For those of us in colder climates, many of us have already battled the common cold this season. Though generally not a serious illness for those who’re otherwise healthy, the common cold can be a nuisance.
Keep reading to find out some natural cold remedies that have been evaluated in randomized controlled trials.
What Are the Symptoms of the Common Cold?
Typically symptoms of the common cold include: sore throat, cough, sneezing, running nose, headache, fatigue, and a low-grade fever. The symptoms of the common cold tend to last for around a week.
How Do You Get Sick?
Since colds are caused by more than 100 different viruses, antibiotics are ineffective for treating the common cold though physicians sometimes prescribe them to treat secondary bacterial infections (bronchitis, pneumonia).
Tips to Prevent Catching a Cold?
Though there’s no 100% reliable way of preventing colds, you can reduce your risk by washing your hands regularly, eating plenty of fruits and vegetables, getting regular exercise, sleep, and limiting your stress levels. In addition to these common measures, there’s also some herbs and vitamins that may also be effective natural cold remedies.
Lifestyle Treatments for the Common Cold:
- Make sure that you drink plenty of water to stay hydrated and to loosen mucus
- Hot beverages – studies suggest that hot beverages can help to temporarily relieve some of the symptoms of colds such as sore throat, cough, and runny nose.
- Get plenty of rest – It’s important to avoid complications and to restore your energy levels.
- Continue to eat plenty of fruits and vegetables to maintain a healthy diet.
Natural or Herbal Remedies for the Common Cold
Grade: A (Strong Scientific Evidence)
1. Wash your hands frequently
Washing your hands obviously won’t help cure your cold, but frequent hand washing serves two purposes–If you’re already sick, it prevents you from spreading the cold virus to others and if you’re not then it helps reduce your risk of catching a cold.
2. Andrographis paniculata
Unlike Zinc nasal swabs, Andrographis is an herbal remedy that I would recommend. In the past, I formulated a cold and flu product that contained Andrographis in addition to other ingredients. I’ve personally tried andrographis as well and found it to be effective at reducing nasal congestion and sneezing, in particular.
Andrographis when combined with Siberian Ginseng (Eleutherococcus senticosus) has been shown to reduce cold symptoms in one study. As well, another study found that it reduced symptoms and complications in those with influenza infections.
- Dose: a 300 mg Kan Jang® tablet conaining 40-60 mg of andrographolide constituents taken 4 times per day (4x 300 mg tablets).
Grade: B (Fair to Good Scientific Evidence)
1. Vitamin C
Vitamin C has long been regarded as a potential cure for the common cold. Nobel Prize Winner, Linus Pauling, first extolled the benefits of mega dose supplementation with vitamin C. However, the current evidence that vitamin C can cure the common cold is lacking.
Despite this, there are some studies that suggest that vitamin C supplementation may be beneficial for reducing the duration of colds (about a day) and also preventing colds  in athletes exposed to extreme environments (such as cross-country skiers).
2. Probiotics (lactobacillus)
Some preliminary studies suggest that probiotics containing lactobacillus strains may be beneficial in preventing people from acquiring the common cold and may also reduce the severity of cold symptoms in children [3,4].
3. N-acetyl cysteine – NAC
N-acetyl cysteine is a potent antioxidant that has been used for several years to treat various lung conditions such as bronchitis due to its expectorant or mucolytic properties.
In one study, the researchers found that daily supplementation with 600 mg n-acetyl cysteine tablets reduced the infection rate of influenza like symptoms as well as severity of symptoms in elderly patients.
Echinacea has been a somewhat controversial herb used to prevent and treat symptoms of the common cold. Evidence for the efficacy of Echinacea purpera (typical dose of 300 mg take 3 times per day) tends to oscillate back and forth between being effective and ineffective. Overall, it appears that there’s some evidence that Echinacea may be effective .
7. Garlic (Allium Sativa)
Garlic’s long been known to have some antimicrobial properties. One study found that regular supplementation with garlic capsules reduced the risk of catching the common cold. Data from this study is limited, of course.
If you’re considering taking garlic supplements, keep in mind a few things. First, they can cause garlic breath which is unpleasant. Secondly, garlic supplements should be avoided in those who take blood-thinners since it can increase your risk of bleeding.
