The Full Story
It's called the "common cold" because just about everyone gets colds. Most of us suffer through several colds a year. So far, there's no good way to prevent colds. And, so far, there's no good way to treat them, either.
Symptoms of the common cold range from a slight stuffy nose, cough, and tiredness to non-stop sneezing, a hacking cough, and sore throat. You might have some muscle aches, a slight fever, and you might feel tired. (By contrast, these symptoms plus a high fever are more likely to be influenza. Usually, flu can be prevented or lessened by getting flu vaccinations.) Cold symptoms usually last for one to two weeks; most people with colds get better on their own.
Cold medicines provide some symptom relief but there is no cure for colds. Searching for a way out of their misery, many people turn to vitamins and supplements in the hope of feeling better. Do these "alternative therapies" work to prevent or treat colds?
Echinacea (coneflower) has a long history of use to prevent and treat colds. Scientific studies are mixed as to its effectiveness. For example, a 2007 review of published studies [Shah] reported that people who took Echinacea had fewer and shorter colds. On the other hand, in a 2010 study of more than 700 people [Barrett], Echinacea did nothing to reduce cold symptoms.
The good news is that people did not seem to be harmed by taking Echinacea supplements. There was one episode of gout in the Echinacea treatment group and one episode of severe headache in the non-Echinacea group. Clearly, the headache was not related to Echinacea; it is not known if the single episode of gout was related.
Zinc lozenges and tablets might shorten the time that cold symptoms last in adults. Researchers evaluated seventeen studies involving more than 2,000 people [Science]. They found that adults who took oral zinc at the start of a cold suffered from their symptoms for a shorter time; on average, they felt better 1.65 days sooner. It's important to note three things:
- These results were for adults. Children were not helped by taking zinc.
- The studies used zinc supplements taken by mouth.
- A lot of people had side effects, especially nausea and a bad taste.
Researchers warn that treatments should be benign for a problem that cures itself. That is clearly not true for zinc nasal swabs and nasal gels. Zinc nasal swabs and gels must not be used. More than one hundred people lost their sense of smell after using these products. In some cases, the loss of smell was permanent. Some people lost the ability to smell after using intranasal zinc once; others used it a number of times. Not being able to smell means not being able to taste. But, more importantly, it means not being able to smell smoke, leaking gas, or bad food. Intranasal zinc supplements were taken off the market in 2009.
Vitamin C has been recommended as prevention and treatment for colds for decades, though most studies show it is not effective. In a review of studies involving more than 11,000 people (Hemilä), researchers found that:
- Taking vitamin C regularly did not prevent people from getting colds. (An exception was in people involved in vigorous exercise, for example soldiers in subarctic conditions.)
- Some studies showed that taking vitamin C regularly might lessen cold symptoms.
- People who took vitamin C when a cold started did no better than people who took a placebo.
Garlic: We don't really know if garlic supplements help prevent or treat the common cold. In a review of several published studies about garlic supplements and colds, researchers found only one study that met their scientific standards [Lissiman 2012]. In that study of 165 people, those who took garlic supplements daily for at least three months had fewer colds than people who took a placebo. If they did get a cold, on average they felt better about 24 hours sooner [Josling]. Side effects of the garlic supplement included an itchy rash in one study subject; it went away after the person stopped taking the garlic supplement. In short, evidence is slim for the effectiveness of garlic supplements, but most people tolerated them without problems.
The bottom line for preventing colds remains the tried-and-true:
- Wash your hands often. If you aren't near soap and water, use hand sanitizer.
- Try not to touch your face, eyes, and nose.
- Keep your germs to yourself! Cover your coughs and sneezes. Cough or sneeze into a tissue. Or, cough and sneeze into the bend of your elbow.
- If possible, avoid people who have colds.
- If you have a cold, avoid other people if you can.
The medical term is "symptomatic relief". In other words, make yourself as comfortable as possible until your cold symptoms go away.
- Drink lots of fluids.
- Take over-the-counter medicines to treat only the symptoms you have. For example, take a fever-reducer if you have a fever or a cough suppressant if you have a cough. It's best not to take multi-symptom cold remedies unless you have every symptom on the label.
- Read labels carefully! It's easy to overdose by taking two medicines with the same ingredients. For example, both your fever reducer and multi-symptom cold product might contain acetaminophen.
- Eat according to your appetite, but drink plenty of fluids. Don't worry about the old advice about "feed a cold and starve a fever" - or was it "starve a cold and feed a fever"?
If your cold doesn't get better in a week or ten days, if you have a high fever, or if you have a bad cough, give your doctor a call. If you have questions about your cold medicines, call Poison Control at 1-800-222-1222. If you suspect someone swallowed too much or the wrong medicine, use the webPOISONCONTROL® online tool or call Poison Control right away.
Rose Ann Gould Soloway, RN, BSN, MSEd, DABAT emerita
Barrett B, Brown R, Rakel D, Mundt M, Bone K, Phyto D, Barlow S, Weres T. Echinacea for treating the common cold. Ann Intern Med 2010;153:769-777.
Food and Drug Administration. Public Health Advisory: Loss of sense of smell with intranasal cold remedies containing zinc. June 16, 2009.
Hemilä H, Chalker E, Douglas B. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2007; Issue 3. Art. No.: CD000980. DOI: 10.1002/14651858.CD000980.pub3.
Josling P. Preventing the common cold with a garlic supplement: a double-blind, placebo-controlled survey. Advances in Therapy 2001;18(4):189–93.
Lissiman E, Bhasale AL, CohenM. Garlic for the common cold. Cochrane Database of Systematic Reviews 2012; Issue 3. Art. No.: CD006206. DOI: 10.1002/14651858.CD006206.pub3.
Science M, Johnstone J, Roth DE, Guyatt G, Loeb M. Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials. CMAJ 2012;184(10):E551-E561. DOI:10.1503/cmaj.111990.
Shah SA, Sander S, White CM, Rinaldi M, Coleman CI. Evaluation of Echinacea for the prevention and treatment of the common cold: a meta-analysis. Lancet Infect Dis 2007;7:473-80.
Van Straten M, Josling P. Preventing the common cold with a vitamin C supplement: a double-blind, placebo-controlled survey. Advances in Therapy 2002;19:151-159.