Although there are very few tools that conventional technomedicine has for fighting viruses like colds and flus, there are many, many medicinal herbs that have antiviral activity and many more that stimulate the immune system to fight the infections ourselves. In this article, I will discuss medicinal herbs and foods that can help us prevent viral infections and hasten our recovery when they do come.
Conventional medicine and the pharmaceutical industry have not yet figured out how to deal effectively with viruses. Science still knows very little about viruses. There are some drugs can inhibit replication of certain viruses such as HIV and herpes (having different levels of effectiveness depending on the virus) and vaccines can stimulate the body to create antibodies to a specific virus so that when you do catch it, the immune system can fight it off much more easily. While humans are still quite ignorant about viruses, plants and fungi have a few hundred million years head start on us in finding solutions to protect themselves from these pathogens! Plants' wisdom is contained in their tissues, which we can learn from and benefit from by consuming them, as all of our ancestors have done for hundreds of thousands of years. Many plants and fungi create antiviral compounds that directly kill viruses.
In general, there are three types of pathogens that we are concerned about when it comes to respiratory infection: bacteria, viruses, and fungi. Viruses are very different from bacteria. There are several categories of viruses and many millions of species, only several thousand of which have been named and studied. Not all viruses are bad, some are commensal or dormant, and we may depend on some of them to help us function normally. Some viruses can even help us fight bacteria and fungi !
There are a few tricky things about viruses that make them hard to kill. Firstly, viruses are extremely tiny compared to other pathogens and structurally very simple - consisting of just DNA or RNA and an outer protein layer called a capsid. Some viruses, like the flu (influenza) have an additional outside lipid bilayer membrane called an envelope, which is similar to what animal cells have (like us). Rhinoviruses, which cause the majority of "colds" (rhino- being Greek for "of the nose"), do not have envelopes. Secondly, science is not really sure if viruses are "alive" or not, since they can't live or replicate outside of a living host, so they have fewer ways to be destroyed or made inert compared to other pathogenic cells that live on their own, like bacteria and fungi. Thirdly, they have incredible structural diversity. And forth, they mutate very rapidly, especially cold viruses, so that our immune systems have to constantly try to figure out how to kill the latest version of the pathogen. You may have caught a cold and successfully fought it off two weeks ago, but by the time it infects 10 more people and comes back to you, its genetic mutations have changed it so much that the body now no longer recognizes it and has to start developing antibodies to it all over again as if it was new! Flu's mutate a little less rapidly, which allows scientists to develop flu vaccines. But flu vaccines have varying levels of efficacy, since multiple strains of influenza cause "the flu". Some years' vaccines have higher accuracy and efficacy than others. Drug developers just choose the most common strains of the flu worldwide the previous year and make a vaccine with it, hoping that the strains haven't mutated much while the vaccine was in development. Then next year, they start all over again with the newly mutated influenza strains. If you want to know more about how viruses replicate and infect us, here's some fun little videos here and here.
The good news is that many herbs have ways to help us fight viruses, either by lending us their own antiviral powers, or by stimulating our immune systems to attack viruses more effectively. Plants are also targeted by viruses, so they've learned how to fight them off by creating different types of "secondary metabolites", a fancy term meaning chemical constituents that have a specific biological purpose and that stimulate a physical reaction in the human body. Plants and humans (and our pre-human ancestors) have been co-evolving for a few million years. We have always had medicinal plants as part of our daily lives all throughout our evolutionary history, that is, up until modernity wiped all of them away and replaced them with chemical drugs. I think of medicinal plants as part of the human immune system, just a part that lives outside of our body instead of inside of it. I mean, why go through the trouble of developing your own internal human-version of antiviral compounds when you've got plants all around you to help you out? Well, that is, until modernity reduced our cohabitation with wild plants. (Sigh.) All animals use herbal medicine - there is documentation of cats, dogs, bears, primates, and many other mammals knowing specific plants to take in specific health situations. Even caterpillars do it !
