Is black tea an immunity booster for COVID-19?

Every sector in the world from oil and gas, automobiles, air and travel, HORECA (hotel/restaurant/catering), insurance, shipping, printing, banking, apparel/fashion, luxury to FMCG (fast-moving consumer goods) products are hit hard by the present coronavirus pandemic. As analysts predict, the coronavirus disease (COVID-19) has delivered the swiftest and hardest global economic shock in modern history. 

The direct negative impact and the subsequent ripple effect on industrialised nations or on developing countries both will be extraordinarily significant. The COVID already infected over one million people while the death toll has reached 75,000 where a worldwide recession cannot be avoided. In this scenario, purchasing power and the consumer demand of all nations are bound to decline drastically.  

Is there any silver lining in this dark cloud for Ceylon Tea? The Tea Research Institute of Sri Lanka (TRI) has released a scientific paper under the theme: ‘Antiviral properties of tea – black tea may become the unique brew of choice with no side effects, to fight against coronavirus?’.

Many attempts are ongoing globally in search of therapeutic options, to recognise antiviral agents which could treat patients affected by COVID-19. However, ‘prevention is better than cure’. Therefore, in the context of healthy living, TRI has made a genuine effort to investigate the ‘Power of Ceylon Black Tea’ as a potential booster to aid one’s immune system to fight against the virus when confronted. 

TRI has quoted a recently conducted research study from Taiwan where the chemical structure of 64 compounds had been bioinformatically modelled against SARS-CoV-2. It had been revealed that theaflavins could potentially inhibit a critical SARS-CoV-2 virus, and thereby, theoretically inhibit COVID-19. Clinical trials, however, need to be initiated before claiming benefits against COVID-19 in humans. Theaflavins are antioxidant polyphenols that are formed during the enzymatic oxidation process (fermentation) in the manufacture of black tea. In contrast to green tea, black tea is rich in theaflavins due to the different manufacturing process. Due to the presence of catechins, flavonoids, polyphenols, amino acids, etc. in black tea, it is perceived to offer active antiviral activity. Green tea is said to have similar properties at different levels.  

As quoted by TRI, many epidemiological studies have shown that regular consumption of tea is linked to the lowering of cholesterol levels, high blood pressure, certain types of cancer and cardiovascular diseases. The major chemical constituent found in black tea is polyphenols, particularly the flavonoids that have been reported to possess antioxidant, anti-inflammatory, anti-atherosclerotic, anti-mutagenic, anti-tumour and anti-viral activities. It has been popularly accepted by the scientific world that daily consumption of three to four cups of black tea (without sugar or milk) by an individual is probably sufficient to trigger some of these activities in the human body.  

The TRI release has highlighted that several studies undertaken in different countries have demonstrated the potential benefits of black and green tea consumption in controlling influenza and common cold generally caused by viral infections. Tea catechins can bind onto the surface of the influenza virus and inhibit the spread. An alkaloid, found in tea is theaflavins, a chemical shown to alleviate respiratory diseases such as asthma, chronic bronchitis and other lung diseases. It relaxes and opens air passages in the lungs making it easier to breathe. Inhaling boiling water mixed with black tea can facilitate the clearing of the passages towards the lungs. As the COVID-19 epidemic is a similar illness where the patients find it difficult to breathe. Please note that black tea is neither a medically proven prophylaxis nor a treatment against COVID-19, but it is worth conducting further research to investigate the possible anti-viral benefits of theaflavins in black tea against COVID-19.

The scientists at the Sri Lanka Tea Board Laboratory suggest that frequent consumption of hot black tea is capable of flushing viruses trapped in the throat area. This practice is believed to improve immune capacity and inhibit inflammation due to catechins and polyphenols contained in black tea. Further, inhaling the fumes (steam) of hot black tea at high temperatures facilitates the removal of viruses trapped around the nasal area and opens a pathway for the tea theaflavins to reach the lungs and protect it from viruses.  

In the light of above explaining, it could be assumed in respect of the circumstantial evidence available that daily consumption of black tea (three to four cups without sugar or milk) is very useful and linked to the boosting of the immune system of normal human beings against respiratory diseases. COVID-19 is an influenza-like illness which could be perceived to be curtailed by theaflavins, one of the most active ingredients in black tea as explained in this review. 

Sri Lankans habitually consume three to four cups of Ceylon Black Tea and perhaps certain avid connoisseurs even more. Therefore, in addition to epidemic control measures, social distancing and hot local temperatures (between 26°C-32°C), the practice of drinking tea may also contribute to the low incidence of infected patients with coronavirus. Just for comparison purposes, take a brief look at the given table as of 7 April on the COVID-19 statistics.

The infected cases and the cases per million people in Sri Lanka are comparatively low. It could be due to a combination of multiple reasons, which certainly requires an in-depth investigation. It is premature to make concrete claims until in-vivo experiments or research and development on living cells are undertaken as per WHO guidelines. Nevertheless, Sri Lankans strongly believe that Ceylon Tea, the miracle black tea beverage is certainly one of them. 

(Courtesy of Sri Lanka Tea Board)