In June 2018 researchers from the USA and Singapore published the results of their study to assess whether coffee or tea was associated with the risk of hypertension in an Asian population. 63,257 Chinese individuals, aged between 45-74 years, were included in the study. Information on coffee and tea consumption plus other lifestyle factors were collected at the start of the study. After an average follow-up of 9.5 years, 13,658 cases of hypertension had been diagnosed. Results showed that individuals consuming less than 1 cup of coffee per week or approximately 3 cups per day had a reduced risk of hypertension when compared with those drinking one cup of coffee per day. However, those individuals who had the highest intake of coffee (over 300 mg/day) had a 16% increase in risk of hypertension. Daily drinkers of black or green tea also had a slight increase in the risk of hypertension when compared to those who drank tea less than once a week, but these risk estimates became non-significant after adjusting for caffeine intake.
Chei CL et al. Coffee, tea, caffeine, and risk of hypertension: The Singapore Chinese Health Study. Eur J Nutr. 2018 Jun;57(4):1333-1342.