By Matt Gowan, BSC, ND
March 17, 2017

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Home Remedies for Colds and Flu

By Matt Gowan, BSC, ND
March 17, 2017

There are lots of home remedies for colds and flu but do they actually work?  You might be surprised to learn that there is some research to support them. Next time you get a sore throat and stuffy nose, check your fridge or spice cabinet for some of these home remedies the help fight the common cold or flu.

Black and Green Tea

Gargle with tea for colds and flu

Cup of Green Tea

Tea is at the top of my list of home remedies for colds and flu because it can be found in almost every household around the world. Furthermore, it has some good research to support its antiviral activity. Gargling with tea helps to prevent influenza infection.1–4 In fact, those who gargle tea are about 30% less likely to get the flu compared to those who gargle water5,6.   Also taking green tea orally appears to reduce cold and flu symptoms7.

How does tea help a cold?

Tea, especially green tea, contains polyphenols (e.g. catechins, EGCG) that inhibit the growth and activity of several viruses that cause respiratory tract infections including influenza virus8–13, enterovirus14 and adenovirus15.  Catechins interfere with the viral infection by blocking viral entry into cells16 and replication14,16–23.  Moreover, they reduce free radical damage produced by the infection14,19.  Tea also helps the body combat the infection by regulating the immune response by stimulating the production of interferon24,25 (IFN-gamma, IFN-alpha), and decreasing expression of inflammatory cytokines (IL-6) that elicits harmful effects on the body18 . EGCG also decreases the risk of mortality and pathological lesions 26 and overcomes drug resistance-related mutations27.

How do I take tea?

Both gargling with tea and drinking it helps both prevent and improve cold symptoms.

  • Drink 1-5 cups/day green tea4
  • Capsules: 378 mg capsule/day3
  • Gargle with black or green tea†

†Note: the research used standardized extract os 200 mcg/ml catechin (60% EGCG) or  0.5% w/v black tea extract1,2

How safe is tea?

Tea is very safe however it contain caffeine that in high amount can be over-stimulating and cause increased heart rate and insomnia.

Ginger

Ginger - Home remedy to help colds

Ginger rhizome

Ginger rhizome (inaccurately referred to as the “root”) grows in tropical climates and is used around the world as a culinary spice and medicinal herb.  In medicine, ginger is used primarily to help relieve nausea and improve digestion but it also has benefits for the respiratory tract. In Chinese medicine, it is used to thin mucous and relieve coughs28.  Most people have fresh ginger in their fridge or dried powder in their spice cabinet making it second on my list of home remedies for colds and flu.

How does ginger work?

Ginger inhibits the activity of viruses that cause colds and flu, including RSV29,30 and rhinovirus31. It also helps the body fight off infections by activating specific white blood cells (macrophages) with subsequent production of TNF-alpha32 that stimulates the immune system.  Although human studies are lacking, the preliminary data does appear to support the traditional use of ginger for respiratory tract infection.  Regardless ginger tea tastes good and there’s no harm taking it, so why not give it a try?

How do I take ginger?

Both fresh and dried ginger can be used.  Ideally, boil a pot of water and add the desired amount of ginger.  Cover and let it simmer for 5-15 minutes to get the maximum extraction of the active ingredients.

• Dried root: 3-9 g28 (roughly 1-2 tsp per cup)
• Fresh root: ½-1 tbsp per cup

How safe is it?

Ginger is very safe and well-tolerated in most people. In addition, it is safe to take during pregnancy33.

Caution: It may cause heartburn in some people, especially if you drink the tea and lay down immediately. Do not take ginger if you are taking blood-thinning medication without speaking to your naturopathic doctor.

Chicken Soup 

As a kid, you were probably given chicken soup when you were sick.  It turns out it probably did make you feel better!  Research supports this home remedy because it provides relieve of cold symptoms34.

Chicken soup - The most common home remedies for colds and flu

Chicken soup

How does it work?

Chicken soup decreases inflammation by reducing the migration of certain white blood cells (neutrophils)35.  Over stimulation of neutrophils leads to increase inflammation and damage to the airways that result in symptoms.  Moreover, adding vegetables that are rich in antioxidants (including celery, onion, carrots, parsley) may also be beneficial for fighting off infection34.

How do I take it?

Just eat a bowl or two of the soup.  Preferably chicken soup that is home-made and also contains vegetables.

How safe is it?

Chicken soup is very safe, providing you don’t spill it and burn yourself.

Garlic

Garlic - Antiviral home remedy for colds and flu

Garlic

Garlic is used in herbal medicine to help fight infection.  Garlic supplementation led to a decrease in common cold incidence and shorter duration of symptoms36 and also reduces cold and flu severity37.  Moreover, a significant reduction in the number of symptoms, the number of days of illness and incidence of cold and flu was observed in patients a garlic supplement38.

