Green tea is high in antioxidants and is often touted for its many health benefits – but the drink may not be beneficial for some medications.
According to BBC News, a new study from Japan found that green tea blocks the efficacy of nadolol, a high blood pressure drug.
Researchers found that nadolol’s ability to lower blood pressure was stunted after volunteers drank green tea. Follow up tests revealed that green tea blocked a drug transport found in the human gut, which helps to move nadolol into certain cells.
In the patient leaflet for nadolol tablets, consumers are warned that certain medications, including herbal remedies, can interact with the drug’s effectiveness. Green tea was not included on this list.
"What is clear as health care providers is that we need to ask patients about their consumption of various fruits and supplements such as grapefruit and green tea, and this needs to be documented in the clinical notes,” Sotiris Antoniou, a spokesman for the Royal Pharmaceutical Society and a consultant pharmacist in cardiovascular medicine, told BBC News.