An adult suffers between two and four colds a year; the children, from six to eight. These mild infections of the upper respiratory tract (they mainly affect the nose and throat), which present themselves in the form of mucus, sneezing and nasal congestion, are banal and generally low-risk, but very annoying. So much so that at the first symptoms, infallible remedies have been searched insistently at home or in the pharmacy to treat them. But it has not yet been possible to find the therapeutic key to neutralize or prevent these colds. For now, the only thing that has solid evidence are drugs and lifestyle recommendations to cope with the symptoms as best as possible. “There are no treatments that destroy the virus. Antibiotics do not work and there are no antivirals. We only treat symptoms,” summarizes José María Molero, coordinator of the Infectious Diseases working group of the Spanish Society of Family and Community Medicine.
Behind those symptoms of runny nose and congestion that announce a cold, there may be more than 200 different viral strains. Microorganisms from the rhinovirus, adenovirus, and coronavirus family (other than Sars-Cov-2) are usually the usual suspects, so antibiotics are not an option (these drugs are used for bacterial, not viral, infections) . There are also no preventive vaccines: “They were stopped due to their low effectiveness. Manufacturing a vaccine for dozens of serotypes is very difficult,” assumes Molero. The treatment is symptomatic, both for adults and children, insists Carlos Martín de Vicente, pediatric pulmonologist at the Miguel Servet Hospital in Zaragoza and member of the Spanish Society of Pulmonology and Thoracic Surgery: “There is no medication that can shorten the infection and there is no prevention, except for the measures that we had to apply with covid [distancia interpersonal, lavado de manos y usa mascarilla]”. The scientific community, however, does not give up its efforts and continues to look for therapeutic alternatives to combat colds.
A review by Cochrane, the independent network of researchers that analyzes scientific evidence, suggested a few months ago that zinc (in pills, nasal sprays and syrup) could reduce the duration of a cold from seven to five days, although the evidence was very limited. . The theory is that this mineral would have the capacity to interfere with the replication of the virus when it comes into contact with viral particles in the nose, mouth and throat. However, the authors of the analysis emphasized the limitations of the available evidence and warned that “more and better studies” were needed to be sure of the potential effects of zinc to reduce and prevent colds: the certainty that it can reduce the duration of symptoms is low, and they also found no solid evidence that zinc affects the intensity of cold symptoms or that it serves as a preventive therapy if given before developing respiratory infection.
“Those considering zinc as a cold treatment should be aware of the limited evidence base and potential side effects.” [problemas intestinales, náuseas y sabor desagradable]”Daryl Nault, professor of Integrative Health at the University of Maryland and author of the review, then warned. In a comment to the portal Science Media CenterHarri Hemilä, researcher at the Department of Public Health at the University of Helsinki (Finland) and expert in the study of zinc in colds, assured that zinc is effective and criticized that the Cochrane review does not take into account the doses or the type of pill: “The review does not separate the pills [que se disuelven en la boca] of normal tablets, which is an obvious mistake. “Studies with pills have shown benefits, but not studies with ordinary tablets,” he stressed.
The US National Institutes of Health also notes that the results of clinical trials with zinc supplements have been “inconsistent,” but, “in general, supplemental zinc in pill or syrup form appears to reduce the duration, but not the severity, of the signs and symptoms of the common cold when taken soon after a person develops a cold.”
Garlic and probiotics
This is not the first time that the Cochrane network has reviewed the evidence on potential remedies for the common cold. Another investigation in 2020 concluded that there is not enough evidence to confirm that garlic, which is attributed antimicrobial and antiviral properties, serves to prevent or treat colds. On the effect of plant preparations Echinaceaanother 2013 Cochrane analysis also expressed caution about its potential benefits: The authors cautioned that consumers need to be aware that products under this name differ greatly and most have not been tested in clinical trials. The research found “hints” of its potential benefits in adults, but the evidence for effects was weak: “Our exploratory meta-analyses suggest that at least some preparations of echinacea may reduce the relative risk of contracting a cold by 10% to 20%. %. A 15% risk reduction would mean that if 500 out of every 1,000 people given a placebo get a cold, this figure would be 425 out of every 1,000 people given an echinacea product. This is clearly a small effect of unclear clinical relevance. Furthermore, we cannot say which echinacea products have an effect of this magnitude, or a larger or smaller effect,” the authors explained. The American Association of Family Physicians (AAFP), for its part, considers that it is no more effective than placebo in reducing the duration or severity of symptoms.
