade chicken soup as well commercially prepared soups to determine whether they prevented the inflammatory cells from migrating or moving to a source of infection. Amazingly enough, they did! Various dilutions of the homemade soup and the majority of the store made soups inhibited the movement of the neutrophil cells, which might give chicken soup some anti-inflammatory properties.

And we own that this isn't a randomised controlled trial with clinical outcomes but chicken soup has other properties that might help you to feel a bit better. Even if those are placebo effects. Having soup prepared for you by a loved one or associating chicken soup with memories of someone taking care of you may play a powerful role in making you feel better. Chicken soup is not a cure for the common cold but it might be worthwhile to listen to grandma on this one. You just might feel a bit better, and there's really no downside and that's the important point. Unless you don't like chicken soup, and then, god, I don't even want to know you.

[Healthcare Triage Outro]