Preventing and treating colds: The evidence and the anecdotes

Oh, who doesn't hate colds. You're miserable, achy, tired, congested, and coughing. You may need to miss work, or go to the doctor. But it seems that no one really feels sorry for the person with a cold because colds are so common. "It's just a virus, it'll get better on its own," says your doctor. "There's no cure."

Well, colds cost the U.S. an estimated 40 billion dollars per year considering lost financial productivity, plus spending on medical care, pharmaceuticals, and supplements (and that estimate is from 2003)!¹ It's just a virus? There's got to be more we can do to effectively prevent and treat this veritable scourge on society.

As a primary care doc, here's what I do for colds in my family (including me) … and the scientific evidence (or lack thereof) behind these recommendations.

How to keep colds from happening in the first place

There are several basic and effective methods that can help you avoid colds altogether.² These are really obvious, but obviously not practiced enough.

1. Stay home when you're sick (and keep your kids home when they're sick, too). Yup, the first step in prevention is to not go out when you're spewing viral particles, and that will help prevent other people's infections. Can't get time off of work? Stay far away from others, sneeze into a tissue or your elbow, and wash your hands to avoid contaminating surfaces (see below).
2. Wash, wash, wash your hands. Seriously, this is not an old wives' tale. Handwashing is incredibly well-studied and extremely effective.³ The trick is, you have to wash your hands correctly. The CDC has a tutorial video on this.⁴ I'll break it down for you: Soap up. Lather well. Scrub while singing "Wash, wash, wash the germs, gently down the drain, thoroughly, thoroughly, thoroughly, thoroughly, This is such a pain." Now rinse. Then dry, and use the paper towel to open the door. That doorknob is infested with germs. No towel? Use your sleeve.
3. Don't touch your face. It only takes a few virus particles to infiltrate your mucous membranes and make you sick. What are mucous membranes? The soft, moist, folds of your eyes (don't rub your eyes!), nose (don't pick your nose!) and mouth (don't bite your nails/pick your teeth/lick your fingers!).

If everyone did these three things, I have no doubt that multiple hours of misery could be avoided and billions of dollars could be saved.

There have been multiple variable-quality studies of all sorts of other potential preventives. Looking the available data, there is weak evidence to support regular probiotics and zinc, but really no consistent evidence to support the use of vitamins C and D, echinacea, and ginseng.^5,6,7,8,9,10 I'll be honest, in my family we do not make any effort to take any of these things regularly. We all eat yogurt daily by habit, and my husband and I occasionally drop one of those fizzy "immune-boosting" supplements into water and down it. The citrus-y fizziness tastes good, but the science says, if there is any benefit at all, it's probably from the hydration.

"Natural" cold remedies

So now you've got a cold. What treatments are effective? If you want to go all-natural, then there is weak evidence showing that honey, just a tablespoon of plain old honey, can help with the cough associated with the common cold, especially in children.^11,12,13,14 The physiologic mechanism for this is unclear, but it may explain why we get temporary relief from sugary cough drops. (Note: Never give honey to children under a year of age due to risk of botulism.)

There is inconsistent evidence showing that zinc lozenges can slightly shorten the duration of a cold by a day or two, though only in adults, and many people will hate the taste or get nauseated from these.^5,7 Zinc nasal swabs have been associated with sudden loss of the sense of smell, and so cannot be recommended at all. Despite many studies, there is no consistent evidence showing that vitamin C, echinacea, nasal saline irrigation, garlic, or humidifiers help at all.^5,8,10,15

If you want to try more traditional treatments

As far as the items in the "cough and cold" aisle of your local pharmacy, decongestants (such as pseudoephedrine) as well as decongestant-antihistamine combos have been shown to alleviate cold symptoms.^{5, 16,17,18} Of note, an ever-popular nighttime cold and cough formulation contains an older, particularly sedating antihistamine called doxylamine, which is why I believe it helps people with colds to sleep. Ditto with the prescription cough medicines that contain codeine or hydrocodone. One other prescription product of iffy effectiveness is nasal ipratropium, which has some effect on nasal runniness, but not on congestion. So, you'd be wiping your nose less, but still stuffy.¹⁹ Probably not worth the copay. And nasal steroids don't help here at all.²⁰

What else might work? One thing that we use a lot in our family but has not been extensively studied is those menthol- or camphor-based rubs and inhalants. You know, like your mother used to slather all over your throat and chest and made you and your entire room smell like a eucalyptus tree. There's been exactly one study on this, involving only 138 children, but there was a significant improvement of symptoms and quality of sleep.²¹ That's not enough to make any sweeping statements, but hey, it seems to work for us, so I'm throwing it in here.

