We are, alas, heading into winter, which is not only the cold (Brrr!) season, but also the cold (Ah-choo!) season.
We all get colds. That’s not surprising, because, as the Common Cold Centre at Cardiff University in the U.K. likes to point out, we breathe in some 15,000 litres of germ-laden air every day.
Which is why New Scientist magazine’s Brussels correspondent Debora MacKenzie did us all (and especially me, since I got this column out of it) a favor last week by posting “Eight Cold Facts” on the New Scientist Short Sharp Science Blog. She presented eight statements you’ve probably heard about colds, and then detailed whether they’re scientifically accurate.
First off: “Colds are caused by a weakened immune system.” Not normally, MacKenzie writes. In fact, since cold symptoms are your immune system’s response to the cold, having a strong immune system might actually make your symptoms worse. On the other hand, a weakened immune system can allow the cold viruses to spread further than they would otherwise, which can lead to serious, even fatal, complications.
Second: “Colds happen in winter because central heating dries out your nose.” No. Experiments have shown that once the virus is in your nose, humidity doesn’t make much difference.
Third: “Stress causes colds.” Yes. If you’ve just gone through a major life event, such as getting married or losing a loved one, you’re more prone to colds because, when you’re under stress, your immune system triggers inflammation reactions more readily–and it’s those reactions that give us cold symptoms. According to MacKenzie, if you’re happy and calm you may be three times less likely to get sick than if you are anxious. (Which is just one more thing to lie awake at night and worry about: “Am I happy and calm enough?” So really, you can’t win this one.)
Fourth: “Feed a cold and starve a fever.” Maybe. Starving a fever might, in some cases, starve germs of the nutrients they need, giving your body an edge in fighting them off. Colds don’t usually give adults fever, but those muscle pains you sometimes feel are caused by the body recycling proteins from your muscles into defensive proteins. In that case, eating to replenish those proteins could help your symptoms. Something like, for example, chicken soup, which also warms the upper respiratory tract, one way to help keep cold viruses in check.
Fifth: “Blowing your nose helps clear out the virus.” Nope. A blocked nose is usually due to dilated blood vessels. Blowing it won’t help, and blowing your nose forcefully, MacKenzie writes, can actually help spread viruses and inflammatory substances into your sinuses, making your symptoms worse.
Sixth: “Green snot means you need antibiotics.” No, it has nothing to do with bacteria. Mucus can turn green any time you have a bad respiratory infection. The color comes from an enzyme in white blood cells which uses a green iron-containing molecule to catalyze the chemical reactions that kill germs.
Seventh: “Large doses of Vitamin C prevent colds.” We’ve all heard this one, but, says MacKenzie, “not unless you run marathons or work out in the snow.” The Vitamin C-prevents-colds idea has been repeatedly disproved since Linus Pauling first put the notion out in the 1970s, but that fact doesn’t seem to have sunk in.
However, while Vitamin C doesn’t do anything for ordinary people, it does appear to “halve the risk of getting colds for marathon runners, skiers and soldiers on subarctic exercises.”
(MacKenzie adds that Echinacea may shorten colds a bit but has side effects and doesn’t prevent colds. Zinc lozenges work better.)
Finally: “Red wine helps.” Yes, says MacKenzie. It doesn’t cure colds, but according to a Spanish study, people who drank more than 14 glasses of red wine a week (but not spirits or beer) almost halved their risk of getting a cold.
The best ways to avoid a cold, according to MacKenzie (writing in New Scientist itself, not on the blog) are to keep your nose warm, wash your hands a lot, and stay away from children.
As the father of a small child, I guess I’m stuck taking the red wine approach.
Darn.
