Death rates from heart attacks and strokes have decreased significantly since 1999 thanks to Americans exercising more, smoking less, improving their diets, and taking anti-cholesterol medications, Bloomberg News reported Dec. 15.

The U.S. Centers for Disease Control (CDC) reported a 31-percent drop in heart-attack deaths and a 29-percent decrease in stroke-deaths between 1999 and 2006. The decline was largely due to Americans adopting lifestyle changes that lower cholesterol and blood pressure, said Donald Lloyd-Jones, who authored the report and teaches preventative medicine at Northwestern University.

Half of the decrease in deaths can be attributed to advancements in cholesterol-lowering medication, according to the CDC's heart research team. If the decline continues, 240,000 lives could be saved by 2008, the report estimated.

"The goals set to be achieved by 2010 have been achieved four years early, and that's pretty terrific," Lloyd-Jones. "We might have done even better were it not for the obesity epidemic and the increases in diabetes that go along with that."

The researchers added that some risk factors for cardiovascular disease have increased, with two-thirds of people over the age of 18 saying they didn't engage in any physical activity; there also were increases in the number of overweight people in the U.S.

"We need to get much more serious about addressing the obesity epidemic," Lloyd-Jones said. "We might start to lose some ground unless we get serious about stopping obesity."

The report was released by the American Heart Association and published online in the journal Circulation.