Want to Live to be 100? Check this out

Geoff Manasse / Photodisc file

Middle-aged people who run 40 minutes a day — for a total of about 5 hours per week — are more likely to live longer and function better physically and cognitively as they get older, according to researchers.

Prevention

You're the life of the party
Outgoing people are 50 percent less likely to develop dementia, according to a recent study of more than 500 men and women age 78 and older from the Karolinska Institutet in Sweden. Participants also described themselves as not easily stressed.

Researchers speculate that their more resilient brains may be due to lower levels of cortisol — studies show that oversecretion of this "stress hormone" can inhibit brain cells' communication. Science-backed ways to cut cortisol levels: Meditate, sip black tea, or take a nap.

You run for 40 minutes a day
Scientists in California found that middle-aged people who did just that — for a total of about 5 hours per week — lived longer and functioned better physically and cognitively as they got older; the researchers tracked runners and nonrunners for 21 years.

"What surprised us is that the runners didn't just get less heart disease — they also developed fewer cases of cancer, neurologic diseases, and infections," says study author Eliza Chakravarty, MD, an assistant professor of medicine at Stanford University School of Medicine. "Aerobic exercise keeps the immune system young." If you don't like to run, even 20 minutes a day of any activity that leaves you breathless can boost your health, she says.

You like raspberries in your oatmeal
Most Americans eat 14 to 17 g of fiber per day; add just 10 g and reduce your risk of dying from heart disease by 17 percent, according to a Netherlands study. Dietary fiber helps reduce total and LDL ("bad") cholesterol, improve insulin sensitivity, and boost weight loss. One easy fix: Top your oatmeal (½ cup dry has 4 g fiber) with 1 cup of raspberries (8 g) and you get 12 g of fiber in just one meal.

Try some of these other potent fiber-rich foods: ½ cup of 100 percent bran cereal (8.8 g), ½ cup of cooked lentils (7.8 g), ½ cup of cooked black beans (7.5 g), one medium sweet potato (4.8 g), one small pear (4.3 g).

You feel 13 years younger than you are
That's what older people in good health said in a recent survey of more than 500 men and women age 70 and older. "Feeling youthful is linked to better health and a longer life," says researcher Jacqui Smith, PhD, professor of psychology at the University of Michigan. "It can improve optimism and motivation to overcome challenges, which helps reduce stress and boost your immune system and ultimately lowers your risk of disease."

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, MD, 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, MD, PhD, 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. To find out how many calories you need to maintain a healthy weight, go to prevention.com/caloriecalculator.

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, PhD, 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, MD, 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 3 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 have a (relatively) flat belly after menopause
Women who are too round in the middle are 20 percent more likely to die sooner (even if their body mass index is normal), according to a National Institute on Aging study. At midlife, it takes more effort to keep waists trim because shifting hormones cause most extra weight to settle in the middle. If your waist measures 35 inches or more (for men, 40 inches or more), take these steps:

1. Work two or three 20-minute strength-training sessions into your weekly exercise regimen to preserve lean muscle mass and rev metabolism.

2. Eat a daily serving of omega-3s to help combat inflammation and seven daily servings of fruits and vegetables, loaded with disease-fighting antioxidants.

3. Get 25 percent of your daily calories from healthy fats — such as monounsaturated fatty acids — which protect your heart and may help you store less fat in your belly (for a 1,600-calorie diet, that's 44 g).

You get your blood tested for vitamin D levels
For optimal disease protection, we need at least 30 nanograms of vitamin D per milliliter of blood, reports a study in the Archives of Internal Medicine. Nearly 80 percent of Americans have less than that. Vitamin D not only helps bones ward off osteoporosis but may also reduce your risk of cancer, heart disease, and infection, says lead researcher Adit A. Ginde, MD, MPH, an assistant professor of surgery at the University of Colorado Denver School of Medicine. If needed, you can take a daily supplement to get your numbers up. Doctors can measure your levels with a simple blood test, but periodic monitoring may be necessary — vitamin D turns toxic at 100 to 150 ng/mL.