8. Vitamin D
Research suggests that low levels of vitamin D are associated with an increased risk of upper respiratory infections . In fact, declining levels of vitamin D during the winter months is one of the recent hypothesis for the increasing incidence of colds and the flu during winter months .
Recently, vitamin D recommendations have increased to 600 IU/day for most Adults and 800 IU/day for the elderly (follow the link for more details).
9. Elderberry (Sambucus Nigra)
Elderberry has been studied for its potential role in shortening the duration of the flu. As well, it potentially helps with lessening congestion.
Grade c: (Unclear or Conflicting Evidence)
Though zinc is required for your immune system to function properly, the clinical trial data supporting the use of zinc (lozenges or nasal sprays) is unreliable at best. What’s more is that large doses of zinc (>50 mg/d over a long period) can be dangerous.
Zicam®, a popular cold remedy which contains zinc, has settled lawsuits in the past from people complaining that they lost their sense of smell (anosmia) from the use of various Zicam® nasal swabs and gels (containing zinc).
2. Siberian Ginseng – Eleutherococcus senticosus
Both Siberian and American Ginseng are often referred to as ‘adaptogens’ with putative benefits in adapting to stress. As above, Siberian Ginseng has been studied in combination with Andrographis – one study showed that when taken within 72 hours of the onset of a cold, the combination was effective at significantly improving the symptoms of the common cold.
3. American Ginseng – Panax quinquefolium
There’s at least some evidence that doses of 400 mg per day of American Ginseng may reduce both the risk of catching the cold as well as reducing the severity of symptoms.
If you like spending money, you can go out and buy some ColdFx® which simply contains panax quinquefolium. Nothing more. Though their marketing slogan is “Stops cold and flu in its tracks” and they additionally claim that it “strengthens the immune system,” the clinical trial data they provide is of dubious value at best. The problems with the methodology of their widely touted studies has been critiqued in a the journal, Canadian Family Physician: Does Cold-Fx work?:
- There are no published data with clinical end points using COLD-fX for the treatment of cold and flu.
- When taken for 4 months to prevent colds and flu, COLD-fX might decrease the number of colds by 0.25 colds/person among adults who had had more than 2 colds in the previous year. However, the clinical relevance of this decrease is unknown.
- At this time, data are insufficient to recommend the routine use of COLD-fX.
Though not particularly well studied compared to some of the other herbal options, there was a fairly recent study that found astragulus was beneficial in improving symptoms of rhinorrhea in patients with seasonal allergic rhinitis .
Dose: 80 mg of Astragalus membranaceus (AM) root extract as an active ingredient per capsule – standardized to contain 40% of polysaccharides. 2 capsules two times per day (in the study cited above).
5. Chamomile –
continue reading to find out if Cold-Fx actually works…
Does Cold-Fx Work?
As above, Cold-Fx is a product used by thousands of Canadians during the winter months. Why wouldn’t you take something that’s relatively safe that’s widely touted to strengthen your immune system and stop the cold and flu in its tracks? After all, it is clinically proven after all, right?
Well, there’s science and then there’s this…
Study 1: Cold-Fx in Community dwelling seniors
Let’s take a look at the first publication (McElhaney JE et al, 2006). Basically, this study included 43 volunteers over the age of 65 who were randomized to either placebo or Cold-Fx during the winter months in Edmonton (read flu season). Of note, the Journal of Complementary and Alternative medicine in which this study was published, is widely regarded of questionable quality.
In terms of group characteristics, the Cold-Fx group had a male: female ratio of 8:13 vs. 13:9 in the placebo group, so the Cold-fx group was largely comprised of men vs. the placebo group which was largely comprised of women.
Next, the subjects randomized to take Cold-Fx or placebo were to do so for a duration of 4 months. After the first month both groups were given the flu vaccine.
All outcome measures were based on self-reported symptoms and subject to recall bias. Further, because the patients neither visited a doctor nor had any laboratory tests, there’s really no way of knowing whether or not they had the common cold or the flu.
Despite these metholodological limitations, there were no differences between Cold-Fx users and placebo after 2 months.
“During this second half of the study, COLD-fX treatment reduced the relative risk of respiratory symptoms by 48%.”
