About 69 million Americans are not as young at heart as they believe they are, the Centers for Disease Control and Prevention found.
Using a simple calculator that measures age, blood pressure and BMI, the CDC found that more than 40% of Americans had hearts that were five or more years older than their actual ages.
CDC Director Tom Frieden said that the heart risk calculator was simple way to reveal a person's risk of heart attack or stroke.
"Heart age is a understandable simple tool for people to understand their heart risk," Frieden said. "For every American, learning heart age can be a clear call to take charge of your health."
The analysis is the first study of its kind, examining more than a half-million adults between the ages of 30 and 74 who were part of the Framingham Heart Study.
Whose hearts are oldest?
Study authors found that while excess heart age increased as people were older, it also decreased with education and income.
When broken down by ethnicity, African-Americans had the oldest hearts. On average, the hearts of African-American men and women were about 11 years older than their actual ages. Hispanic men had hearts about eight years older than their biological ages and Hispanic women had hearts that were 5.9 years older. White men's hearts were 7.4 years older than their ages, and white women had the healthiest hearts, just 4.5 years older than their actual ages.
Women in their 30s, on average had heart ages that were just slightly younger than their actual ages. According to the CDC, 30% of Americans are at or below their heart age.
Where are the oldest and youngest hearts?
The South had the oldest hearts: 9.6 years older in Mississippi, 9.1 years older in Louisiana, 8.9 years older in Alabama and West Virginia. At the top of the list for youngest hearts were Utah, where hearts were 4.3 years older, and Colorado, where hearts were 4.6 years older.
How to prevent heart disease
By exercising regularly, watching diet and not smoking, people can do a lot to reduce their risk of heart disease and make their hearts younger. More than 75% of heart disease cases can be prevented with lifestyle changes. The CDC suggests following the ABCS -- aspirin when appropriate, blood pressure control, cholesterol management and smoking cessation.
It's not impossible to turn back the clock on your heart, Frieden said. "It's important to make your heart healthy as early as you can, but it's never impossible to reduce your heart age."
Smoking is one of the greatest culprits to heart aging, he said, and quitting smoking for a year would make a man's heart age 14 years younger.
Frieden said this simple calculator was a wakeup call for our health.
"Everyone deserves to be young at heart," he said, "or at least not old at heart."
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