Viruses are Supervillains, Herbs are Superheroes
The plural of anecdote is starting to look like anecdata
In July of 2022, I began publicizing a growing body of scientific literature suggesting mint-family herbs can help fight viral infections. In the ensuing year and a half, every person I convinced to adopt a daily mint habit has remained never-Covid. Nearly everybody I know who doesn’t have a routine mint habit has had Covid at least once. The bet that mint has virus-fighting superpowers is starting to look like easy money.
Prevention
Loved ones who haven’t adopted routine mint-family herb habits typically offer the lame excuse, “I don’t really enjoy mint tea.” In my mind, this lands about the same way as “I don’t really enjoy seatbelts.” It sends me back to the early days of the AIDS crisis, when fools whined about not enjoying condoms. We’re talking about cheap and easy safety insurance here! Enjoyment comes in the form of not having to burn up quite so much mental energy navigating (or convincing yourself to ignore) scary risks.
As I mentioned in my initial mint-versus-Covid post, there are dozens of other things a tea-hater could easily try. For one thing, a little honey, sugar, or artificial sweetener can work wonders for palatability. Also, some mint family herbs - such as self-heal flowerspikes - are pretty much flavorless. Somebody could sneak them into your morning coffee and you’d have no idea.
My general theory is that mint-family herbs that taste delicious and have been commonly eaten for thousands of years in places where people tend to enjoy long lives are a good bet for daily use. Over the Thanksgiving holiday, most of my nearby family had Covid — so I brought them stuffing that contained literally 20x more sage, rosemary, thyme, and oregano (mint-family herbs) than the traditional recipe calls for. Even if it didn’t help my loved ones feel better faster, it was still hands-down the best stuffing I’ve ever made. Likewise, a handful of fresh mint or basil can transform boring everyday salads into something kinda special.
Treatment
The idea that drinking six teabags worth of mint tea every day can prevent viral infections seems like a good bet, but I’ve also been gaming out what I’ll do if the bet goes south and I end up getting infected. A bedrock virological principle is that the earlier you start treating an infection the better the treatment works. It’s important to shut the stable door before the horse has bolted. Unfortunately, most herbal products take a long time to ship - so advance planning is key.
As an application of this thinking, I convinced my primary care physician to give me just-in-case prescriptions for a ten day course of Paxlovid and metformin to bring along with me on an overseas trip I took last summer. Which reminds me to tell you that my novid husband and I don’t live like hermits. Our daily mint habits really might be the only thing setting us apart from everybody around us catching Covid for the second or third time.
Combination therapy
Another basic virological principle is that combinations of antiviral medicines often work much better than monotherapy. With that thought in mind, I’ve been entertaining the idea that mixtures of herbs with complementary antiviral properties could work better than mint alone.
Tea made from honeysuckle buds (Lonicera japonica) unfortunately doesn’t taste much like the fresh blossoms I remember eating as a kid, but it’s sort of an OK tea. Honeysuckle buds are one component of a Seven-Flavor Herb Tea product that a recent clinical trial suggests might prevent Covid infection. Seven-Flavor Herb Tea also includes the mint-family herbs bohe, perilla, and patchouli.
A challenging aspect of scientific studies examining traditional Chinese medicines is that they typically involve complex mixtures of botanicals - so it’s hard to tell which individual components might be doing the heavy lifting. On the other hand, it’s conceivable Seven-Flavor Herb Tea might already be doing the exact thing I’m hoping for (combination treatment akin to modern antiretroviral therapies). I’ve got honeysuckle buds in my pantry and I’m planning to throw some into the mix if I catch a viral infection.
Wormwood (genus Artemisia) has moderate amounts of caffeic acid (the main antiviral in mint). Cell culture testing suggests wormwood also has additional antivirals, including the Nobel prizewinning antiparasitic drug artemisinin. A fascinating hypothesis I first ran across in an epic ACX post is that the Nobel prizewinning antiparasitic drug ivermectin might sometimes be effective for treating Covid because it inadvertently cures people of parasites. Parasitic infections are known to be immunosuppressive, so the idea is that getting rid of parasites could plausibly have the side-effect of helping people mount a better defense against viral infections.
