The study, conducted and published by the Annals of Internal Medicine, included 498,043 participants who were aged between 40 to 69 and part of the UK biobank, a database resource that contains health information about nearly half a million people in the UK.
Participants completed a baseline questionnaire between 2006 to 2010 and were examined for a median of 11.2 years. Researchers also looked at information about the individuals’ tea intake, as they self-reported how much they drank.
Results of the study found that out of the participants who said that they drank tea on a regular basis, 89 per cent of them consumed black tea. When compared to people who said that they didn’t drink any tea at all, participants who drank black tea had between a 9 to 13 per cent lower mortality risk.
Higher tea consumption, which is two cups a day or more, was also linked to a lower risk of death due to cardiovascular disease, ischemic heart disease, and stroke.
The study also noted that higher tea consumption was associated with a lower mortality risk regardless of what temperature the tea was, how much milk or sugar was in it, and genetic variations that affect one’s ability to take in caffeine.
While findings suggest that tea can be part of a healthy diet, there were some limitations to the study as the portion size of each cup of tea and the caffeine strength in it was not evaluated.
During an interview with Time, one of the study’s researchers, Maki Inoue-Choi, an epidemiologist at the National Cancer Institute, said: “The association between tea consumption and cardiovascular mortality may be driving the association between tea consumption and all-cause mortality.”
Inoue-Choi also acknowledged that even though the findings may encourage people to have more tea, they “shouldn’t change how many cups of tea to drink every day because of these results”.