While coffee and soda tend to be the beverages of choice in America, tea is the most popular beverage worldwide, after water. The three most popular types of tea are green, oolong, and black. Green tea has been studied extensively for its health benefits. Laboratory and animal studies suggest that green tea might protect against cancer and cardiovascular disease (CVD). But it is not clear whether the beverage actually protects against these diseases in humans.

In an article published in the September 13, 2006 Journal of the American Medical Association , researchers studied the effects of green tea consumption on death from any cause, death from CVD, and death from cancer. They found that people who drank the most green tea were significantly less likely to die from all causes and CVD than those who drank the least green tea. However, green tea consumption had no effect on the rates of cancer death.

About the Study

The researchers collected data from 40,530 adults, ages 40-79 years old, who lived in northeastern Japan and had no history of cancer, heart attack , or stroke . The study participants answered questionnaires that asked how often they drank green tea (less than 1 cup per day; 1-2 cups per day; 3-4 cups per day; or five or more cups per day). They also answered questions about other food and beverage consumption; alcohol and tobacco use; family medical history; and other social, demographic, and lifestyle factors. The researchers followed the participants, noting deaths from any cause for eleven years and deaths due to cancer or cardiovascular disease for seven years.

The risk of death from any cause and from CVD decreased as the amount of green tea consumed per day increased. Participants who drank five or more cups of green tea per day were 16% less likely to die from any cause and 26% less likely to die from cardiovascular disease than participants who drank less than one cup of green tea per day. These were significant differences, and they held true even after the researchers took other relevant factors, such as body mass index, activity level, smoking status, and other dietary factors into consideration. Green tea consumption did not affect the risk of death from cancer.

This was an observational study, which allowed researchers to establish an association between green tea and mortality. However, clinical trials are needed to test whether a cause and effect relationship exists between the two.

How Does This Affect You?

This study found that adults who drank five or more cups of green tea per day were significantly less likely to die of cardiovascular disease or from any cause compared to adults who drank less than one cup of green tea per day.

Tea is the most commonly consumed beverage in the world, after water. And though it hasn’t traditionally been as popular in the United States, tea has gained some popularity here in recent years. Bottled and boxed green teas, which are available caffeinated and decaffeinated, are available in grocery stores. And tea is often on the menu in restaurants and even coffee bars.

If you’re looking for a substitute for all that soda or coffee you’re drinking, consider a hot or iced glass of green tea. You might enjoy a change from the usual—and possibly some health benefits as well.