Green tea extract merits more study as a potential remedy for pulmonary fibrosis, the scarring of lung tissue that can make it more difficult to breathe.
A 2020 study in the New England Journal of Medicine examined the effects of green tea extract, epigallocatechin gallate, in treating twenty patients with pulmonary fibrosis. The study found that the tissue levels of treated patients were closer to normal than those of untreated patients. The extract has previously been studied as a successful method for inhibiting the effects of protein mutations associated with pulmonary fibrosis and lung cancer.
A longer-term, randomized clinical trial would help reach a more definitive conclusion.