How does it work?

Garlic has some direct antiviral effects and it also enhances immune cell function leading to a decrease in colds and flu severity 37. The extract also exhibits anti-viral effects against rhinovirus, an organism that is also responsible for common colds39.

How do I take it?

High heat destroys the active compounds. Crush a clove of fresh garlic and try to eating raw for best results.  You can also buy a garlic supplement if you want to avoid the strong taste and odor.

 How safe is it?

Garlic is generally safe but can upset some people’s stomach.  Side-effect also includes rash and odour40.

Caution: Do not take garlic if you are taking blood thinners without speaking to your naturopathic doctor.

Honey

Honey possess remarkable healing properties. It has been used for thousands of years to fight infections and promote the healing
of wounds, burns, and ulcers.  Drinking hot lemon water with honey is a common home remedy for colds to help soothe a sore throat and cough.   Research shows that honey reduces symptoms of common colds in children41.  Moreover, honey acts as a cough suppressant and can help provide relief for a stubborn cough42–45.

Honey - Home remedy for colds and flu

Honey

How does honey work?

Honey is rich in phytochemicals called flavonoids.  Research shows flavonoids, like quercetin, activate white blood cells (macrophages) that help the body fight off infections46. In additon, they inhibit the replication of cold viruses including RSV47,48  and rhinovirus49,50.  Honey possess antiviral activity and specifically inhibits influenza virus replication51.

How do I take honey?

Try taking a spoonful of honey a few times a day.

How safe is honey?

Honey is safe for the most part but contains high amounts of sugars.  Small amounts of honey can be good for you but too much sugar is bad for the immune system.  Limit the amount you take per day to 2-3 teaspoons.

Caution. Honey should not be given to children under the age of two years old. Infants lack the digestive function to destroy the botulism spores and are at increased risk of botulism52.  

Steam inhalation with Eucalyptus oil to reduce congestion

Eucalyptus tree

Steam inhalation with essential oils is a common home remedy for colds to help loosen phlegm. Essential oils have some antibacterial and antiviral properties. Eucalyptus oil is the most popular choice for steam inhalation because of its agreeable smell and medicinal properties.  Herbalists recommend it as an expectorant53 to help loosen and cough up phlegm.  Although steam inhalation may have some benefit and can cause burns (See below) so be careful!

How does it work?

Essential oils disrupt the cell membranes of viruses.  Studies show eucalyptus oil exerts antiviral activity against several strains of viruses that cause respiratory tract infections54.  In addition, it appears to possess some anti-inflammatory properties that may help relieve symptoms55.

Steam inhalation with eucalyptus oil has been recommended as a home remedy for colds but only a few studies supported this claim56–59.  In theory, inhaling water vapor should help dissolve sticky phlegm and make it easier to cough up.  However, newer studies conclude that steam inhalation alone does not have a significant impact on the severity of cold symptoms.   So the verdict is still out on steam inhalation alone but combining the eucalyptus oil should help.

How do I do it?

Steam inhalation must be done with care to avoid burns.

Adults: Boil water and add 10-15 drops of eucalyptus oil.  Cover with a towel and allow the water to cool down a bit.  Carefully lift one corner of the towel and allow some of the steam to escape.  Test the temperature to make certain it won’t burn.  Slowly inhale the steam allowing ambient air to mix with it to cool it to the appropriate temperature.  Repeat the cycle a few times.

Children: To reduce the risk of burns, modify the approach for kids.  Add hot water to a face cloth.  Sprinkle 3-5 drops of eucalyptus oil to the cloth.  Make sure the temperature is not too hot. Place over the mouth and breathe deeply.  Repeat cycle several times.  You can reheat the cloth in the microwave and reapply eucalyptus as needed.

How safe is steam inhalation with eucalyptus oil?

Although steam inhalation is a common home remedy for colds it does have some serious safety concerns. When done correctly steam inhalation causes only minor issues including discomfort and nasal irritation.

Eucalyptus oil is very potent and should not be consumed orally.  Avoid exposing the eyes and sensitive skin steam and essential oils.

Caution: Steam inhalation can cause serious burns!  Numerous cases of people burning themselves have been reported60. Never allow children to do this without proper supervision. 

Are Home Remedies for Colds and Flu the most effective treatment?

Although the above home remedies for colds and flu are useful there are more effective natural treatments.  Numerous herbs and supplements can help both prevent and treat colds and flu, however, these are not usually found in the average household.  If you’re interested in learning more about these treatments read my blog on Natural Treatments for Colds and Flu.

