A new report from doctors in China has found that regular tea consumption is linked to more healthy years of life and a longer life span. Individuals who drank tea more than three times a week cut their risk of heart disease and stroke by 20 percent compared with those who didn’t regularly drink tea or never consumed it, according to the study, which was published this week in the European Journal of Preventive Cardiology. Habitual tea drinkers also reduced their chances of dying from heart disease or stroke by 22 percent. Their odds of dying from any cause were lower by 15 percent. The type of tea you drink, however, may make a difference. Subanalysis revealed that drinking green tea was related to about a 25 percent lower risk of heart disease and stroke, fatal heart disease and stroke, and all-cause death. Although scientists observed similar protective effects against cardiovascular disease and all-cause mortality among those drinking scented tea and black tea, the results were not significant enough to make any definite conclusions. RELATED: 10 Potential Health Benefits of Green Tea Backed by Science “The most exciting finding for us was that adherence to the tea drinking habit for a long term could strengthen the health benefit of tea,” says the study author Dongfeng Gu, MD, of the department of epidemiology at the Chinese Academy of Medical Sciences and Peking Union Medical College in Beijing. The risk of cardiovascular disease was 40 percent lower among the 4,267 participants who kept up with regular tea drinking for at least eight years, according to Dr. Gu. These long-term tea imbibers also had a 56 percent lower risk of fatal heart disease and stroke and a 29 percent decreased risk of all-cause death compared with never or nonhabitual tea drinkers. Gu and his fellow researchers based their findings on an analysis of 100,902 participants who had no history of heart attack, stroke, or cancer. Over an average follow-up period of about seven years, 3,683 experienced atherosclerotic cardiovascular disease events (such as stroke and heart attack), and 1,477 died from these events. A total of 5,479 died from any cause. To illustrate how tea drinking can improve health, investigators estimated that a 50-year-old habitual tea drinker would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than a person who never or seldom drank tea.
Why Might Green Tea Be So Good for You?
Sarah Samaan, MD, a cardiologist with Baylor Scott & White Legacy Heart Center in Plano, Texas, points out that this report meshes well with other research suggesting a protective effect of tea on heart health. “Tea is a rich source of powerful antioxidants, which have known benefits for heart and vascular health, including protecting the arteries from inflammation and stress, and lowering blood pressure,” says Dr. Samaan, who was not involved in the research. “Green tea in particular is more potent because it is less processed than black tea, so more of these beneficial substances are available in the finished product.” Guy Mintz, MD, the director of cardiovascular health and lipidology at Northwell Health’s Sandra Atlas Bass Heart Hospital in Manhasset, New York, adds that green tea has bioactive compounds including flavonoids, such as catechins, and polyphenols, all of which have been associated with significant cardiovascular benefit. Polyphenols are also found in olive oil, cocoa, and red wine. “The known benefits associated with these polyphenols and flavonoids are anti-inflammatory,” say Dr. Mintz, who was also not a study investigator. “This leads to improvement of the blood vessel function with more dilation and less constriction, improvement in cardiac cell function, an increase in our HDL [good cholesterol], improvement in blood pressure, reduction in various markers of inflammation [such as C-reactive protein and interleukin-6], and making one of our clotting factors — platelets — less sticky.”
Don’t Rule Out the Potential of Black Tea
The study authors suggest a few reasons why black tea may not have produced significant health outcomes in those who regularly enjoy the beverage. For one, black tea goes through a fermentation that oxidizes the polyphenols, stripping them of their beneficial antioxidant effect, according to scientists. Also, investigators indicate that black tea is often served with milk, which may counteract the positives of tea on vascular function. In addition, the fact that the research was conducted in China may have skewed the results. Almost half the habitual tea drinkers in the study consumed green tea most frequently, while only 8 percent preferred black tea. The small proportion of habitual black tea drinkers might make it more difficult to observe robust associations, argues Gu. “Black tea is popular in European countries and was found to be associated with reduced risks of stroke and coronary artery disease in the Netherlands, Finland, and Sweden,” he says. Coffee may also offer a similar health lift, adds Samaan. “Studies of coffee have also found evidence of heart protection that is likely also related to the antioxidants in the coffee beans,” she says.
Differences for Men and Women
Compared with their female counterparts, male study participants appeared to get a bigger health boost from tea. One reason might be that the proportion of habitual tea consumers among men was approximately two and a half times as high compared with women. Secondly, women usually have a lower incidence and mortality of heart disease in China and East Asian countries, according to Gu. “These differences made it more likely to find robust results among men but not women statistically,” he says. Mintz stresses that future studies with a greater number of women represented in both groups are needed to look for any gender benefit. Because this investigation was not a randomized controlled trial, other significant factors may not have been accounted for and evaluated. “Diet, lifestyle, and genetic risk factors may all play a role in determining how tea is used by the body,” says Samaan. Mintz would like to see future research testing flavonoids and polyphenols alone. If they are concentrated and provided as a supplement, would they produce similar results? Gu agrees that research should dig deeper into the mechanism behind tea’s positive power. “Further study needs to identify the causal role of tea intake using randomized controlled trials in the future,” he says.
