People who have survived a heart attack or stroke would do well to try green tea or coffee. At least that’s what a new scientific study suggests, published on February 4 in the specialized journal Stroke.
“There is a strong need for scientific evidence on the lifestyles of stroke and heart attack survivors given the rapidly aging population and the need to improve life expectancy following these cardiovascular events” , said Dr Hiroyasu Iso, professor of public health at Osaka University, Japan, and co-author of the study.
The researchers analyzed data from more than 46,000 participants (aged 40 to 79, with a proportion of 60% women) of the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (or “JACC study”), a study conducted in 45 communities across Japan.
Participants were asked to complete questionnaires in order to find out about their lifestyle, medical history and eating habits. They were then divided into three groups: history of stroke, history of myocardial infarction, and no history of this type. The researchers then analyzed the amount and frequency of green tea and coffee consumption, considering that a cup of green tea contains around 100 ml and a cup of coffee 150 ml.
Verdict: Compared to participants who rarely drank green tea, stroke survivors who consumed at least seven cups of green tea per day had reduces their risk of all-cause mortality by approximately 62%. The researchers did not observe a statistically significant association among participants without a history of stroke or heart attack with regard to green tea. As for the participants with a history of heart attack, they had a risk of death reduced by about 22% if they drank one cup of coffee per day, compared to those who did not. Coffee would also be beneficial for people without a cardiovascular history, since those who consumed one or more cups of coffee per week had a risk of all-cause mortality reduced by 14% compared to non-coffee drinkers.
Important clarification, however: “in Japanese culture, green tea is usually brewed with water and no sugar. In addition, coffee is made with water and sometimes milk and sugar.”, Underlined Dr. Hiroyasu Iso. “The healthiest way to prepare these drinks is not to add sugar.”, He recalled.
Note that if the study does not say how tea and coffee decrease the risk of death, since it is only a correlation study, green tea and coffee are rich in polyphenols, antioxidants with many health benefits.