A prospective study of half a million tea drinkers in the United Kingdom has shown that higher tea intake was associated with a modestly lowered risk of death. The study, led by researchers at the National Cancer Institute, part of the National Institutes of Health, is a large and comprehensive analysis of the potential mortality benefits of drinking black tea, which is the most common type of tea consumed in the U.K.
Past studies finding a modest association between higher tea intake and lower risk of death have mainly focused on Asian populations, who commonly drink green tea. Studies on black tea have yielded mixed results.
In the new study, the researchers found that people who consumed two or more cups of tea per day had a 9% to 13% lower risk of death from any cause than people who did not drink tea. Higher tea consumption was also associated with a lower risk of death from cardiovascular disease, ischemic heart disease, and stroke. The association was seen regardless of preferred tea temperature, the addition of milk or sugar, and genetic variations affecting the rate at which people metabolize caffeine.
The findings, which appear Aug. 30, 2022, in the Annals of Internal Medicine, suggest that black tea, even at higher levels of intake, can be part of a healthy diet, the researchers wrote.
The study involved 498,043 men and women between ages 40 and 69 who participated in a large cohort study called UK Biobank. The participants were followed for about 11 years, and death information came from a linked database from the UK National Health Service.
Inoue-Choi, M., et al. (2022) Tea Consumption and All-Cause and Cause-Specific Mortality in the UK Biobank: A Prospective Cohort Study. Annals of Internal Medicine. doi.org/10.7326/M22-0041.