Study: Drinking green tea linked to longer, healthier life
By: Team Ifairer | Posted: 17-01-2020
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"Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect," said Gu. In a subanalysis by type of tea, drinking green tea was linked with about 25 per cent lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death, the researchers said. However, no significant associations were observed for black tea, they said. Gu noted that a preference for green tea is unique to East Asia.
"In our study population, 49 per cent of habitual tea drinkers consumed green tea most frequently, while only 8 per cent preferred black tea. "The small proportion of habitual black tea drinkers might make it more difficult to observe robust associations, but our findings hint at a differential effect between tea types," he said. Two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors including high blood pressure and dyslipidaemia. Black tea is fully fermented and during this process, polyphenols are oxidised into pigments and may lose their antioxidant effects.
Second, black tea is often served with milk, which previous research has shown may counteract the favourable health effects of tea on vascular function. Gender-specific analyses showed that the protective effects of habitual tea consumption were pronounced and robust across different outcomes for men, but only modest for women. "One reason might be that 48 per cent of men were habitual tea consumers compared to just 20 per cent of women."Secondly, women had a much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men," Wang said.