It’s estimated that perhaps as many as a quarter of Americans have some form of chronic parasitic infection. It’s especially (but not exclusively) a problem in poorer parts of the country. Wormwood tea has been used to treat parasitic infections since antiquity (hence the plant’s common name). Sweet wormwood (Artemisia annua) makes a pleasant tea. It also comes in a pellet form that adds a tasty crunch to salads. It’s a handsome plant that’s easy to grow from seed. I’m definitely going to throw some sweet wormwood into the mix if I get infected.
Despite its common name, fishmint (Houttuynia cordata) is more closely related to black pepper than to mint. Although it has almost no caffeic acid, fishmint showed high antiviral potency in the early-pandemic PNAS paper that first sent me down this rabbit hole. It seems like another good candidate for having antiviral effects complementary to those of mint.
Antihistamine effects
It’s common knowledge that quality sleep is important for many aspects of health, including fighting viral infections. A meta-analysis of 18 studies indicates that the familiar sleep aid melatonin can blunt the severity of acute Covid.
In addition to promoting sleepiness, melatonin also appears to play a role in shifting immune responses away from damaging histamine-mediated inflammation and toward a more effectively antiviral “TH1” response. Melatonin may also have direct antiviral effects. Le-Trilling and colleagues have shown that the primary antiviral compound in mint family herbs, caffeic acid, stimulates innate immunity by up-regulating a cellular defense enzyme called heme oxygenase-1 (HMOX1). Melatonin, like caffeic acid, up-regulates HMOX1.
Plants can produce melatonin, and peppermint, thyme, and sage reportedly contain exceptionally high levels. Although the ~0.2 mg dose of melatonin you might expect to get from a cup of tea brewed from 5 grams of dried mint-family herbs is lower than the 2-20 mg melatonin doses tested in clinical trials, the amount of melatonin in tea is within range of doses that can help people sleep.
Another familiar antihistamine, famotidine (Pepcid), has shown encouraging results in clinical trials against Covid. Famotidine isn’t thought to act directly as an antiviral - instead, it exerts TH1-skewing antihistamine effects similar to melatonin. Azelastine (Astepro) is another familiar over-the-counter antihistamine with documented anti-Covid effects.
Meta-analyses of clinical trials for another TH1-skewing antihistamine, curcumin, indicate that it can safely help prevent and treat Covid. Turmeric, which gets its vibrant color from curcumin, is a wonderful ingredient in all sorts of savory dishes. Fresh turmeric root adds a complementary spicy-floral dimension to any dish that calls for fresh ginger.
After posting an initial version of this article, my brother and I had a useful debate about the wisdom of taking anti-inflammatory medicines that might theoretically only treat symptoms while failing to tackle the underlying viral infection. It’s an important point. There’s an overwhelming body of evidence suggesting that the familiar anti-inflammatory drug acetaminophen (Tylenol) makes Covid worse. While it would obviously be a terrible idea to randomly pop whatever anti-inflammatory drugs happen to be in the medicine cabinet, the literature clearly shows that melatonin and famotidine alleviate symptoms while also accelerating the clearance of the underlying viral infection. Furthermore, large numbers of people have been on long-term daily treatments with these drugs and serious disease side effects (such as worsening viral infections) haven’t been observed.
My current plan, in the event that I catch a viral infection, is to take a standard 20 mg dose of famotidine before lunch and a standard 5 mg dose of melatonin before bed1 . Plus I’ll whip up some nice turmeric black pepper curry - or maybe pop a gram of curcumin-piperine if I don’t feel well enough to cook. I’ll enjoy washing it all down with a pitcher of mixed-herb tea.
