The potential health benefits of tea have been widely studied, and some research suggests that drinking tea may help fight cancer and cardiovascular disease (heart disease and stroke). Tea contains antioxidants—chemicals derived from plants that are also found in a variety of fruits, vegetables, grains, legumes, and nuts. Antioxidants help fight disease by protecting the body's cells from damage.

Now, research recently published in Circulation: Journal of the American Heart Association suggests that regular tea drinkers may be more likely to survive a heart attack than those who don’t drink tea.

About the study

Researchers from Harvard School of Public Health and two Boston hospitals studied 1900 patients enrolled in the Determinants of Myocardial Infarction Onset Study. Patients in this study were men and women (average age 62) who had suffered a heart attack between 1989 and 1994.

Patients were interviewed an average of four days after their heart attack by a trained interviewer using a structured questionnaire. The following information was collected:

  • Weekly consumption of caffeinated tea during the year before the heart attack
  • Medical history
  • Medication use, particularly aspirin
  • Height and weight (body mass index – BMI)
  • Other medical conditions: stroke, respiratory disease, kidney disease, and cancer
  • Complications of the heart attack
  • Non-tea caffeine consumption

The researchers identified which patients died up through December 31, 1995 by searching the National Death Index and reviewing their death certificates. After an average of nearly four years of follow-up, the researchers compared the number of deaths among tea drinkers with the number of deaths among nondrinkers.

The findings

Heavy tea drinkers (14 or more cups per week) were about 45% less likely to have died of cardiovascular causes during the study period than nondrinkers. In addition, moderate tea drinkers (less than 14 cups per week) were 28% less likely to have died of cardiovascular causes than nondrinkers.

In calculating these statistics, the researchers accounted for factors such as age, sex, previous heart attack, diabetes, high blood pressure, use of cholesterol medication, smoking, alcohol, BMI, and aspirin use.

Although these results are interesting, there are some limitations to this study.

As with any study that relies on participants to recall their eating or drinking habits, the accuracy of their recall is uncertain. Because the researchers did not collect information on types of tea (for example, black tea or green tea), it is unclear whether all or only certain types of tea provide this benefit. Although the researchers based this study on the effects of caffeinated tea, respondents could have misidentified decaffeinated tea as being caffeinated. It’s also unclear, for the purposes of this study, how much tea constitutes a cup. A mug of tea (12 oz) holds two times the amount of tea as a typical teacup (5.5 to 6 oz), which could affect the conclusions of the study.

In addition, the role of other dietary factors, such as fruits, vegetables and fat, is unknown because information on other dietary habits was not collected. Finally, this study was conducted in people who survived their heart attack long enough to be interviewed several days later, so it provides no information about the tea-drinking habits of those who died immediately as a result of their heart attacks.

How does this affect you?

If you’re not a tea drinker, should you start? Sure. Although this study is the first to suggest that drinking caffeinated tea may help you survive a heart attack, it also supports the findings of other studies that tea may be good for overall heart health. In addition, other research has shown that black and green teas may help reduce the risk of some forms of cancer and can help lower cholesterol levels.

Although a nice cup of tea is a good source of antioxidants, you can also find antioxidants in fruits, vegetables, grains, nuts, and legumes (beans and peas).