Drinkers of black tea might live longer, according to a study of a half million U.K. adults. Photo Adobe iStock.
Observational health data from a half million adults in the United Kingdom suggests that drinkers of black tea live a little longer than their peers who do not drink tea. And they live longer even if they add milk or sugar.
Researchers at the National Cancer Institute in the United States found that drinking two or more cups of tea daily lowered the risk of death from any cause by 9% to 13%. The observational analysis of a massive trove of data contained in the UK Biobank found the results held true regardless of diet, age, race, and gender. Findings were adjusted for risk factors, including health, wealth, coffee drinking, smoking, and drinking alcohol.
The study was published on August 30 in the Annals of Internal Medicine.
The Biobank contains in-depth genetic and health information on the most common life-threatening diseases. Participants in the study were aged 40–69 when they completed the baseline questionnaire distributed during 2006–2010. All participants received physical examinations and provided blood, urine, and saliva samples when enrolled. Study participants in 2022 averaged 56.5 years of age.
Participants recorded how many cups of tea they drank each day and whether it was hot, very hot, or cold. The majority (85%) said that they drink between two and five cups daily, while 19% reported drinking more than six cups per day. Black tea was favored by 89%. Portion size and strength were not assessed.
A follow-up at a median of 11 years revealed that 29,783 of the 498,000 participants had died.
Those who regularly drink tea experienced fewer incidents of heart disease (CVD), ischemic heart disease, and strokes. Maki Inoue-Choi, Ph.D., the study’s corresponding author, said that there was no evidence, however, that links tea consumption to a reduction in cancer deaths. The results were not different in tea drinkers who added milk or sugar. “Higher tea intake was modestly associated with lower all-cause mortality risk among those who drank two or more cups per day,” wrote Inoue-Choi, a researcher at the Metabolic Epidemiology Branch at the National Cancer Institute.
“While these findings may offer reassurance to tea drinkers, they do not indicate that people should start drinking tea or change their tea consumption for health benefits,” wrote Inoue-Choi. Instead, the findings “suggest that tea, even at higher levels of intake, can be part of a healthy diet,” according to Inoue-Choi.
Past research on the consumption of green tea has demonstrated health benefits such as reducing inflammation in the body, but few large-scale studies focus on black tea. Black tea contains theaflavins, thearubigins, and polyphenols that have been shown to have anti-inflammatory and antimicrobial properties and to control blood lipids.
Additional research is needed, because moderate tea drinkers were also found to smoke less, consume less red and processed meats, and drink tea at lower temperatures. Fernando Rodriguez Artalejo, professor of preventative medicine and public health at the University of Madrid, told Bloomberg News that the study does not address whether those who do not consume tea regularly would improve their health by drinking tea. Marion Nestle, a professor of food studies at New York University, wrote, “Observational studies like this always raise the question: Is there something else about tea drinkers that makes them healthier?” But, she advised, “a cautious interpretation seems like a good idea.”
Study: Inoue-Choi, M., et al. Tea Consumption and All-Cause and Cause-Specific Mortality in the UK Biobank: A Prospective Cohort Study. Annals of Internal Medicine. August 2022. DOI: 10.7326/M22-0041