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/ Source: NBC News
By Maggie Fox

Americans value being young at heart, but most have hearts that are years older than their actual age, the Centers for Disease Control and Prevention says.

The average American man’s heart is eight years older than his chronological age, and the average U.S. woman’s heart is five years older.

That helps explain why so many Americans die early from heart attacks, strokes and heart failure, and why millions are on heart medication. Heart disease and stroke kill more than 800,000 people a year and are the leading cause of death in the United States.

“Your heart may be older than you are,” CDC director Dr. Thomas Frieden told reporters.

“In fact half of U.S. men and nearly half of U.S. women have a heart age that’s five years older than their chronological age.”

The CDC is pointing people to an online calculator they can use to calculate their own heart “age.”

It may be easier to use the calculator than other devices that give a person’s percentage risk of having a heart attack or stroke, the CDC said.

“It gives a stark, simple picture of your future risk of having or dying from a heart attack or a stroke,” Frieden said.

“Take for example a 53-year-old woman who finds out that her heart age is 22 years older than her chronological age: 75. And that’s because she smokes and has uncontrolled high blood pressure.”

The calculator includes all the basic factors that science has shown affect a person’s risk of heart disease: blood pressure, weight, blood sugar, cholesterol, age, sex and whether they have ever smoked.

“It has been shown to be a very good predictor of heart attack risk and stroke,” said Dr. Matthew Ritchey, a CDC heart disease expert.

To use it, people need to know their “top” blood pressure number, which should be under 120 for optimum health. They should know their body mass index (BMI), a calculation of height versus weight. (There’s a BMI calculator here.)

They also should know whether they have diabetes, and the calculator offers a more precise version if people know their cholesterol levels.

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The idea is to help people take charge and do something to turn it around, by stopping smoking, losing weight, eating healthier food, getting diabetes under control and exercising.

“For every American, learning your heart age can be a clear call for taking charge of your heart health,” Frieden said. People cannot control their age or sex, but they can control their weight and blood pressure as well as what they eat, how much they exercise and whether they smoke.

“About three in four heart attacks and strokes are due to risk factors that increase heart age, so it’s important to continue focusing on efforts to improve heart health and increase access to early and affordable detection and treatment resources nationwide,” said Barbara Bowman, director of CDC’s Division for Heart Disease and Stroke Prevention, whose team conducted the study.

The experts interviewed more than 500,000 people, asking about risk factors such as blood pressure, weight and cholesterol.

They plugged this information into a calculator called the Framingham heart calculator. It’s based on a decades-long, ongoing study of thousands of Americans whose health is followed in detail.

Chronologically, the men and women were just under 48 years old on average. But the men’s hearts more closely resembled the hearts of men almost 56 years old, and the women’s hearts looked more like 53-year-olds’.

People living in Utah tended to have the “youngest” hearts, while those in Mississippi, a state with a high burden of heart disease and obesity, had the “oldest,” at 10 years beyond chronological age, the team found.

Even younger Americans may have “old” hearts, Frieden said. The average American man in his 40s has a heart “age” that’s six years older than his chronological age, Frieden said.

“More than three in four heart attacks and strokes could be avoided or postponed if people manage or control their cardiovascular risk factors,” the CDC team said.

RELATED: Big bellies mean big heart disease risk

The calculator lets people figure out how to improve their odds.

“For example, a male smoker aged 50 years with untreated systolic blood pressure of 140 mm Hg, no diabetes, and a BMI of 30, has a predicted heart age of 72 years (74 years for a female with similar characteristics),” the CDC team wrote.

“Quitting smoking for one year alone would have reduced predicted heart age by 14 years (15 years for a woman), reducing systolic blood pressure to 120 mm Hg alone would have reduced predicted heart age by 6 years (10 years for a woman), and removing both risk factors would have lowered predicted heart age by 19 years (23 years for a woman).”