Key Takeaways
- Studies have previously linked drinking green tea and coffee to reduced mortality risk in the general population.
- According to a new study, drinking these beverages may reduce mortality for stroke and heart attack survivors as well.
- Maintaining an overall healthy lifestyle is likely more effective at reducing mortality risk than incorporating green tea or coffee into your day-to-day.
Regular green tea and coffee consumption have previously been found to offer a myriad of health benefits, ranging from reducing the risk of cardiovascular disease to improving brain function. But now researchers suggest that the beverages can also reduce the risk of death for those who have experienced a stroke or heart attack.
Daily green tea consumption lowered stroke survivors’ death risk by 62%, and daily coffee consumption lowered heart attack survivors’ death rate by 22%, according to the study. The study’s findings were published in February in the journal Stroke.
“This study is an interesting large cohort study that finds that green tea and coffee consumption may have an association with mortality,” Barry Silverman, MD, an Atlanta-based cardiologist not involved in the study, tells Verywell.
The Findings
To conduct this study, researchers evaluated over 46,000 participants from 45 communities across Japan. After classifying participants into one of three groups—history of stroke, history of myocardial infarction (heart attack), or no history of stroke or heart attack—the researchers then examined the amount and frequency of green tea and coffee intake and evaluated any correlation in outcomes.
After data was analyzed, researchers found that stroke survivors who drank at least seven cups of green tea every day lowered their mortality risk by 62% when compared with those who did not drink tea consistently.
Heart attack survivors who had one cup of coffee every day lowered mortality risk by 22% when compared with those who did not have a daily cup of coffee. Subjects who did not have a history of stroke or heart attack and drank one or more cups of coffee a week had a 14% lower risk of overall mortality compared to non-coffee drinkers.
“I am not surprised by this study’s findings, primarily because we know that green tea has excellent benefits on two important components of cardiovascular health: reducing inflammation and improving blood vessel function,” Michelle Routhenstein, MS, RD, CDE, CDN cardiology dietitian and owner of Entirely Nourished, tells Verywell. “Many previous studies focused on high volumes of green tea consumption, whereas this study focused on the dose-response as well, confirming that any dose of green tea is still beneficial for heart health.”
While Silverman agrees that tea and coffee are likely not harmful to consume after a stroke or a heart attack, he is not convinced that it is necessarily helpful based on the current study.
“The study notes there is significant variation in diabetes, intake of fruits and vegetables, educational level, mental stress, and other factors, in addition, no physiologic mechanisms that is suggested for the benefit from the consumption,” Silverman says. “Drinking tea in Asian society and coffee in Western society is almost ubiquitous and may reflect as much on the personality, lifestyle, and character of the individual all of which are hard to define in a scientific study and which we understand may have a significant effect on cardiovascular morbidity and mortality.”
He says that the only generalization he can make is that green tea and coffee consumption do not appear to be harmful. “The mega numbers of the study I feel exclude harm, but there are too many other variables to prove the tea and coffee lower mortality,” he says.
What This Means For You
If you are a survivor of a stroke or heart attack, drinking coffee or green tea may help reduce your risk of death. But more research is needed before researchers can make a definite recommendation. Overall, maintaining a healthy lifestyle with regular exercise and healthy eating helps reduce your risk of death and disease.
Tea, Coffee, and Mortality
This is the first study to highlight the effects of coffee and tea on mortality outcomes for people who have experienced a stroke or heart attack. Previously, data has only been available on coffee and tea consumption’s effect on individuals without preexisting conditions.
In one study, also conducted on Japanese participants, over 300,000 people were evaluated on their green tea consumption frequency and mortality outcomes. Results showed when compared with individuals who consumed less than one cup of green tea per day, those who drank more than 5 cups per day had a decreased risk of overall mortality—especially for heart and cerebrovascular disease.
And in a meta-analysis evaluating 40 studies, coffee consumption appears to reduce all-cause mortality risk, when participants consumed a minimum of 3.5 cups of coffee a day.
Reducing Mortality Risk
According to the current data, drinking green tea and coffee may help reduce mortality risk in all people, including those who experienced a stroke or heart attack. But some key factors need to be kept in mind about the way these beverages are typically served in Japan, according to Hiroyasu Iso, MD, a professor of public health at Osaka University in Japan, and the study’s corresponding author:
- Green tea is often prepared with water and no added sugar
- Coffee is often served black, or with a small amount of sugar and milk
So, to reap the potential benefits, downing a double-mocha Frappuccino or a green tea latte loaded with sugar is not the best move. Pure green tea or coffee is your best bet.
If you enjoy coffee or tea, including it into an otherwise healthy diet will likely not cause any harm, and may do some good. Routhenstein suggests those who enjoy their green tea add a squeeze of lemon to their cup to “bump up the antioxidant content even further.”
If you experienced a heart attack or stroke, avoiding smoking, regular exercise, and healthy eating appear to help reduce the risk of death. Green tea and coffee can certainly be a part of that healthy routine. But until we have more data focused on green tea and coffee’s effect on mortality for stroke and heart attack survivors, don’t force yourself to down those drinks just yet if you’re not a coffee or tea lover.