Scientific review published in Advances in Nutrition finds daily tea intake may lower the risk of cardiovascular disease and all-cause mortality
Around the world, the most popular beverage other than water is tea, with approximately 21% of Americans consuming tea every day. With so many regular tea drinkers, wouldn’t it be great if tea conferred health benefits?
Tea is a flavonoid-rich beverage. Flavonoids are a group of phytonutrients that are responsible for the colors in fruits and vegetables. A growing body of research suggests that flavonoids, as antioxidants, may offer healthful properties that protect us from heart disease and certain cancers. To date, research studies have examined the health properties of tea with mixed results, some finding a link between tea consumption and improved health outcomes and others not.
Recently published in Advances in Nutrition, the international review journal of the American Society for Nutrition, “Dose–Response Relation between Tea Consumption and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis of Population-Based Studies” reviewed the current body of evidence in order to determine the relation between tea consumption and the risk of cardiovascular disease and all-cause mortality.
In order to conduct their research, the authors of this review article searched the scientific literature for relevant studies, identifying 39 prospective cohort studies that met their criteria. Following their research, the authors concluded that “daily tea intake as part of a healthy habitual dietary pattern may be associated with lower risks of cardiovascular disease and all-cause mortality among adults.” Moreover, they stated that “incorporating tea as part of a healthy diet is a simple dietary modification that may have positive public health implications on chronic disease risk reduction worldwide.”
Several possible biological mechanisms may underlie the link between tea and a lower risk of cardiovascular disease. According to the authors, “the most important potential biological mechanism is the ability of tea flavonoids to reduce both systolic and diastolic blood pressure.”
Overall, the authors rate the strength of the evidence they collected to be low or moderate. Interestingly, the strength of the evidence was higher among studies that focused on older adults. The authors noted that “future, rigorously designed random-controlled trials would greatly strengthen the evidence base and certainty of our findings.” In particular, they pointed out that a lack of standardization across studies makes it difficult to determine the optimal dosage of tea.
Despite the call for more research, the authors believe “our systematic review provides evidence to begin developing dietary guidance and public health messaging around the consumption of tea.” If you’re currently a tea drinker, you can enjoy your next cup of tea with the knowledge that it likely confers positive health benefits. If you’re not currently a tea drinker, you might want to consider taking it up.
References Mei Chung, Naisi Zhao, Deena Wang, Marissa Shams-White, Micaela Karlsen, Aedín Cassidy, Mario Ferruzzi, Paul F Jacques, Elizabeth J Johnson, Taylor C Wallace, Dose–Response Relation between Tea Consumption and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis of Population-Based Studies. Advances in Nutrition, DOI: https://doi.org/10.1093/advances/nmaa010.
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