12 Surprising Signs You'll Live to 100 [7-12]

You had a baby later in life.

If you got pregnant naturally after age 44, you're about 15 percent less likely to die during any year after age 50 than your friends who had their babies before age 40, reports a recent University of Utah study. "If your ovaries are healthy and you are capable of having children at that age, that's a marker that you have genes operating that will help you live longer," says lead researcher Ken R. Smith, Ph.D., professor of human development at the university.

Your pulse beats 15 times in 15 seconds.

That equates to 60 beats per minute—or how many times a healthy heart beats at rest. Most people have resting rates between 60 and 100 bpm, though the closer to the lower end of the spectrum, the healthier. A slower pulse means your heart doesn't have to work as hard and could last longer, says Leslie Cho, M.D., director of the Women's Cardiovascular Center at the Cleveland Clinic.

You don't snore.

Snoring is a major sign of obstructive sleep apnea, a disorder that causes you to stop breathing briefly because throat tissue collapses and blocks your airway. In severe cases, this can happen 60 to 70 times per hour. Sleep apnea can cause high blood pressure, memory problems, weight gain, and depression. An 18-year study found that people without OSA were three times more likely to live longer than those with severe apnea. If you snore and have excessive daytime drowsiness or mood changes, talk with your doctor about a referral to a sleep center.

You embrace techie trends.

Learn to Twitter or Skype to help keep brain cells young and healthy, says Sherri Snelling, senior director for Evercare (part of United-Healthcare), a group that sponsors an annual poll of U.S. centenarians. Many of the oldest Americans send e-mails, Google lost friends, and even date online. Researchers say using the latest technology helps keep us not only mentally spry but socially engaged: "Stay connected to friends, family, and current events, and you feel vital and relevant," says Snelling.

You started menopause after age 52.

Studies show that naturally experiencing it later can mean an increased life span. One reason: "Women who go through menopause late have a much lower risk of heart disease," says Mary Jane Minkin, M.D., clinical professor of obstetrics and gynecology at Yale University School of Medicine.

You make every calorie count.

Researchers in St. Louis reported that men and women who limited their daily calories to 1,400 to 2,000 (about 25 percent fewer calories than those who followed a typical 2,000-to 3,000-calorie Western diet) were literally young at heart—their hearts functioned like those of people 15 years younger. "It's about not just eating less but getting the most nutrition per calorie," says study author Luigi Fontana, M.D., Ph.D., associate professor of medicine at Washington University School of Medicine. Study subjects stuck to vegetables, whole grains, fat-free milk, and lean meat and nixed white bread, soda, and candy. If you cut empty calories and eat more nutrient-rich foods, your health will improve, says Fontana.