Moderate black tea consumption connected to lower mortality rate, says study

30 Aug 2022 --- People who drink two cups of black tea per day have a 9% to 13% lower risk of an early death than non-tea consumers, according to a study from the US National Cancer Institute.

The research found that UK consumers who drink two cups of black tea per day have a nine to 13% lower risk of an early death than non-tea consumers. 

Drinking tea, in any amount, leads to lower risks of cardiovascular disease and stroke in participants, independently of how they consumed their tea – participants that drank coffee or added milk or sugar also had lower mortality rates.

“Higher tea intake was associated with lower mortality risk among those drinking two or more cups per day, regardless of genetic variation in caffeine metabolism. These findings suggest that tea, even at higher levels of intake, can be part of a healthy diet,” according to the study authors.

Study methodology
The observational study was conducted by researching the habits of 498,043 men and women aged 40 to 69 who initially completed a baseline questionnaire from 2006 to 2010. Participants were followed for about 11 years.

Of the participants, 85% drank tea regularly, and nine out of ten reported drinking black tea.

According to the US Department of Health and Human Services, past studies on tea consumption mainly focused on Asian populations, who commonly drink green tea, with studies on black tea yielding mixed results.

However, the study is not conclusive on the positive effects of tea consumption, as there could be other factors in people that drink tea that are the influencers of disease risk.

Previous studies focused on green tea consumption.

Previous studies

In 2021, a Chinese study using 365,682 participants revealed that moderate consumption of tea and coffee or in combination was associated with lower risks of stroke and dementia.

The research carried out by Tianjin Medical University, China, revealed that individuals who drank two to three cups of tea daily had a 32% lower risk of stroke. There was also a 28% lower risk of dementia compared with those who drank neither coffee or tea.

A previous Chinese study found that habitual tea drinkers who maintained their habit in both surveys found that people who drank tea more than three times a week had a 39% lower risk of incident heart disease and stroke, 56% lower risk of fatal heart disease and stroke and 29% decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.

Green tea can aid with type 2 diabetes
Another research performed by the University of Penn State in collaboration with Ohio State University, published in June, revealed that consuming green tea extracts for four weeks can reduce blood sugar levels. 

Furthermore, it found that green tea reduces gut inflammation and decreases gut permeability.

A clinical trial performed on 21 adults diagnosed with a precursor to type 2 diabetes found that they showed significantly lower blood glucose levels after consuming a tea extract – containing the equivalent of five cups of tea – than a control group taking a placebo.

“We did not attempt to cure metabolic syndrome with a one-month study,” says professor Richard Bruno, professor of human nutrition at Ohio State University.

“But based on what we know about the causal factors behind metabolic syndrome, there is potential for green tea to be acting at least in part at the gut level to alleviate the risk for either developing it or reversing it if you already have metabolic syndrome,” he concludes.

By Marc Cervera