Tea may reduce risk of death after heart attack

BOSTON, Massachusetts (CNN) -- Drinking at least two cups of tea a day may dramatically reduce a person's chances of dying following a heart attack, a study suggests.

Researchers said they suspect properties found in black and green tea may be protecting the heart.

"The results were more dramatic than I anticipated," said Dr. Kenneth Mukamal, who led the study, which was published Monday in the American Heart Association's journal, Circulation.

"Even if the true effect of tea is less than what we found, it could still make a sizable difference in heart attack survival."

The heavy tea drinkers in the study -- those who drank two or more cups of tea a day -- had a 44 percent lower death rate following their heart attack, compared with nondrinkers. The study found even a benefit in moderate tea drinkers. Those who drank fewer than 14 cups a week had a 28 percent lower death rate.

In the study, researchers asked 1,900 heart attack survivors about their tea consumption before their heart problem and followed them for up to four years.

"The most important outcome after a heart attack is whether they lived or died," said Mukamal of Beth Israel Deaconess Medical Center in Boston. "This is a high-risk group of people who are prone to another heart attack or other heart events. To imagine that tea might lower this risk is very exciting."

Researchers said there's good reason to believe it's the flavonoids -- antioxidants found naturally in various foods derived from plants -- that are protecting the heart by relaxing the blood vessels so blood can flow more easily. There's also evidence to suggest flavonoids may prevent LDL cholesterol -- the so-called bad cholesterol -- from becoming really bad cholesterol.

So, should everyone start drinking tea to avoid death after a heart attack?

Mukamal isn't making that recommendation yet.

"Those who've had a heart attack and have been worried about caffeine in tea should be reassured," he said.

The study did not ask patients about decaffeinated tea use, but Mukamal said there's no reason to believe caffeine makes a difference in the benefit. However, herbal teas would not provide the same benefits since the chemical makeup is different than that found in black tea and green tea.

Dark beer, wine and whiskey also contain flavonoids but in amounts lower than that found in tea.

"Ultimately I hope this work will spur on more research so we can find out the exact effect of tea on the heart," Mukamal said, "so one day we could give a tea prescription, along with aspirin and other medications following a heart attack. It seems there are no downsides to drinking tea."