Amid This Pandemic, a Look at Tea and Its Effect on Viruses

I find it interesting that, when investigating viruses, researchers often turn to tea—possibly to drink, but generally as something to analyze.

It’s way too early to know if this will hold true for COVID-19, but here are a few examples of how tea and its abundant polyphenols have been studied and may someday be part of our anti-virus toolkit.

pu-erh leaves
Yunnan Pu-Erh

SARS coronavirus

Severe Acute Respiratory Syndrome or SARS coronavirus (SARS-CoV) was first identified in 2003 when it swept through 26 countries in 2002–2003. A couple years later, a team of researchers based in Taiwan screened 720 compounds that were in a natural product library* to see if any of them combated the SARS coronavirus.

Of those hundreds of compounds, only 2 of them inhibited the virus: tannic acid and 3-isotheaflavin-3-gallate. Both of these compounds are polyphenols that are present in tea.

The researchers then looked at different teas and found that pu-erh and black tea extracts inhibited the virus more than did green or oolong extracts. They also looked at additional compounds in tea and discovered that the phenol theaflavin digallate, found in black tea, inhibited the virus (Chen et al. 2005).

pu-erh brew

Zika virus

The Zika virus, or ZIKV, was first identified in 1947, but then resurged in South America in the past few years, tragically affecting pregnant women who then gave birth to children with microcephaly, as well as causing Guillain-Barré syndrome and other neurologic problems. Currently, there is no vaccine for this virus, although there have been some promising recent studies.

A 2016 study evaluated the efficacy of the polyphenol epigallocatechin gallate (EGCG), found in green tea and therefore labeled a “natural drug,” against Zika virus.

bancha leaves
Japan Bancha

This particular phenol is effective against many viruses because it seems to interact with a host cell’s “lipid envelope, leading to a subsequent destruction of the virus particle” (Carneiro 2016). There’s even some preliminary indication that EGCG crosses the placental barrier and lessens (but not totally eliminates) ZIKV’s effects on an embryo, plus it’s safe for both embryo and mother (Carneiro 2016).

Still, this isn’t a perfect solution. Because EGCG isn’t stable and doesn’t easily permeate membranes, among other issues, it would need tweaking so that it’s available within the human body at a dose high enough to work. Natural compounds extracted from plants often have these problems, plus can degrade when exposed to oxygen (Bayraktar et al. 2017).

To make EGCG sufficiently available, it can be chemically altered it—or it can be encapsulated, the preferred method because it gets the phenol to where it needs to be, in the concentration that’s effective (Bayraktar et al. 2017). Research continues.

bancha brew

Influenza virus

A 2015 review of polyphenols found that they show a great deal of promise for preventing and treating flu. Our current treatments for flu are not always adequate, and tens of thousands of people die each year (61,200 during the 2018–19 flu season according to the CDC).

Polyphenols, naturally found in food, and particularly rich in tea, can damp down the replication cycle of viruses, can affect how viruses get into the host cells, and so on, which make them potentially valuable complements to current drugs.

eliya brew
Ceylon Orange Pekoe Nuwara Eliya

Roodabeh Bahramsoltani and team (2015) recommend that more study be done on nontoxic polyphenols that are known to be effective so that we may better understand how they work against the flu virus. With that knowledge, it’s possible that they “could be used as a skeleton for designing a novel generation of antiviral drugs” (Bahramsoltani et al. 2015).

Drink tea?

Well, laboratory tests using extracts from tea are definitely not the same as drinking a cup of tea.

Still, we all know that a plant-based diet is healthy for us. And more and more studies are demonstrating that tea provides measurable benefits, with some going so far as to argue that drinking tea is better than drinking water—although both hydrate, tea contains all those polyphenols that water does not.

I cannot say whether tea has any effect whatsoever against COVID-19, but in light of its overall benefits—including, and perhaps most importantly, simply the enjoyment that I get from drinking tea—I’m filling my cup yet again today.

Besides, things always look better when you’re holding a cup of your favorite tea!

bancha & teapot

*A note on libraries

There are many such product libraries, with 22 natural product libraries currently listed on the NIH website. “Natural products,” in addition to your expected plant and animal sources, include bacteria and fungi, extracts from natural products, and even synthetic compounds extracted from natural sources.

The advantage of using compounds obtained from such a library?

A large number of compounds are readily available.

And a natural product library specifically?

As we need to develop more drugs to address current needs, some scientists are shifting back to natural products, which fell out of favor with the advent of the pharmaceutical industry.

Some of the advantages of natural compounds?

For one thing, living entities have spent their existence as a species developing protections against infections and infestations—and against being eaten out of existence.

