Tea Helps Hearts Heal
Latest study adds to growing evidence the brew helps hearts recover from attacks
MONDAY, May 6, 2002 (HealthDayNews) -- Heavy tea drinkers -- whether they like it black, green, hot or cold -- are more likely to survive a heart attack than those who don't sip the healthy brew.
That's the finding of the latest study on a beverage that has been in the research limelight lately.
Scientists from Boston interviewed 1,900 people after their heart attacks, asking them to recall their consumption of caffeinated tea during the year before the attack.
"The more tea people drank, the lower the death rate," says lead author Dr. Kenneth Mukamal, an assistant professor of medicine at Harvard Medical School. The findings appear in tomorrow's issue of Circulation.
Moderate tea consumption, defined in the study as two cups a week, was associated with a 28 percent lower death rate when compared to the death rate of non-drinkers.
Heavy tea drinkers, who averaged 19 cups a week, fared even better: They had a 44 percent lower death rate than non-drinkers during the four-year follow- up. The average age of the heavy drinkers was 63, while the moderate and non-drinkers' average age was 61.
The most recent study follows a report, published last month in the American Journal of Clinical Nutrition, in which Dutch researchers found people who drank more than three cups of black tea a day had half the risk of having a heart attack when compared to non-drinkers -- and a third the risk of dying from a heart attack if they did suffer one.
In the latest study, tea drinkers had a lower death rate after their heart attacks, Mukamal says, regardless of their gender, age, smoking status or whether they had high blood pressure, were obese or had had a previous heart attack. The researchers took into account green or black tea, drunk hot or cold, but not herbal tea, he says.
They are certain it was not the caffeine in the tea that made the difference because they evaluated caffeine consumption from other foods and drinks consumed by the people, but found no effect on death rates from heart attacks.
How does tea help?
Mukamal suspects the tea's flavonoids, powerful antioxidants, help improve the blood vessels' ability to relax. Flavonoids also prevent the so-called bad cholesterol, or "LDL," from oxidizing, which experts believe may promote hardening of the arteries. The substances may also keep blood from clotting too much.
"A study like ours alone is not enough to advise people to change their [dietary] habits," Mukamal says. However, he also says he would not discourage anyone from drinking tea.
"There are no downsides. There is very good evidence that asking people to drink tea improves their blood vessels' ability to function normally, including the ability to relax," he says.
Other studies have shown that poor blood vessel function is associated with a higher risk for having a subsequent heart attack, he adds.
"I think it's a terrific study," says Jeffrey Blumberg, a professor of nutrition and chief of the Antioxidants Research Lab at the Jean Mayer USDA Human Nutrition Research Center on Aging in Boston.
Already, he says, "we have a body of evidence saying people who drink tea are less likely to get heart disease." Mukamal's study suggests people who already have heart disease can reap tea's benefits, too.
"Adding tea to your diet is certainly not harmful," Blumberg says. "It's got no calories, and it's got all those flavonoids. And it can be a [healthier] substitute for other beverages that we know do not have those compounds -- such as coffee or soda."
However, he adds that heart patients shouldn't think they can sip tea and skip other aspects of their diet. "It's not a panacea," he says.
"With each study like this, I become a little more confident that the effects of tea are real," he says.
What To Do
For more on heart health, see American Heart Association.
For information on tea, visit the Tea Association of the USA.