Nov. 10, 2008 (New Orleans) -- If you're worried about your blood pressure, you may want to follow the British custom of regularly "sipping a cuppa" -- tea, that is.

In a new study, drinking three cups of herbal tea containing hibiscus each day lowered blood pressure.

"Most of the commercial herbal tea blends in the United States contain hibiscus," says Diane L. McKay, PhD, of Tufts University in Boston. She tells WebMD that people with the highest blood pressure at the start of the six-week study benefited the most.

McKay presented the study of 65 healthy men and women with modestly elevated blood pressure at the American Heart Association (AHA) meeting here.

Overall, drinking hibiscus tea blends lowered systolic blood pressure -- the top number in the blood pressure reading -- by an average of 7 points. That was significantly more than the 1-point drop observed in people who were given a placebo in the form of hibiscus-flavored water, McKay says.

While a 7-point drop in blood pressure might not seem like much, she says studies have shown that "even small changes in blood pressure ... when maintained over time ... will reduce the risk of stroke and heart attack."

Past AHA president Robert H. Eckel, MD, says that more study is needed to determine whether herbal tea's blood-pressure-lowering effect can actually be sustained over the long haul.

The degree of blood pressure lowering associated with tea drinking in the study was as much as would be expected with standard blood pressure drugs, he says.