Effect of Tea Catechins on Influenza Infection and the Common Cold with a Focus on Epidemiological/Clinical Studies

Abstract

Influenza and the common cold are acute infectious diseases of the respiratory tract. Influenza is a severe disease that is highly infectious and can progress to life-threating diseases such as pneumonia or encephalitis when aggravated. Due to the fact that influenza infections and common colds spread easily via droplets and contact, public prevention measures, such as hand washing and facial masks, are recommended for influenza prophylaxis. Experimental studies have reported that tea catechins inhibited influenza viral adsorption and suppressed replication and neuraminidase activity. They were also effective against some cold viruses. In addition, tea catechins enhance immunity against viral infection. Although the antiviral activity of tea catechins has been demonstrated, the clinical evidence to support their utility remains inconclusive. Since the late 1990s, several epidemiological studies have suggested that the regular consumption of green tea decreases influenza infection rates and some cold symptoms, and that gargling with tea catechin may protect against the development of influenza infection. This review briefly summarizes the effect of tea catechins on influenza infection and the common cold with a focus on epidemiological/clinical studies, and clarifies the need for further studies to confirm their clinical efficacy.

The upshot of Polyphenolic compounds on immunity amid COVID-19 pandemic and other emerging communicable diseases: An appraisal

“…Regular consumption of green tea has been shown to decrease influenza infection and some cold symptom rates. In addition, gargling with tea catechins protects against influenza infection and common cold [49]. A study has also shown that consuming green tea supplements twice daily for 3 months resulted in a significant decrease in cold or influenza symptoms by approximately 23%.…”

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“…Last three decades several studies suggested that the regular consumption of green tea decreases influenza infection and some cold symptoms. The gargling with tea extracts and/or flavonoids may protect from influenza virus [18]. EGCG-fatty acid derivative is important because fatty acid on the phenolic hydroxyl group increase viral and cellular membrane permeability which protects from viral infection [19].…”

Covid-19: Überlegungen zu Voraussetzungen von phytotherapeutischen Empfehlungen

“…Mehrere epidemiologische Studien haben gezeigt, dass der regelmäßige Verzehr von grünem Tee die Influenza-Infektionsrate senkt [4]. In klinischen Studien wurden meist standardisierte Katechinextrakte verwendet.…”