Heart attack patients who are tea drinkers may survive longer than their peers who choose to consume a different type of beverage, researchers report.

Their study found that patients who drank the most tea were the least likely to die for up to 4 years regardless of their weight, smoking habits or history of diabetes and high blood pressure.

While it is not clear from the study why tea drinkers lived longer, the researchers speculate that flavonoids--potent antioxidants that are also found in apples, onions and broccoli--may playa key role. Previous studies have shown that these compounds are protective against heart disease.

But before doctors begin recommending that patients begin drinking more tea, more research is needed, the study's lead investigator Dr. Kenneth J. Mukamal of Harvard Medical School in Boston, Massachusetts, cautioned in an interview with Reuters Health.

"I don't believe everyone who has a heart attack needs to start drinking tea based on our study," he said. "However, our results add to a growing body of evidence that people with cardiovascular disease may benefit from tea consumption, and hopefully clinical trials will support that."

The study is published in the May 28th rapid access issue of Circulation: Journal of the American Heart Association.

The researchers interviewed 1,900 patients who had been hospitalized after a heart attack, over nearly 4 years. Patients reported their weekly caffeinated tea consumption during the year before their heart attack and were subsequently divided into three groups: those who did not drink tea, those who drank fewer than 14 cups of tea per week, and those who drank at least 14 cups of tea each week.

According to the results, three quarters of the roughly 300 deaths that occurred in the group were due to heart disease. Heavy tea drinkers--those who consumed about 19 cups of tea each week-- were 44% less likely to die than patients who did not drink tea, and moderate tea drinkers were 28% less likely to die for up to 4 years regardless of other medical and lifestyle factors.

The results of the study support previous research showing an association between black tea and endothelial function--the blood vessels' ability to relax--in individuals with heart disease. Studies have also demonstrated that flavonoids prevent LDL ("bad") cholesterol from oxidizing and sticking to the artery walls, and may prevent blood clots from forming. Mukamal and colleagues note.

More research is needed before recommendations can be made, since the investigators did not include detailed information about patients' overall diet, Mukamal added in an interview.