Author & Photographer: Matt Gowan, BSc, ND
All images are copyright of Matt Gowan ©2017

Disclaimer: This content is subject to change. The information is intended to inform and educate; it does not replace the medical evaluation, advice, diagnosis or treatment by a healthcare professional. www.nhpassist.com © 2017 NDAssist Inc. and/or its affiliates. All rights reserved.
1.
Iwata M, Toda M, Nakayama M, et al. [Prophylactic effect of black tea extract as gargle against influenza]. Kansenshogaku Zasshi. 1997;71(6):487-494. [PubMed]
2.
Yamada H, Takuma N, Daimon T, Hara Y. Gargling with tea catechin extracts for the prevention of influenza infection in elderly nursing home residents: a prospective clinical study. J Altern Complement Med. 2006;12(7):669-672. [PubMed]
3.
Matsumoto K, Yamada H, Takuma N, Niino H, Sagesaka Y. Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: a randomized controlled trial. BMC Complement Altern Med. 2011;11:15. [PubMed]
4.
Park M, Yamada H, Matsushita K, et al. Green tea consumption is inversely associated with the incidence of influenza infection among schoolchildren in a tea plantation area of Japan. J Nutr. 2011;141(10):1862-1870. [PubMed]
5.
Ide K, Yamada H, Kawasaki Y. Effect of gargling with tea and ingredients of tea on the prevention of influenza infection: a meta-analysis. BMC Public Health. 2016;16:396. [PubMed]
6.
Ide K, Kawasaki Y, Akutagawa M, Yamada H. Effects of Green Tea Gargling on the Prevention of Influenza Infection: An Analysis Using Bayesian Approaches. J Altern Complement Med. 2017;23(2):116-120. [PubMed]
7.
Rowe C, Nantz M, Bukowski J, Percival S. Specific formulation of Camellia sinensis prevents cold and flu symptoms and enhances gamma,delta T cell function: a randomized, double-blind, placebo-controlled study. J Am Coll Nutr. 2007;26(5):445-452. [PubMed]
8.
Nakayama M, Toda M, Okubo S, Hara Y, Shimamura T. [Inhibition of the infectivity of influenza virus by black tea extract]. Kansenshogaku Zasshi. 1994;68(7):824-829. [PubMed]
9.
Nakayama M, Suzuki K, Toda M, Okubo S, Hara Y, Shimamura T. Inhibition of the infectivity of influenza virus by tea polyphenols. Antiviral Res. 1993;21(4):289-299. [PubMed]
10.
Imanishi N, Tuji Y, Katada Y, et al. Additional inhibitory effect of tea extract on the growth of influenza A and B viruses in MDCK cells. Microbiol Immunol. 2002;46(7):491-494. [PubMed]
11.
Kuzuhara T, Iwai Y, Takahashi H, Hatakeyama D, Echigo N. Green tea catechins inhibit the endonuclease activity of influenza A virus RNA polymerase. PLoS Curr. 2009;1:RRN1052. [PubMed]
12.
Shin W, Kim Y, Lee K, Seong B. Evaluation of the antiviral activity of a green tea solution as a hand-wash disinfectant. Biosci Biotechnol Biochem. 2012;76(3):581-584. [PubMed]
13.
Yang Z, Bai L, Huang W, et al. Comparison of in vitro antiviral activity of tea polyphenols against influenza A and B viruses and structure-activity relationship analysis. Fitoterapia. 2014;93:47-53. [PubMed]
14.
Ho H, Cheng M, Weng S, Leu Y, Chiu D. Antiviral effect of epigallocatechin gallate on enterovirus 71. J Agric Food Chem. 2009;57(14):6140-6147. [PubMed]
15.
Weber J, Ruzindana-Umunyana A, Imbeault L, Sircar S. Inhibition of adenovirus infection and adenain by green tea catechins. Antiviral Res. 2003;58(2):167-173. [PubMed]
16.
Kesic M, Simmons S, Bauer R, Jaspers I. Nrf2 expression modifies influenza A entry and replication in nasal epithelial cells. Free Radic Biol Med. 2011;51(2):444-453. [PubMed]
17.
Song J, Lee K, Seong B. Antiviral effect of catechins in green tea on influenza virus. Antiviral Res. 2005;68(2):66-74. [PubMed]
18.
Zu M, Yang F, Zhou W, Liu A, Du G, Zheng L. In vitro anti-influenza virus and anti-inflammatory activities of theaflavin derivatives. Antiviral Res. 2012;94(3):217-224. [PubMed]