First I will talk about the herbs that are helpful when you feel the virus coming on or when you're in the midst of an infection. These herbs are for short term use and generally need to be taken in high doses frequently, every few hours (to inhibit viral replication, which can take only a few hours). It is especially important to start these herbs as early as possible and continue them until the symptoms are completely gone (and sometimes for a day or two afterward just to be safe). Antiviral herbs work best when taken as soon as you feel the first "tickle". With colds, people who catch the virus may not develop symptoms until 1-2 days later (this is called the incubation period), but they are still contagious during this time as well as for 1-2 days after developing symptoms. This contagious period can be even longer if the person's immune system is weak. Flu's are contagious for longer than colds, sometimes for 7-10 days after catching it. That's why social isolation is very important during the contagious stage, to make sure you don't spread it to other people, especially people with respiratory diseases and compromised immune systems.
Below are a few herbs for acute viral care...
The elder bush or tree (Sambucus canadensis - North American, and Sambucus nigra - European) is used to stimulate the immune system and also as a direct antiviral treatment. It is a very sacred plant that has been used in indigenous European medicine for millennia. The elder berries contain vitamin C and many bioflavonoids, as well as anthocyanidins which are its purple-black pigment. Several clinical trials have shown that elderberry extracts significantly speed up recover from colds and flus, and reduce the need for rescue interventions [3, 4, 5]. Elderberries and flowers also contain anti-inflammatory compounds that reduce the negative consequences of inflammation from innate immune reactions, such as fever, muscle aches, swollen throat and eyes, digestive upset, and so on. Elder flower is used as a diaphoretic, which is an old word that means a plant action that helps the body move and release heat to the periphery of the body, helping a fever break earlier. Elder flowers contain flavonoids such as kaempferol, quercetin, and rutin, which reduce genetic expression of pro-inflammatory interleukins and cytokines. Quercetin in particular is used to reduce the production of histamine, which causes the production of clear, runny mucus that is common in viral infections (and also in allergies).
When in the midst of a viral infection, the adult dose is 1-5 teaspoons of elderberry syrup every 3 hours until the symptoms are gone. This is very easy to do, since elderberry syrup is delicious! Make sure to get syrup made with honey or glycerine, not with sugar or other processed sweeteners. Also, make sure that the elderberries are organic (all herbal medicine should be organic whenever possible, since pesticides are very harmful to the human body and to the environment). You can also make elderberry syrup yourself with dry or fresh berries, though fresh is always better. Elderberries are usually harvested in the late summer or early fall here in Vermont. I get mine from my neighbor who has a bunch of bushes in her backyard, but if you don't have access to local elderberry syrup, I really like the taste of this brand, which is carried in many health food stores in the US. And remember, never buy anything from Amazon.com (they have sketchy business practices, horrible political affiliations, and destroy local, small businesses).
Elder flower is great to be used as a tea during a viral infection, especially if there are fevers and chills. It can help the fever peak and break quick. It's also great for people who can't mount a proper fever, that is, if the fever doesn't get high enough. The ideal temperature for a fever is 101-103° F (38.3 - 39.4° C) for adults, for only a few days at a time. If the temperature gets above that, or if it lasts for more than several days, seek medical attention. Remember, fevers are really important mechanisms that our body uses to fight pathogens! Viruses are destroyed when our body temperature rises and our innate immune system works most efficiently at a higher temperature, so suppressing a fever with tylenol or ibuprofen shuts down this helpful mechanism. That said, if the fever gets too high or lasts too long, we may not want to raise the fever higher, so elder berries and flowers may not want to be used in those situations. Andrographis may be more appropriate (see below).
Fire cider is a traditional European and North American recipe used to fight off acute infections, especially colds and flus. It is an apple cider vinegar infusion of pungent herbs and spices that stimulate the immune system and have direct antiviral effects. The most common herbs used are garlic, ginger, horseradish, turmeric, onion, and a variety of peppers and chilis. It's very easy to make at home as the chopped herbs only need to steep in (organic) apple cider vinegar for 2-4 weeks before being strained and then sweetened to taste with local raw honey.
