While inexperienced tea has a long-standing fame for well being advantages, analysis has been way more blended on black tea. One downside, says Maki Inoue-Choi, an epidemiologist on the Nationwide Most cancers Institute, is that enormous observational research on tea and mortality have targeted on international locations like Japan or China—locations the place inexperienced tea is extra common.
To fill this hole, Inoue-Choi and her colleagues analyzed knowledge in the UK, the place black tea consuming is widespread. After surveying about 500,000 individuals and following them for a median of 11 years, the outcomes, printed Aug. 29 within the journal Annals of Inside Medication, gave black tea a lift. Among the many inhabitants of tea drinkers—89% of whom drank black tea, in comparison with 7% who drank inexperienced—consuming tea was related to a modestly decrease mortality threat for many who had two or extra cups a day in comparison with non-drinkers. Individuals who added milk or sugar additionally skilled the profit, and the outcomes remained constant whatever the tea’s temperature. The findings additionally point out that tea drinkers had a decrease threat of dying from heart problems, ischemic coronary heart illness, and stroke than those that didn’t drink tea.
Whereas it’s troublesome to say why individuals who drink tea might reside longer, it’s not totally a shock. In line with Inoue-Choi, tea is “very wealthy in bioactive compounds” that scale back stress and irritation, together with polyphenols and flavonoids.
A 2020 examine that used the identical British database as the brand new analysis discovered that there’s an affiliation between increased consumption of each black and inexperienced tea and biomarkers that predict cardiometabolic well being, together with decrease levels of cholesterol. Analysis has additionally advised that tea might help decrease blood strain.
Going ahead, researchers ought to take a more in-depth have a look at the connection between tea and heart problems, says Rob M. van Dam, professor of train and vitamin sciences at George Washington College’s Milken Institute Faculty of Public Well being, who didn’t take part within the examine. One putting factor concerning the new analysis, he notes, is that there isn’t an affiliation between growing the dose of tea—the quantity an individual consumes—and decreased mortality after the particular person had consumed two or three cups. The exception, he stated, is should you eradicate espresso drinkers, who might have made it tougher to identify an affiliation between growing the quantity of tea you drink and mortality as a result of that they had decrease mortality through the examine. With out the espresso drinkers, it turned clearer that consuming tea was related to a decrease threat of dying of coronary heart illness. “The affiliation between tea consumption and cardiovascular mortality could also be driving the affiliation between tea consumption and all-cause mortality,” van Dam says.
None of that is to say, nonetheless, that you need to run to your kettle. The brand new analysis is predicated on an observational examine—which means that the proof wasn’t gathered from an experiment, and the outcomes had been inferred by the researchers. The findings shouldn’t be used to make well being choices, and should be replicated in randomized medical trials, consultants say. Plus, the magnitude of the affiliation between tea consuming and mortality was modest, which implies it’s seemingly that one other attribute of people that drink tea might have led to this impact, says van Dam. As an example, individuals who drink tea may hypothetically have been much less more likely to eat smooth drinks.
As Inoue-Choi put it, the brand new findings must be reassuring to individuals who drink tea frequently. However “individuals shouldn’t change what number of cups of tea to drink on daily basis due to these outcomes,” she says.
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