During the first half of the study, there was actually more reported respiratory tract illness (not statistically significant) among Cold-Fx users. What’s more is that relative risk is statistic often used to sensationalize data to make it sound significant. As well, they conveniently disregarded the first 2 months of their own study data to make the above statement. If you include the data for the first two months of their study, by my calculation the absolute risk reduction is about 9% among Cold-Fx users and not likely statistically significant.
Why is relative risk misleading?
“Relative risk appears to be a mechanism used to exaggerate differences between two groups. Obviously, a 100% increased (relative) risk is far more startling than a 0.1% increase in (absolute) risk…”
Frequency of Adverse events related to acute respiratory tract illness
|4 weeks treatment||9||12||1.13||NS|
|8 weeks (1 month post vaccination||6||2||2.23||NS|
|16 weeks treatment||7||13||3.91||<0.05|
You don’t need a PhD in statistics to see that claiming that Cold-Fx reducing the relative risk of acute respiratory tract illness by 48% compared to placebo is just a blatant misrepresentation of the above data.
Study 2: Efficacy of Cold-Fx in preventing upper respiratory tract infections in adults (18-65)
The second study for Cold-Fx (Predy GN, et al, 2005) attempted to look at the efficacy of Cold-Fx in preventing upper respiratory tract infections.
Inclusion criteria: Volunteers must have had 2 or more colds in the previous year. Those who had an influenza vaccine in the past 6 months were excluded.
Indeed, the study found that over the 4 month duration of their study, there were 0.25 fewer colds per person in the Cold-Fx group. Naturally, the clinical significance of this is uncertain.
There were no statistically significant differences between groups in terms of the proportion of users who experienced at least one cold.
Nor were there any differences in the duration of each cold between either group.
12% more people in the placebo group reported having more than one cold compared to the Cold-Fx group.
Published commentary on this study’s methodology:
“However, there were also flaws in this study: reliance on self-reporting of symptoms, the Jackson cold definition was modified and used in a non-validated manner, and no laboratory data were collected. Without diagnostic confirmation from the laboratory, it was unknown whether patients had the common cold or influenza because patients were at risk for both; this further invalidates the chosen scoring system, because the Jackson score was developed using a rhinovirus challenge (ie, for colds, not flu). In addition, even if the scoring system were valid, the clinical relevance of this difference of 0.25 fewer colds per person over 4 months is unknown.”
The bottom line is that the evidence for herbal supplements or natural remedies for preventing and treating the common cold and flu are not yet entirely conclusive.
Personally, I get a yearly flu vaccine and I take 2000 IU of vitamin D during the winter months since I live in a cold climate. In addition to lifestyle interventions and other common measures, regular supplementation with Vitamin C (though not a mega doses) along with taking Andrographis (if you can find a reliable source).
Summary of Recommended Natural Cold Remedies
- Wash your hands frequently
- Vitamin C
- Vitamin D
- Andrographis paniculata
- Mkrtchyan A, Panosyan V, Panossian A, Wikman G, Wagner HPhytomedicine. A phase I clinical study of Andrographis paniculata fixed combination Kan Jang versus ginseng and valerian on the semen quality of healthy male subjects. 2005 Jun;12(6-7):403-9.
- Examining the evidence for the use of vitamin C in the prophylaxis and treatment of the common cold.
- Randomised, double-blind and placebo-controlled study using new probiotic lactobacilli for strengthening the body immune defence against viral infections.
- Probiotic effects on cold and influenza-like symptom incidence and duration in children.
- Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey.
- Arch Intern Med. 2009 Feb 23;169(4):384-90.
- Serum 25-hydroxyvitamin d and the incidence of acute viral respiratory tract infections in healthy adults.
- McElhaney JE, Goel V, Toane B, Hooten J, Shan JJ. Efficacy of COLD-fX in the prevention of respiratory symptoms in community-dwelling adults: a randomized, double-blinded, placebo controlled trial. J Altern Complement Med. 2006 Mar;12(2):153-7.
- Predy GN, Goel V, Lovlin R, Donner A, Stitt L, Basu TK. Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial. CMAJ. 2005 Oct 25;173(9):1043-8.
Matkovic Z, Zivkovic V, Korica M, Plavec D, Pecanic S, Tudoric N.
Efficacy and safety of Astragalus membranaceus in the treatment of patients with seasonal allergic rhinitis. Phytother Res. 2010 Feb;24(2):175-81. doi: 10.1002/ptr.2877.