On The Shelf
Mickie Cathers
COVID-19 may have pushed the common cold out of the limelight, but we’re about to enter a new cold season. While there is a vaccine for COVID-19, there is no vaccine or cure for the common cold. Some patients, with typical complaints of congestion, runny nose, sore throat, coughing, and sneezing, may reach for remedies like echinacea, ginger, or zinc. But do any of these help?
In the United States, there are millions of cases of the common cold each year. Rhinoviruses, which spread through coughing, sneezing, or frequently touched surfaces and objects such as doorknobs or mobile devices, are the major cause of colds. The first signs of a cold usually include a sore throat and runny nose, with coughing and sneezing following close behind. Most colds last about 7 to 10 days—a week of discomfort that has most people reaching for quick remedies.
OTC products can alleviate some symptoms and patients interested in nonpharmacological remedies to alleviate cold symptoms may ask about the effectiveness of echinacea, garlic, ginger, honey, probiotics, vitamin C, and zinc. Patients may also inquire about a neti pot, a saltwater sinus wash, mentholated chest rub, or even a can of chicken soup to treat the common cold.
Lemon, honey, ginger, and zinc
A warm mug of lemon, honey, and ginger tea may have some benefit for cold sufferers. While the lemon may provide some antibacterial properties, and a balanced and healthy diet that contains vitamin C positively affects the immune system and reduces susceptibility to infections, there is no significant clinical data to support the theory that vitamin C affects the duration or severity of the common cold.
However, the honey and ginger may provide relief. A Cochrane Database systematic review published in 2018 found that honey likely reduces cough frequency better than no treatment or a placebo, is just as effective as dextromethorphan, and may be better than diphenhydramine and salbutamol for soothing a cough. Honey coats and soothes the back of the throat and offers antioxidant, antibacterial, and anti-inflammatory effects.
Ginger has been studied as a remedy for sore throat, nausea, and vomiting, and it has been found to be effective for treating respiratory disease. Ginger also has antiviral activity; a 2013 study by Chang and colleagues in the Journal of Ethnopharmacology found that 300 μg/mL of fresh ginger, in contrast to dried ginger, inhibited respiratory syncytial virus.
Congestion and the inability to breathe out of your nose can be addressed with a sinus wash using salt water. A 2022 review by Stanfel and colleagues in Marine Drugs showed positive effects of nasal irrigation solutions in cleaning the mucosa, reducing swelling, and moisturizing the upper respiratory tract. And a 2007 randomized controlled clinical trial in JAMA Network confirmed clinically significant improvement from nasal irrigations for the treatment of chronic nasal and sinus symptoms.
Zinc is an essential nutrient that supports immune health and by reducing the degree of an inflammatory reaction to infection, zinc can contribute to reduced achiness, fatigue, and other symptoms of a cold.
Zinc supplements have even been shown to prevent pneumonia. Several studies have explored the efficacy of zinc lozenges—which are soothing for a sore throat—in reducing the incidence, duration, and severity of the common cold.
A 2017 meta-analysis in the Journal of the Royal Society of Medicine Open found the duration of common cold was 28–40% shorter when patients used zinc, with no significant difference between high- and low-dose zinc. Recommended daily intake of zinc ranges from 8–11 mg/day for adults, and studies show no evidence that zinc doses over 100 mg/day led to better efficacy in treating the common cold.
No meaningful benefit
Echinacea, garlic, probiotics, and vapor rubs for treatment of the common cold each lack consistent quality evidence. Likewise, vitamin C is considered no more effective than placebo in reducing symptom duration or severity of the common cold. Notably, while zinc has shown benefit in the treatment of the common cold in adults, there has been no evidence showing benefit for children.
But what about chicken soup?
There may be a good reason chicken soup has been a go-to remedy for cold symptoms for decades. Research suggests that chicken soup with vegetables may help fight infection by concentrating neutrophils in the area that requires healing.
In a special report published in Chest in 2000, Barbara Rennard and colleagues described a study of a “traditional chicken soup” and found inhibitory activity present in all of the vegetables and the chicken individually with no cytotoxic activity.
The study concluded that a mild anti-inflammatory effect may be one way in which chicken soup could mitigate upper respiratory infections.
However, the authors wrote in a letter published in Chest 20 years later that, as their research was not a clinical trial, it’s possible that most of the benefit derived from chicken soup could be from the psychosocial support inherent in patients receiving care and the reassurance that comes from “doing something.”
What to tell your patients
Signs and symptoms of the common cold, influenza, and COVID-19 overlap, so it is even more important to recommend that patients see their primary care provider if their symptoms last more than 10 days, are severe or unusual, or if a sick child younger than 3 months has a fever or is lethargic.
Patients with weakened immune systems, asthma, or respiratory conditions should take precautions to avoid developing serious illnesses such as bronchitis or pneumonia.
Advise patients that they can protect others when they have a cold by staying home; avoiding hugging, kissing, or shaking hands with others; and moving away from others when coughing or sneezing.
Recommend patients cough or sneeze into a tissue or into a shirt sleeve, not their hands, and that they wash their hands frequently. Also, disinfect frequently touched surfaces and objects, including mobile devices.
For patients suffering symptoms of the common cold, zinc, fresh ginger, honey, and a saltwater sinus wash have all shown beneficial effects. And a nice warm bowl of low-sodium soup combined with rest might go a long way to feeling better. ■