Pungent and spicy herbs stimulate diaphoresis, as mentioned above, and also thin mucus by encouraging more water secretion from the cells in the mucous membranes of our respiratory tract, sinuses, and gastrointestinal tract. This mucus-thinning effect allows the mucus to be coughed up and cleared out more easily, and it is why pungent herbs are called "expectorants". Garlic is particularly antiviral, as I will mention below, and all of these herbs are anti-inflammatory and can help reduce the achey symptoms of colds and flus. The quercetin contained in onions has been shown to be more effective at killing the flu virus than Tamiflu, the only pharmaceutical treatment for influenza . By stimulating the immune system with expectorants that protect the respiratory tract, recovery from colds and flus can be sped up. A typical dose of fire cider is a 1/2 - 1 ounce (15-30 mL) shot every several hours while symptoms persist. I love to mix fire cider with elderberry syrup to get a sweet and sour flavor! It is usually not available in stores, which is just fine since it's so easy to make yourself and is shelf-stable. There is a nasty company called "Shire City" which unethically trade marked the term "fire cider" (even though it is a term used by folk medicine) and has been suing other companies and organizations using the term. So make sure not to buy fire cider from them.
Garlic is an culinary herb, a food, and a medicine. It is truly a powerful plant that can be used in a hundred applications, all of which I cannot cover here. In particular, this pungent herb is antibacterial, antiviral, antifungal, anticancer, and is anti-inflammatory and protective to the cardiovascular system and the liver. It is one of the strongest antiviral substances known [6,7], and its antiviral compounds (primarily allicin) are readily available in the blood after absorption through the digestive tract. To me, this makes garlic one of the most powerful tools for fighting viral colds and flus.
Multiple constituents in garlic are effective against drug-resistant bacteria such as MRSA [8,9] and make antifungal and antibiotic drugs work better . Studies show that “each clove has from seven to thirteen milligrams of allicin, so three cloves contains the same antibacterial activity as a standard dose of penicillin” . The spiciness of garlic is created by the sulfur-based nutrients called thiosulfinates, which kill cancer cells and reduce the risk of arterial blood clots . Garlic is very high in antioxidants, and will neutralize free radicals quickly and effectively .
During a cold, flu, or respiratory infection of any kind, the optimal dose is 1 clove (raw) every 3 hours. It is very important to crush and chop the clove and then let it sit for 5-10 minutes to let the enzymes activate the antimicrobial constituents (i.e. allicin) that are released from the plant cells when they are broken. Raw garlic can go down easier if you take it with a little honey or a slice of tomato. For people with sensitive stomachs or issues with heartburn, it may be a good idea to take garlic with other food to prevent upset stomach. Once crushed and let sit, garlic can be heated briefly (as you would in a vegetable sauté) without damaging its antimicrobial power too much. But if garlic is "aged" or chopped and then let sit for too long, like 30 min, it will lose most of its antimicrobial effects (but it will still have cardioprotective and anticancer effects). That's why garlic capsules are not antiviral, but they can be helpful in other ways. There is a new supplement called Allimax that claims to have found a way to preserve allicin's effectiveness by protecting it from oxidation (allicin oxidizes very quickly when exposed to air, which neutralizes its effectiveness). To be safe, I just use fresh raw garlic (that my sister grows on her farm). Garlic can also be eaten daily as a tonic and for infection prevention, which may be a really good idea for CFers in general. Make sure your garlic is organic and locally grown if possible. Make sure you do not buy garlic grown in China, as it is often bleached to make it look white!
Allicin and other pungent constituents in garlic are very small, small enough to pass from the blood into the alveolar space in the lungs, where you then breath them out upon exhalation (giving you "garlic breath"). But this is a good thing, because we want those antimicrobial compounds to be working directly on the lung tissue. So if you get garlic breath, that's a good sign that you've taken the right dose! You can also eat fresh parsley or drink wheat grass or barley grass juice to reduce “garlic breath”.
Andrographis paniculata is an herb that comes to us from Ayurvedic medicine, the traditional healing system of India. This extraordinary plant is a powerful antiviral and clinical studies have shown it to be effective in speeding up recovery from colds and flus [13,14]. It is directly antiviral and an excellent stimulant of innate immunity. Andrographis one of my favorite antiviral herbs because it is cooling, unlike most other antiviral and immune-stimulating herbs, which tend to be warming. It is considered a febrifuge, which means that it can directly cool a fever in a way that is different than diaphoretics like elderflower, garlic, ginger, yarrow, etc. I would choose andrographis over elderberry when there is fear that the fever is already too high and should not be increased. It is a very bitter herb, and while tincture is certainly useful it can be too bitter for some adults and most children. Therefore, capsules are usually the easiest way to take them. The typical dose is 1-3 mL of tincture three times per day, or 300-500mg powder (in capsules or tablets with at least 5% standardized andrographolides) three times per day.
