Research Suggests Black Tea Inhibits COVID-19by Bashar Khiatah, MD & Amylee Amos MS, RDN, IFMCPNews
The world is facing an unprecedented crisis in the COVID-19 pandemic. Amongst the uncertainty, many are left questioning what we can do to fight this virus as we isolate in the comfort of our own homes. It goes without saying that we should all be following the CDC recommendation regarding physical isolation or social distancing, personal hygiene, and home sanitation. We can also follow the advice regarding nutrition from the many health institutes who recommend eating foods that reduce inflammation and naturally boost your immune system. But beyond these guidelines and words of advice, is there any research that supports specific interventions that we can implement at home to fight this virus? It turns out, there is, and as usual it is a solution that our ancestors have used for generations.
COVID-19, or SARS- CoV-2 (Severe Acute Respiratory Syndrome- Coronavirus) is a single-stranded RNA virus. Coronaviruses are known to have the largest genome among RNA viruses. This genome consists of one open reading frame that is responsible for virus replication (1,2). COVID-19 is known to actively replicate in the intestinal tract (3). All coronaviruses encode papline-like protease and chymotrypsin-like protease for proteolytic processing during virus maturation (4,5). This basically means that the virus needs these specific protein breaking enzymes in order to mature and function. As a result, the chymotrypsin-like protease has been considered a very important molecular target for a novel anti-SARS CoV drug (5,6).
A search of the Natural Product Libraries found that 720 pure natural products were investigated for compounds that could lead to a potential drug that has anti-COVID-19 efficacy. This was later narrowed down to 10 different compounds and mixtures that had strong potential for anti-COVID-19 efficacy. Most of these compounds come from black tea, green tea, oolong tea, and pu-erh tea. In other words, the compounds that have been found to have an anti-COVID 19 effect are the polyphenols that are found in teas. All tea comes from the same plant species, Camelia sinensis. Different teas are made from this plant based on their processing. For example, green tea has been well studied for its polyphenol benefits because the tea leaves are unoxidized, which is why they retain their green color. Meanwhile, black and pu-erh teas are processed with a high degree of fermentation, which produces new chemical compounds (7). A Chinese research group studied these compounds in tea, and investigated whether they can inhibit chymotrypsin-like protease activity or not (8). They found that black tea significantly inhibited chymotrypsin-like protease activity. Furthermore, they dove deeper to specifically determine the molecule that is responsible for such activity and they reported that Theaflavin-3,3′ -digallate (TF3) was responsible for this activity. Apparently, in the process of fermenting black tea, catechins naturally found in tea get converted into this active compound TF3. This study was carried out in-vitro and found that TF3 completely inhibited COVID virus replication in cell culture. Another study reported that theaflavins extracted from black tea were able to completely neutralize bovine coronavirus and rotavirus infections (9).
It’s important to note that this is preliminary data. However, incorporating three cups of black tea into your daily routine is an incredibly simple and cost effective intervention, and it may help you to fight this pandemic-causing virus. Unfortunately, it seems as though we are going to be dealing with this pandemic for the foreseeable future. It is without a doubt taking a toll not just on the physical health of the nation, but on the mental health of the nation. Substantial evidence from previous studies have shown the impact of previous SARS, MERS, influenza, and Ebola epidemics on the psychological health of at-risk populations. Recent polls show that there is more than a 25% increase in depression and anxiety, an increase that has pushed psychologists to warn of a post COVID pandemic of depression. In a recent poll 36% said COVID-19 is seriously affecting their mental health, and 59% of poll takers said it's having a serious impact on their daily life. But of course, knowledge is power, and you now have one more intervention to utilize to help you prevent or fight off this virus. So perhaps you can use your new tea time to sit back, relax, and try to find a moment of stillness in your mind, knowing that you are doing everything you possibly can to ward off or fight this virus and using all of the available research to do so!
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- Zhavoronkov, Alex; Aladinskiy, Vladimir; Zhebrak, Alexander; Zagribelnyy, Bogdan; Terentiev, Victor; Bezrukov, Dmitry S.; et al. (2020): Potential COVID-2019 3C-like Protease Inhibitors Designed Using Generative Deep Learning Approaches. ChemRxiv. Preprint. https://doi.org/10.26434/chemrxiv.11829102.v2
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- Chen CN, Lin CP, Huang KK, et al. Inhibition of SARS-CoV 3C-like Protease Activity by Theaflavin-3,3'-digallate (TF3). Evid Based Complement Alternat Med. 2005;2(2):209–215. doi:10.1093/ecam/neh081
- Clark KJ, Grant PG, Sarr AB, Belakere JR, Swaggerty CL, Phillips TD, et al. An in vitro study of theaflavins extracted from black tea to neutralize bovine rotavirus and bovine coronavirus infections. Vet Microbiol. 1998;63:147–57.