Phytochemicals [biologically active compounds found in plants] also demonstrate far greater structural diversity and complexity than the relatively simple molecules that populate most synthetic compound libraries, and their structural features tend to be more drug-like than randomly synthesised compounds. (Caithness Biotechnologies)

Further, on a practical level, there are fewer compounds in a natural product library vs a synthetic product library, which facilitates efficacy by smaller and/or less well-funded research groups.

eliya leaves
Ceylon Orange Pekoe Nuwara Eliya

All teas shown here are available at TeaHaus.
See previous post: Amid the COVID-19 Pandemic, a Look at Tea and Stress

–Bahramsoltani, Roodabeh et al., “The preventive and therapeutic potential of natural polyphenols on influenza,”
Expert Review of Anti-infective Therapy 14(1). 2016.
–Bayraktar, Oguz, et al., “Nanocarriers for plant-derived natural compounds,”
Nanostructures for Antimicrobial Therapy,  ed. by A. Ficai and A. Grumezescu, Elsevier, 2017.
–Carneiro, Bruno M., et al., “The green tea molecule EGCG inhibits Zika virus entry,” Virology 496:215–18. September 2016.
Caithness Biotechnologies, accessed March 18, 2020.
–Chen, Chia-Nan, et al., “Inhibition of SARS-CoV 3C-like protease activity by theaflavin-3,3′-digallate (TF3),”
Evidence-Based Complementary and Alternative Medicine, vol. 2. 2005.

16 thoughts on “Amid This Pandemic, a Look at Tea and Its Effect on Viruses

  1. Hi! I drink PG Tips every day. It’s affordable and delicious. 🙂 What tea are you drinking during this time? Anything special you believe in or would recommend?


    1. I too have PG Tips in my tea cupboard! When I’m not feeling well, I particularly like a strong and bold black tea. Mostly, though, I drink loose green tea, especially sencha from Japan and Lung Ching from China, just because I really like green tea and these are nice everyday teas. I also love oolongs, with their layers of flavor. I did have several single-origin black teas that I loved but none of them are available anymore, sadly. Okay, as I write this, I’m realizing that I’ll happily drink pretty much any tea, whatever the situation. I find any tea relaxing and comforting, which is something I think we all need right now. Thanks for writing!


  2. Very informative and very comforting since I’m a tea drinker myself and sweat by it. Can’t do without my cuppa before I start my day. I have also written a blog on tea called “The elixir of life” though nowhere close to scientific basis. More my addiction. Thanks for sharing, much appreciated!

    Liked by 2 people

    1. Thank you! I just checked out your blog—really interesting. We are just starting a 3-week “shelter in place” here and it’s frustrating to see people ignore the recommendation, as you illustrate in your recent blog.


    2. Me too. And I’ve nearly gone crazy for nearly two weeks because I can’t get fresh goat’s milk. Yes, I have milk in my tea but can’t tolerate cow’s milk and soy milk is revolting except in coffee. When I have black tea I put in stalks of lemon grass cut fresh from my garden, or basil and sometimes tumeric I understand is a natural antiseptic (or is it antibacterial? – I’d fallen down a drain in the dark and when hauled out, cleaned up, I was fed hot milk with much tumeric and honey.)

      Liked by 1 person

      1. Tea (black/green) itself is antibacterial, antioxidant, and more, but there’s little scientific evidence that drinking turmeric does anything. Honey used topically also has antibacterial properties. I’m glad there are a lot of research studies underway to closely look at the traditional uses of plants; some are very promising!

        Lemon grass is a very nice addition to tea I think! Have you tried adding both basic and lemon grass to tea? Seems like that would also be good.


        1. Dear Jill, Yes, often I put lemon grass (from my garden) in my black tea. Also variously, heaps of mint, or a sprig of rosemary or, basil. Also often I put a slit-open bird’s-eye chili in the pot. The mint though often I have simply without the tea.

          Liked by 1 person

          1. I too love just mint, or mint with lemon balm. And doesn’t the chili give a nice heat at the back of your mouth? So nice on a cold day—although the bird’s-eye are probably too hot for me! Do you grow your own chilis and herbs? Our yard is too shady to grow much beyond some mint and lemon balm.


          2. Yes, I grow my chilis. The bird’s eye crossed with a sweet chili my mother gave me so I have to be wary of those long ones. Usually I can nibble the bottom half-inch but then it bites so I use it in cooking. It’s too hot and dry here for lemon balm. I used to use it a lot.


          3. It sounds like you have a really nice garden! Nothing is better than veggies and herbs from one’s own garden, and fruit too. Decades ago we planted a peach tree in our yard but due to the total lack of sufficient sunlight, we have never seen a peach. Ah but the lemon balm—in our yard it tenaciously aims for total garden dominance. Too bad I can’t send it your way lol! I use it for tea, but what all did you use it for when you had it? It seems a natural with fish but I’m allergic to fish so I never cook that.

            Liked by 1 person

          4. Lemon balm with mint and lemongrass straight from my old garden for refreshing tea. My lemongrass struggled to get to 10″ height but move to hotter place sees it at ten FEET! But oh my goodness summer gets hot. Tomatoes boil in their skin! However cherry tomatoes do well. So it’s herbs, beans, citrus, pawpaws and quince. Too bad you can’t eat fish. I just about live on salmon and barramundi.


          5. Yeah my kids love salmon, and here in Michigan our freshwater pan fish is supposedly amazing. Ten-foot-high lemongrass must be pretty spectacular! You could probably singlehandedly supply a ton of tea shops. It sounds you live somewhere I’d love—hot! I’m always cold here. For awhile I worked in an office that routinely was 80°F and it was heaven.

            Although pawpaws are native to our region too, I never had one until a couple of years ago. It’s really a delicious fruit. But I do have some dried lemongrass so I’m going to try your suggestion; it sounds terrific. Thanks!


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