Wherever you are in the world, nature is abounding with vast, untapped sources of health-sustaining plant chemicals… not far from your doorstep.
A while back I wrote about wild herbs for dry cough - nature’s ‘demulcent’ or soothing remedies for the irritated, inflamed membranes of influenza. But there's so much more to talk about! So many plants, so little time.
In this article we'll cover three abundant wild remedies for respiratory support. These herbs, when taken alone or in conjunction with other immune stimulants, immune modulators and antivirals like echinacea, elderberry, vitamin D and astragalus, may help boost your defences and improve disease outcomes during this critical time.
Please note that the information given here is not intended as a substitute for conventional medical guidance on the treatment of COVID-19. The up-to-date official medical guidelines can be found online in the Internet Book of Critical Care. However, herbs are being trialled in China as first-line treatments for the virus and, while few herbalists outside of China have much experience treating the infection, it seems that it may be treated similarly to influenza and other respiratory infections.
Rock Rose (Cistus spp.)
We'll start with my favourite: the dashing Rock Rose. This undervalued Southern European herb is a powerhouse of medicinal activity. The plant itself is beautiful, with either pale pink, fuschia or creamy white flowers and a heady, sweet aroma.
Gum cistus or Cistus ladanifer boasts long sticky leaves dripping with resinous sap known as ‘labdanum’ which is incredibly healing to the skin. As with other herbs that are externally healing, like calendula, Cistus species. can be used just as successfully for healing internal irritations and inflammations of the mucous membranes, such as those of the digestive and respiratory tracts.
Cistus species are therefore incredibly useful for healing gastritis, ‘leaky gut’ or intestinal permeability, and chronic bacterial, fungal or viral infections. Most research has been done on Cistus incanus, a hybrid of C. albidus and C. crispus (both found in the Algarve) with very promising effects - it has shown activity against HIV, Ebola, Lyme/Borrelia, Candida and Aspergillus (common mould) infections. It has also been shown to inhibit the growth of bacteria and bacterial biofilms - the presence of which is a major contributor to chronic disease.
Most importantly for us however, it has also shown antiviral activity against influenza A and rhinoviruses specifically, so it could be especially indicated for COVID-19 infection. It improves viral outcomes by targeting the envelope proteins on viral capsules, preventing them from attaching to host cells and replicating. A Cistus extract reduced common cold symptoms in one trial of 300 people, and decreased both symptoms and inflammatory biomarkers in another trial of 160 patients with upper respiratory tract infections.
Fellow herbalist Nikki Darrell in Ireland also recommends using Cistus species for sinusitis, presumably for their drying, warming and powerful antimicrobial effects. Nikki has used Cistus for bacterial, fungal, viral, acute, chronic or allergic sinus issues with good results.
The best way to use Cistus - any species is fine though I prefer C. ladanifer because of its incredible smell - is to make a tea from the fresh or dried leaves and take 2-3 cups daily, increasing that during an infection. You can also tincture it fresh to preserve the vitality of the plant.
Nasturtium (Tropaeolum majus)
Nasturtium is another gorgeous flower that can be added to summer salads along with edible flowers like calendula, borage and mallow - both for its beauty and its delicious pungent taste.
It’s that spicy kick which gives you a clue to Nasturtium’s properties - similar to watercress and rocket, the peppery compounds are called isothiocyanates and are powerful antibiotic substances. A tea made from the leaves can be used as an external wash for wounds or genito-urinary infections, and consumption of the leaves will help keep bacterial infections of the digestive and respiratory systems at bay.
However, the importance of nasturtium in flu prevention comes more from its rich micronutrient content, in my opinion. The leaves and flowers contain large amounts of vitamin C, as well as zinc and iron. These nutrients, along with selenium (brazil nuts, fish and eggs) and vitamin A (liver, cod liver oil or in vegetables as beta-carotene) are crucial for the maintenance of a healthy immune system.
Taken as a tea or extract, nasturtium is a stimulating expectorant for the lungs - it is heating, and helps draw out stuck phlegm by irritating the membranes of the respiratory tract. This isn’t necessarily indicated during COVID-19 infection, as I explained in my last article. However, as you’ll hopefully agree, fresh nasturtium leaves have a distinct demulcent quality to them, and feel quite soothing on the membranes. So, my advice is to stick to the fresh leaves and flowers in salads, soups and sandwiches - that way you’ll also be getting the micronutrients in their whole bioavailable form.
Nasturtium leaves and flowers contain large amounts of vitamin C, as well as zinc and iron.
Olive leaf (Olea europaea)
Just like Cistus species, olive leaf has been shown to have broad-spectrum antimicrobial properties with activity against bacteria, fungi, parasites and viruses, including the influenza virus. It's also a very powerful anti-inflammatory, which reduces the inflammatory cytokines produced by the body during viral infections and makes us feel better sooner.
Oleuropein, one constituent of olive leaf, is thought to be a very effective antiviral compound when taken up into human cells. An enzyme inside the cell converts oleuropein into other compounds which attack viruses from inside the host cell, where they live. And this is just one compound in olive leaf. As a whole herb, olive leaf is also traditionally used to gently lower a fever - another great reason to add this herb to your influenza first aid kit. For more information on how to effectively manage a fever, read my last article.
Olive leaf has also been effective in clinical studies - an extract containing 20g olive leaf, when given to 32 high school athletes for nine weeks during their competitive season, produced a 28% reduction in sick days compared to the control group. The authors point out that, while the extract did not reduce upper respiratory infections per se, the fact that it shortened the duration of infections was significant considering that the athletes were consuming a ‘sub-optimal’ diet.
However, in my opinion, the potential benefits of olive leaf in preventing and treating COVID-19 go beyond its antiviral effects. Every day we hear that the overwhelming number of people lost to this virus have either one, two or three co-morbidities (pre-existing illnesses) - namely high blood pressure, cardiovascular disease and diabetes. Olive leaf has been shown in clinical studies to lower systolic and diastolic blood pressure, improve blood sugar control and reduce the oxidation of cholesterol molecules - all factors which contribute to a healthy metabolic and cardiovascular system. Polyphenols found in olive leaf and olive oil may also help reduce body weight and prevent weight gain - another crucial factor in COVID-19 prevention.
Fresh olive leaves make a very mild, pleasant-tasting tea that can be consumed alone or with Cistus leaves for an all-round anti-infectious, immune-boosting drink.
The one thing linking all the herbs mentioned in this article is that you can harvest them to your heart’s content. Both Cistus species and olive trees are abundant in the wild, and nasturtium is a common spring and summer weed available all over the world, from Europe to the Andes to Asia. If Cistus and olive leaf are not available near you, try to find good quality dried herb sources, or get Mediterranean friends to post you some!
If you'd like to purchase some of these herbs in tincture form, I have some brewing and am planning to formulate them into an affordable immune-boosting tonic soon. Get in touch if you'd like to know when it's ready :-)