19.
Ling J, Wei F, Li N, et al. Amelioration of influenza virus-induced reactive oxygen species formation by epigallocatechin gallate derived from green tea. Acta Pharmacol Sin. 2012;33(12):1533-1541. [PubMed]
20.
Kim M, Kim S, Lee H, et al. Inhibition of influenza virus internalization by (-)-epigallocatechin-3-gallate. Antiviral Res. 2013;100(2):460-472. [PubMed]
21.
Müller P, Downard K. Catechin inhibition of influenza neuraminidase and its molecular basis with mass spectrometry. J Pharm Biomed Anal. 2015;111:222-230. [PubMed]
22.
Baatartsogt T, Bui V, Trinh D, et al. High antiviral effects of hibiscus tea extract on the H5 subtypes of low and highly pathogenic avian influenza viruses. J Vet Med Sci. 2016;78(9):1405-1411. [PubMed]
23.
Karimi A, Moradi M, Alidadi S, Hashemi L. Anti-adenovirus activity, antioxidant potential, and phenolic content of black tea (Camellia sinensis Kuntze) extract. J Complement Integr Med. 2016;13(4):357-363. [PubMed]
24.
Monobe M, Ogino A, Ema K, Tokuda Y, Maeda-Yamamoto M. A crude extract from immature green tea (Camellia sinensis) leaves promotes Toll-like receptor 7-mediated interferon-α production in human macrophage-like cells. Cytotechnology. 2012;64(2):145-148. [PubMed]
25.
Hu X, Shao M, Song X, et al. Anti-influenza virus effects of crude phenylethanoid glycosides isolated from ligustrum purpurascens via inducing endogenous interferon-γ. J Ethnopharmacol. 2016;179:128-136. [PubMed]
26.
Xiao X, Yang Z, Shi L, Liu J, Chen W. [Antiviral effect of epigallocatechin gallate (EGCG) on influenza A virus]. Zhongguo Zhong Yao Za Zhi. 2008;33(22):2678-2682. [PubMed]
27.
Ide K, Kawasaki Y, Kawakami K, Yamada H. Anti-influenza Virus Effects of Catechins: A Molecular and Clinical Review. Curr Med Chem. 2016;23(42):4773-4783. [PubMed]
28.
Bensky D, Gamble A. Chinese Herbal Medicine – Materia Medica. 3rd ed. Seattle, WA: Eastland Press Inc.; 2004.
29.
Chang J, Wang K, Yeh C, Shieh D, Chiang L. Fresh ginger (Zingiber officinale) has anti-viral activity against human respiratory syncytial virus in human respiratory tract cell lines. J Ethnopharmacol. 2013;145(1):146-151. [PubMed]
30.
Yang X, Li C, Huang C. Curcumin modified silver nanoparticles for highly efficient inhibition of respiratory syncytial virus infection. Nanoscale. 2016;8(5):3040-3048. [PubMed]
31.
Denyer C, Jackson P, Loakes D, Ellis M, Young D. Isolation of antirhinoviral sesquiterpenes from ginger (Zingiber officinale). J Nat Prod. 1994;57(5):658-662. [PubMed]
32.
Imanishi N, Andoh T, Mantani N, et al. Macrophage-mediated inhibitory effect of Zingiber officinale Rosc, a traditional oriental herbal medicine, on the growth of influenza A/Aichi/2/68 virus. Am J Chin Med. 2006;34(1):157-169. [PubMed]
33.
Mills E, Dugoua J, Perri D, Koren G. Herbal Medicines in Pregnancy and Lactation – An Evidence-Based Approach. 1st ed. UK: Taylor & Francis Group; 2005.
34.
Hopkins A. Chicken soup cure may not be a myth. Nurse Pract. 2003;28(6):16. [PubMed]
35.
Rennard B, Ertl R, Gossman G, Robbins R, Rennard S. Chicken soup inhibits neutrophil chemotaxis in vitro. Chest. 2000;118(4):1150-1157. [PubMed]
36.
Josling P. Preventing the common cold with a garlic supplement: a double-blind, placebo-controlled survey. Adv Ther. 2001;18(4):189-193. [PubMed]
37.
Percival S. Aged Garlic Extract Modifies Human Immunity. J Nutr. 2016;146(2):433S-436S. [PubMed]
38.
Nantz M, Rowe C, Muller C, Creasy R, Stanilka J, Percival S. Supplementation with aged garlic extract improves both NK and γδ-T cell function and reduces the severity of cold and flu symptoms: a randomized, double-blind, placebo-controlled nutrition intervention. Clin Nutr. 2012;31(3):337-344. [PubMed]
