While inexperienced tea has a long-standing repute for well being advantages, analysis has been way more blended on black tea. One drawback, says Maki Inoue-Choi, an epidemiologist on the Nationwide Most cancers Institute, is that giant observational research on tea and mortality have targeted on international locations like Japan or China—locations the place inexperienced tea is extra fashionable.
To fill this hole, Inoue-Choi and her colleagues analyzed knowledge in the UK, the place black tea ingesting is frequent. After surveying about 500,000 folks and following them for a median of 11 years, the outcomes, printed Aug. 29 within the journal Annals of Inner 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—ingesting tea was related to a modestly decrease mortality danger for individuals 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 danger 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 completely a shock. In accordance 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 greater consumption of each black and inexperienced tea and biomarkers that predict cardiometabolic well being, together with decrease levels of cholesterol. Analysis has additionally instructed that tea may 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 diet sciences at George Washington College’s Milken Institute Faculty of Public Well being, who didn’t take part within the examine. One placing factor in regards to the new analysis, he notes, is that there isn’t an affiliation between rising the dose of tea—the quantity an individual consumes—and decreased mortality after the individual had consumed two or three cups. The exception, he stated, is for those who eradicate espresso drinkers, who might have made it tougher to identify an affiliation between rising the quantity of tea you drink and mortality as a result of they’d decrease mortality through the examine. With out the espresso drinkers, it turned clearer that ingesting tea was related to a decrease danger 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, nevertheless, that it’s best 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 selections, and should be replicated in randomized medical trials, specialists say. Plus, the magnitude of the affiliation between tea ingesting and mortality was modest, which implies it’s seemingly that one other attribute of people that drink tea may have led to this impact, says van Dam. As an illustration, individuals who drink tea may hypothetically have been much less more likely to devour tender drinks.
As Inoue-Choi put it, the brand new findings ought to be reassuring to individuals who drink tea commonly. However “folks shouldn’t change what number of cups of tea to drink day-after-day due to these outcomes,” she says.
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