Echinacea (E. purpurea, E. angustifolia, or E. pallida) is a well-known herb used to enhance the immune system and fight viruses. It is an immune stimulant, and it is also an excellent lymphatic. A lymphatic is an herb that stimulates the movement of fluid in the lymphatic vessels and the processing of bodily wastes in the lymph nodes. When we are sick, white blood cells that have captured and have begun digesting pathogens move through the lymphatic vessels of the body and collect in the lymph nodes (those lumps under your ears, on your neck, in your arm pits, behind the knees, in the groin, and several other places), the tonsils, and the spleen for processing and break down. Sometimes the body gets overwhelmed by the amount of viral garbage that is being processed, and the lymph nodes can swell and become painful. Echinacea can be helpful for helping the lymph nodes get less backed up and help the lymph flow more smoothly. For this reason, in traditional Native American and European-American medicine, echinacea is used for blood and lymph infections (particularly when there is "streaking" visible on the skin... it's signature is that there is streaking on its flower stem) and venemous snake bites. Lymph movement can be very important in the recovery from flus, as was demonstrated in the 1918 flu pandemic where patients of osteopathic and Eclectic physicians had the highest survival rates because of their manual lymph movement techniques and herbal lymphatic treatments, respectively.
Echinacea contains alkyl-amides and immune active polysaccharides, which are responsible for its immune-stimulating effects. When taken in high doses, several times per day, it is shown to significantly shorten the duration of a cold, and reduce the inflammation and severity of symptoms [15,16]. At lower doses it may not be as effective in acute situations, though it can be helpful for increasing immune vigilance for people with poor immunity on a long-term basis. It is not suitable for people with autoimmune disorders, as it may exacerbate symptoms. The most potent form of echinacea is a tincture of the fresh root. Tincture of fresh flowering tops or dry root is slightly less effective, though still good. Some people like to combine tinctures of fresh tops and fresh roots half and half. A typical dose for colds or acute immune stimulation is 5 mL (1 tsp) every 2 hours as long as the symptoms persist. This can get a little expensive, so I personally prefer to use other herbs instead. But echinacea can be the best choice if the viral infection causes inflamed lymph nodes. Capsules will be less effective since they are made from dry herb (and not all supplements claiming to have echinacea in them actually do, so make sure you choose a good company). It is also traditional to make tea from the dry root.
IMPORTANT: This a very important note on the sustainable use of echinacea. All three echinacea species are native to North America, and Echinacea angustifolia is on the United Plant Savers "At Risk" list (i.e. endangered species) because of overharvesting in the wild. Therefore, do not buy E. angustifolia preparations, especially not if it's wild harvested! Instead, make sure that you only buy E. purpurea (a.k.a. purple cone flower) preparations, and make sure they are organic (as always).
There are many other herbs that are used for acute viral infections, but I don't have space to talk about all of them here. If you want to know a whole bunch more about antiviral herbs, check out Stephen Buhner's book Herbal Antivirals. One other I will mention is goldenseal, Hydrastis canadensis. Goldenseal is a small woodland understory plant native to North America that contains berberine and hydrastine, the latter being very potently antiviral. However, this plant should not be used for colds or flus unless there is no other choice. Goldenseal is also on the UPS "At Risk" list due to over-harvesting and habitat destruction. Like echinacea, it is one of the few medicinal herbs that modern Americans have heard about and its reputation has unfortunately caused it to be misused and endangered. Therefore, I do not recommend goldenseal be used for colds and flus. It may be more appropriate for other clinical applications when used very judiciously, but I will not discuss that here.
Some additional options for diaphoresis to break a fever include hot teas of ginger root, yarrow leaf and flower, garden sage, thyme, oregano, rosemary, peppermint, horehound, hyssop, and many more. Drinking hot diaphoretic teas can help relieve symptoms related to fevers and help colds resolve more quickly. It is common to all traditional medical systems to wrap the feverish person in blankets, drink hot tea, sit by the fire, and sweat it out. Do so with caution with high fevers, as mentioned above.