39.
Weber N, Andersen D, North J, Murray B, Lawson L, Hughes B. In vitro virucidal effects of Allium sativum (garlic) extract and compounds. Planta Med. 1992;58(5):417-423. [PubMed]
40.
Lissiman E, Bhasale A, Cohen M. Garlic for the common cold. Cochrane Database Syst Rev. 2009;(3):CD006206. [PubMed]
41.
Waris A, Macharia M, Njeru E, Essajee F. RANDOMISED DOUBLE BLIND STUDY TO COMPARE EFFECTIVENESS OF HONEY, SALBUTAMOL AND PLACEBO IN TREATMENT OF COUGH IN CHILDREN WITH COMMON COLD. East Afr Med J. 2014;91(2):50-56. [PubMed]
42.
Shadkam M, Mozaffari-Khosravi H, Mozayan M. A comparison of the effect of honey, dextromethorphan, and diphenhydramine on nightly cough and sleep quality in children and their parents. J Altern Complement Med. 2010;16(7):787-793. [PubMed]
43.
Cohen H, Rozen J, Kristal H, et al. Effect of honey on nocturnal cough and sleep quality: a double-blind, randomized, placebo-controlled study. Pediatrics. 2012;130(3):465-471. [PubMed]
44.
Ahmed N, Sutcliffe A, Tipper C. Feasibility study: honey for treatment of cough in children. Pediatr Rep. 2013;5(2):31-34. [PubMed]
45.
Ayazi P, Mahyar A, Yousef-Zanjani M, Allami A, Esmailzadehha N, Beyhaghi T. Comparison of the Effect of Two Kinds of Iranian Honey and Diphenhydramine on Nocturnal Cough and the Sleep Quality in Coughing Children and Their Parents. PLoS One. 2017;12(1):e0170277. [PubMed]
46.
Yasui M, Matsushima M, Omura A, et al. The Suppressive Effect of Quercetin on Toll-Like Receptor 7-Mediated Activation in Alveolar Macrophages. Pharmacology. 2015;96(5-6):201-209. [PubMed]
47.
Gomes D, Caruso Í, de A, et al. Experimental evidence and molecular modeling of the interaction between hRSV-NS1 and quercetin. Int J Biol Macromol. 2016;85:40-47. [PubMed]
48.
Teixeira T, Caruso Í, Lopes B, et al. Biophysical characterization of the interaction between M2-1 protein of hRSV and quercetin. Int J Biol Macromol. 2017;95:63-71. [PubMed]
49.
Ganesan S, Faris A, Comstock A, et al. Quercetin inhibits rhinovirus replication in vitro and in vivo. Antiviral Res. 2012;94(3):258-271. [PubMed]
50.
Song J, Park K, Kwon D, Choi H. Anti-human rhinovirus 2 activity and mode of action of quercetin-7-glucoside from Lagerstroemia speciosa. J Med Food. 2013;16(4):274-279. [PubMed]
51.
Watanabe K, Rahmasari R, Matsunaga A, Haruyama T, Kobayashi N. Anti-influenza viral effects of honey in vitro: potent high activity of manuka honey. Arch Med Res. 2014;45(5):359-365. [PubMed]
52.
Grabowski N, Klein G. Microbiology and foodborne pathogens in honey. Crit Rev Food Sci Nutr. 2017;57(9):1852-1862. [PubMed]
53.
Hoffmann D. Medical Herbalism. Healing Arts Press; 2003.
54.
Cermelli C, Fabio A, Fabio G, Quaglio P. Effect of eucalyptus essential oil on respiratory bacteria and viruses. Curr Microbiol. 2008;56(1):89-92. [PubMed]
55.
Juergens U. Anti-inflammatory properties of the monoterpene 1.8-cineole: current evidence for co-medication in inflammatory airway diseases. Drug Res (Stuttg). 2014;64(12):638-646. [PubMed]
56.
Macknin M, Mathew S, Medendorp S. Effect of inhaling heated vapor on symptoms of the common cold. JAMA. 1990;264(8):989-991. [PubMed]
57.
Ophir D, Elad Y. Effects of steam inhalation on nasal patency and nasal symptoms in patients with the common cold. Am J Otolaryngol. 1987;8(3):149-153. [PubMed]
58.
Singh M. Heated, humidified air for the common cold. Cochrane Database Syst Rev. 2004;(2):CD001728. [PubMed]
59.
Singh M. Heated, humidified air for the common cold. Cochrane Database Syst Rev. 2006;(3):CD001728. [PubMed]
60.
Baartmans M, Kerkhof E, Vloemans J, et al. Steam inhalation therapy: severe scalds as an adverse side effect. Br J Gen Pract. 2012;62(600):e473-7. [PubMed]