In the end, prevention is king, and the treatments for colds are basic.

References

1. The Burden of Non–Influenza-Related Viral Respiratory Tract Infection in the United States Mark Fendrick, MD; Arnold S. Monto, MD; Brian Nightengale, PhD; et al Matthew Sarnes, PharmD, Archives of Internal Medicine 2003.
2. cdc.gov/Features/Rhinoviruses/
3. cdc.gov/handwashing/publications-data-stats.html
4. cdc.gov/handwashing/index.html
5. Prevention and treatment of the common cold: making sense of the evidence. Allan GM, Arroll B. Canadian Medical Association Journal, February 18, 2014.
6. Probiotics for preventing acute upper respiratory tract infections. Hao Q, Dong BR, Wu T. Cochrane Database of Systematic Reviews. February 3, 2015.
7. Zinc for the common cold. Singh M, Das. RR Cochrane Database of Systematic Reviews, February 16, 2011.
8. Vitamin C for preventing and treating the common cold. Douglas RM, Hemilä H, Chalker E, Treacy B. Cochrane Database of Systematic Reviews, July 18, 2007.
9. Effect of vitamin D₃ supplementation on upper respiratory tract infections in healthy adults: the VIDARIS randomized controlled trial. Murdoch DR, Slow S, Chambers ST, Jennings LC, Stewart AW, Priest PC, Florkowski CM, Livesey JH, Camargo CA, Scragg R. Journal of the American Medical Association, October 3, 2012.
10. Echinacea for preventing and treating the common cold. Karsch-Völk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Cochrane Database of Systematic Reviews. February 20, 2014.
11. Effect of honey, dextromethorphan, and no treatment on nocturnal cough and sleep quality for coughing children and their parents. Paul IM, Beiler J, McMonagle A, et al. Archives of Pediatric and Adolescent Medicine
12. A comparison of the effect of honey, dextromethorphan, and diphenhydramine on nightly cough and sleep quality in children and their parents. Shadkam MN, Mozaffari-Khosravi H, Mozayan MR. Journal of Alternative and Complementary Medicine
13. Effect of honey on nocturnal cough and sleep quality: double-blind a. randomized, placebo-controlled study. Cohen HA, Rozen J, Kristal H, et al. Pediatrics, September 2012.
14. Honey for acute cough in children. Oduwole O, Meremikwu MM, Oyo-Ita A, Udoh EE. Cochrane Database of Systematic Reviews, December 23, 2014.
15. Garlic for the common cold. Lissiman E, Bhasale AL, Cohen M. Cochrane Database of Systematic Reviews, November 11, 2014.
16. Nasal decongestants in monotherapy for the common cold. Deckx L, De Sutter AI, Guo L, Mir NA, van Driel ML. Cochrane Database of Systematic Reviews, October 17, 2016.
17. Treatment of the common cold in children and adults. Fashner J, Ericson K, Werner S. American Family Physician, July 15, 2012.
18. Over-the-counter (OTC) medications for acute cough in children and adults in community settings. Smith SM, Schroeder K, Fahey T. Cochrane Database of Systematic Reviews, November 24, 2014.
19. Intranasal ipratropium bromide for the common cold. AlBalawi ZH, Othman SS, Alfaleh K. Cochrane Database of Systematic Reviews, June 19, 2013.
20. Corticosteroids for the common cold. Hayward G, Thompson MJ, Perera R, Del Mar CB, Glasziou PP, Heneghan CJ. Cochrane Database of Systematic Reviews, October 13, 2015.
21. Vapor rub, petrolatum, and no treatment for children with nocturnal cough and cold symptoms. Paul IM, Beiler JS, King TS, Clapp ER, Vallati J, Berlin CM Jr, Pediatrics, December 2010.