Some herbs are great for taking daily during cold and flu season or over the long term to build a stronger immune system and prevent infections from taking hold in the first place. My favorite immune-boosting herb for long term daily use is astragalus root (Astragalus propinquus). It comes to us from Traditional Chinese Medicine where it is used as a tonic and a blood-builder. Studies have shown it to enhance innate immune and balance acquired immunity, specifically by enhancing the activity of white blood cells . It is also used as adjunctive therapy for cancer, as it increases white blood cell count and prevents neutropenia from chemotherapy, protecting cancer patients from chemo-related infections. It is mild tasting and very safe for all ages. Caution may be warranted for use during autoimmune flares. It can be taken in powder, tincture, decoction (a tea of the root simmer for at least two hours), bone broths, and soup stocks. It is excellent when combined with reishi mushroom and eleutherococcus (a.k.a. Siberian ginseng), all of which are immune stimulating and safe for long term tonic use. For more info on astragalus, read my materia medica monograph on it.
Eleuthero (Eleutherococcus sinensus) is another immune-stimulating root from Chinese Medicine and is used pretty similarly to astragalus, though is best for shorter term use (several months at a time for those with weak immune systems). It can be a little more stimulating to the immune system in the short term compared to astragalus.
In children, breastfeeding is very important for transferring immunity to many diseases from mother to child. Antibodies to many diseases, including bacteria and viruses, are transferred in the milk to the nursing infant. Breastfeeding can ensure that the child's immune system is as robust as possible as they grow older, and can help colonize them with healthy bacteria and important nutrients and fatty acids that you cannot get from factory-made formula. Nursing for at least one year is good, but nursing for 2-4 years is optimal, especially for CFers and immune-compromised children. For parents that cannot nurse their children, there are human milk banks available in most countries. These are organizations that provides human milk to infants that need it, given by nursing parents who have excess milk production. Human milk is way, WAY healthier than infant formula for many reasons that I can't go into here. And the good thing about getting milk from a milk bank is that this will increase exposure to multiple nursing people's antibodies and expand the diversity of antibodies the infant receives, therefore increasing the breadth of immunity. So... maybe everyone should do this?!
In addition, many studies have shown how taking probiotics, either in food or supplements, can help improve immunity and prevent respiratory infections infections in adults and children [18,19, 20]. For more information on how to choose a good probiotic, read this article.
Lastly, hygiene is very important to think about during cold and flu season. Washing hands frequently when in public places (especially hospitals and doctor's offices!) with soap and water or alcohol-based hand sanitizers is important. Avoid triclosan-based soaps and hand-sanitizers, not only because triclosan is carcinogenic and gets into the public water system, but also because bacteria are now becoming resistant to it. Soap and water still works, as does alcohol. Also, colonize yourself with good bacteria from natural places and healthy soils. These good bacteria educate your immune system and compete with pathogens to protect you. Always cough or sneeze into your elbows or inside your shirt, not into your hands, and wash your hands after blowing your nose or touching your face if you have a virus. Hands are the most common tools of cross-contamination. So be conscious of public door knobs and handles. When I'm in the hospital I always touch elevator buttons with my elbows, knees, or my fist-knuckles (not my finger tips). Little things like that can sometimes make a difference.
Eating nutritious, anti-inflammatory foods during a cold or flu is very important for hastening recovery and reducing symptoms. Garlic and onions, as mentioned above, are excellent choices, as well as spicy soups and broths. One of my favorite things to eat when I have a cold is spicy tom-kha soup (a Thai coconut soup). Drinking plenty of fluids is important, especially in the form of hot herbal teas, soups, and broths. Bone broth is a very nutritious and healing food for illness. Generally it is important to avoid inflammatory and hard to digest foods when we are sick, such as sugar, rancid oxidized oils, gluten, dairy, sodas, fried foods, and junk food. Simple, warm, well-cooked foods are best. Vitamin C in food form is helpful, such as from cabbage and sauerkraut, whole citrus, kiwi, blueberries, and other organic berries. Vitamin C in supplement form is not as helpful, and sometimes can be inflammatory (as with ascorbic acid).
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