Long Covid
Emerging evidence suggests long Covid might be caused by persistent infection that quietly lingers for many weeks or months after resolution of the initial acute infection. It makes me wonder whether mint tea could be a cheap and easy thing for people suffering from long Covid to try. It’s a convenient experiment because long Covid sufferers can easily monitor whether a given herb, drug, or combination of herbs and drugs alleviates their symptoms.
Appendix
The list below covers some other easy-to-obtain stuff that mint-averse loved ones could consider. The list isn’t comprehensive - just some things that have caught my attention over the years. The fantastic website C19early.org provides detailed meta-analyses of these and other proposed Covid-fighting agents.
There’s decent evidence that quercetin has direct antiviral effects that can help mitigate Covid symptoms. Citrus, apples, onions, parsley, and sage have a fair amount of quercetin. An important concern is that quercetin supercharges liver enzymes that could accelerate the clearance of a wide variety of drugs, including Paxlovid, from the bloodstream. I’m not planning to take quercetin, but it’s something people with long Covid could consider.
Vitamin D deficiency is unhealthy in all sorts of ways, likely including poor Covid recovery. You might want to do some back-deck mint gardening and get a little sun. Zinc might help too. I take a daily multivitamin as a hedge against vitamin and mineral deficiency.
Nigella seeds are loaded with caffeic acid. A meta-analysis of 14 clinical studies indicates Covid patients given nigella seeds had less severe Covid symptoms and recovered faster. Nigella seeds are tasty, have great texture, and are generally suitable for any culinary application where you might use sesame seeds. They’re especially good on salad.
Black chokeberries — also known as aronia — have tons of caffeic acid and have been shown to inhibit SARS-CoV-2 in culture. I find chokeberries a little too astringent to eat by the handful, but they make a nice addition to yogurt or oatmeal.
Sunflower seeds have moderate amounts of caffeic acid and melatonin. They’re great in mint-family pesto.
Za’atar is nice sprinkled on toast, salad, or yogurt.
Cocktails made with mint-family herbs are tremendously entertaining. I’m currently enthralled with the recipes posted at Artemisia Farm & Vineyard. Unfortunately, alcohol can disrupt sleep. Furthermore, alcohol can have serious interactions with metformin and melatonin. Cocktails are an occasional day-to-day indulgence that I’ll temporarily suspend if I catch an infection.
The clinical data for cannibidiol (CBD) aren’t particularly encouraging, and when I tried a pilot dose of the stuff I had a fitful night’s sleep interrupted by strange dreams. Having a viral infection is nightmare enough - the last thing I need is CBD putting a foot on the gas.
The roots of a mint-family herb called Baikal skullcap (Scutellaria baicalensis) contain a proposed antiviral called baicalein. Skullcap root tea is delicately spicy and earthy-tasting.
Although grand wormwood (Artemisia absinthum) likely has anti-parasitic and antiviral properties similar to sweet wormwood, grand wormwood is mindbendingly bitter and it contains a fair amount of thujone, which is poisonous in high doses. After trying a couple small samples of a bag of grand wormwood, I threw the rest in the compost. Though I do still enjoy good absinthe from time to time.
I’m not particularly impressed by clinical evidence for the Covid-fighting effects of an herbal extract called berberine, but it’s conceivable it could work in ways similar to metformin (which has been shown to reduce the risk of long Covid by 40%). A friend who couldn’t convince his doctor to let him have metformin resorted to using berberine instead. The friend has long Covid now. Way to go, friend’s doctor.
Disclaimers
•This article follows the time-honored tradition of scientists trying out ideas on themselves first. You should apply the scientific method and do your own background research before trying any of this stuff on yourself. Background research can include consulting a licensed medical professional (which I am not).
•The article is mirrored on my Medium account. Parts of the text - particularly the antihistamine section - have been revised in response to reader critiques (which I welcome!).
•I don’t have any financial stake in any of this stuff.
WebMD offers a useful tool for identifying potential interactions between drugs. I’m not currently taking any medicines, but a check of the drugs I’m considering finds only one minor interaction: famotidine might slightly increase concentrations of metformin by inhibiting its excretion via the kidneys.