There were also Cochrane researchers who analyzed the level of evidence on the role of probiotics in the common cold and concluded that “they could be beneficial”, but here too more in-depth research is needed to refine the dimension of their effect: according to the authors, these Products, which are made up of live microorganisms that help maintain the balance of the intestinal microbiome, could reduce the number of people diagnosed with three infections of this type by 41% and would have the capacity to reduce the duration of these episodes by just over a day. However, the level of certainty of all these conclusions is limited, they warned.
Regarding vitamin C, the Mayo Clinic warns that this supplement has not been shown to help prevent colds, but it does admit that “some studies have shown that taking vitamin C before cold symptoms begin can shorten the duration of symptoms.” symptoms”. The American Association of Family Physicians, however, calls supplementation with this substance “no more effective than placebo” in reducing the duration of symptoms or severity in adults (in children they do see a small effect over time duration of the clinical picture).
What does work to alleviate—not shorten—cold symptoms in adults, says Molero, are paracetamol, ibuprofen, and combinations of antihistamines and decongestants. And it also helps to stay well hydrated. “All this helps reduce the symptoms, but it does not cure the cold sooner. Vapors, for example, relieve nasal and throat symptoms, but do not shorten the duration of the cold,” he adds. Honey also helps, in adults and children over one year old, to relieve cough (in babies under 12 months it is not recommended due to the risk of botulism).
Childhood colds “heal themselves”
In the field of childhood colds, the AAFP does conclude that analgesics are effective symptomatic treatments for fever-related discomfort and the mucolytic acetylcysteine can reduce cough in children two years of age or older, but it does not recommend any medication for children under four years of age. . The Spanish Association of Pediatrics also does not recommend giving anti-cold medications to the little ones (only anti-pyretics if the fever bothers them a lot) and warns that most of these drugs, in fact, are not authorized for use in children under two years of age. “Colds heal themselves,” the scientific society insists.
Carlos Rodrigo, clinical director of Pediatrics at the Germans Trias i Pujol Hospital in Badalona, assures that “there is nothing to do” for the common cold in children. The doctor admits that, although, sometimes, these symptoms “can be the beginning of something else”, such as the flu, covid or bronchiolitis caused by the respiratory syncytial virus, in most cases it is a process banal and little worrying. “It is so banal that the child is getting immunized. It is not given more importance because it is a benign infection. It’s annoying, but nothing more,” he says.
What the consulted experts do agree on is that nasal irrigation with saline relieves nasal congestion. “Nasal washes have been given a lot of thought. Whey, which is water with salt in very low concentrations, is used to help dissolve the mucus. It does not serve to cure or prevent infections, but it cleans and unclogs,” says Rodrigo.
In this sense, last month, during the European Respiratory Society Congress, a group of British researchers presented the results of research in which they suggested that a hypertonic saline solution administered through nasal drops can reduce the duration of a cold in children. “We found that children using saltwater nose drops had cold symptoms for an average of six days, while those receiving usual care had symptoms for eight days. “Children who received salt water nasal drops also needed less medication,” explained Steve Cunningham, from the University of Edinburgh, in a statement from the scientific society.
“Salt is made up of sodium and chloride. Chloride is used by the cells that line the nose and tracheas to produce hypochlorous acid within the cells, which they use to defend against viral infection. By giving extra chloride to the lining cells, this helps the cells produce more hypochlorous acid, which helps suppress viral replication, reducing the duration of viral infection and therefore the duration of symptoms,” he justified. The study, however, has not yet been published in any scientific journal.
Martín de Vicente agrees, with all the precautions and waiting to know it in depth and validate the data in other research, that it is a “quite interesting and promising” study: “It is cheap and provides a possible preventive benefit because those who used it had lower frequency of wheezing. It can be a protective agent for possible complications such as bronchitis,” he values. Rodrigo, for his part, considers that it is a “solid” research group, but is cautious: “Instead of using saline, they have added a higher concentration of salt to help dissolve the mucus. But I still find it surprising that it reduces the duration of the cold and the contagiousness. Serum and saline solutions are not known to have antiviral effects.”