Vitamin C, zinc, Echinacea: what cold supplements really work? And even if they do, should you take them?
You Know When It Hit You!
A runny nose, headaches, sneezing – you know when cold season made its personal yearly introduction to you.
At that point you just want relief. Maybe because you need to work. Or because you want to enjoy the winter vacation you looked forward to for the last six months.
Unfortunately, you’ll need to man (or woman) up if you got a cold, because the most popular cold supplements either don’t work or could make you feel worse in the long run.
Vitamin C: Useless For Most
Nothing beats vitamin C in popularity as a cold remedy. Unfortunately nothing beats vitamin C in ineffectiveness either:
- In a 1979 study, half of 764 Marine recruits took two grams of vitamin C per day. The other group got a placebo. There was no difference in severity or length of colds (PDF).
- In a similar setup, a 1984 study divided 528 people into a vitamin C and a placebo group. 47% of those in the vitamin C group got colds. In the placebo group it was 46%.
- In 2001, Australian researchers monitored 149 volunteers for 18 months and gave them either a 1 g or 3 g vitamin C supplements at the beginning of a cold and for the following two days. A third group received a placebo. Here too the researchers couldn’t note any difference in length or severity of the illness.
- A 2007 meta-analysis came to the conclusion that only for people under severe physical strain (marathon runners, soldiers in sub-arctic climates etc.) vitamin C can have a positive effect.
The overwhelming majority of us (yes, that includes recreational athletes) won’t benefit from vitamin C supps at all. Consumer Reports put it in prosaic fashion: they just make you produce expensive urine.
Zinc Works, But…
The second popular cold remedy really works: people who received zinc supplements a day after infection reduced their time under the spell by an entire day.
There are, however, two big caveats.
First of all, zinc is very aggressive. It doesn’t only kill the cold viruses it comes into contact with inside your body, but also the good and useful bacteria it needs. In the long run that may damage your immune system more than if you had it cope with the cold infection by itself.
The second is that the people who enjoyed a cold a day shorter often had side effects ranging from nausea to bad taste. Long-term usage can also lead to vomiting and diarrhea.
A cold remedy that became more popular in the last years are preparations made from Echinacea, a flower belonging to the daisy family.
As with the zinc, the respected Cochrane Review checked the available research. It concluded that there is no solid evidence that Echinacea products are effective in treating or preventing the common cold.
How To Really Avoid Colds
The two most effective strategies for avoiding colds are simple and free: washing your hands and sleep.
- Wash your hands when you touched public surfaces like door knobs, elevator buttons etc. They are the favorite hangout of cold viruses. If someone with a cold touched them before you, they transfer to your hands. From there they have a shortcut to the sensitive areas of your face (eyes, mouth, nostrils), as on average we touch our faces 3.6 times per hour (PDF).
- Your prime defender against infections is your immune system. Sleep is the time when it refills its artillery and gets ready to combat invaders the next day you face an unforgiving world. An impressive study highlighted that without enough sleep, you are three times more likely to catch a cold.
If You Already Have One
Have you ever heard the joke some doctors with an unshakeable sense of humor like to tell about treating colds? “The treated cold lasts seven days and the untreated cold lasts a week.”
If you already have a cold, rest and let your immune system do its thing.