High tea intake helps prolong life

Drinking two or more cups of tea per day appears to lower the risk of mortality, regardless of genetic variation in caffeine metabolism, results of a prospective cohort study have shown.

By accessing the UK Biobank, the authors identified 498,043 men and women aged 40‒69 years who completed the baseline touchscreen questionnaire from 2006 to 2010. They then assessed the self-reported tea intake and mortality from all causes and leading causes of death, including cancer, all cardiovascular disease (CVD), ischaemic heart disease, stroke, and respiratory disease.

Over a median follow-up of 11.2 years, higher tea intake showed a modest association with lower all-cause mortality risk among participants who drank at least two cups a day.

Compared with no tea drinking, the hazard ratios were 0.95 (95 percent confidence interval [CI], 0.91‒1.00) for participants drinking 1 or fewer cup per day, 0.87 (95 percent CI, 0.84‒0.91) for 2‒3 cups, 0.88 (95 percent CI, 0.84‒0.91) for 4‒5 cups, 0.88 (95 percent CI, 0.84‒0.92) for 6‒7 cups, 0.91 (95 percent CI, 0.86‒0.97) for 8‒9 cups, and 0.89 (95 percent CI, 0.84‒0.95) for 10 or more cups.

Inverse associations were also observed for mortality from all CVD, ischaemic heart disease, and stroke. These findings were consistent regardless of whether participants also drank coffee or not, or of genetic score for caffeine metabolism.

Notably, the authors did not explore the potentially significant aspects of tea intake, such as portion size and tea strength.

“These findings suggest that tea, even at higher levels of intake, can be part of a healthy diet,” the authors said.