(ABC News) - The average American's life expectancy is 78.7 years. Whether you reach that age—or better yet, exceed it—largely depends on your genes, but there are also many keys to longevity that are totally within your control. Some, you probably already know about, like following a nutritious diet, exercising often, staying away from cigarettes, and maintaining a healthy weight. Other habits are a little less obvious. Read on for some surprising habits and lifestyle choices that could add years to your life.
1. Adopt a furry friend
Your four-legged companion may be helping you live a longer life, according to a review published in the journal Circulation. Researchers believe owning a dog might keep the owner more active and, as a result, lowers the risk of heart disease.
"Dog owners are who walk their dogs are more likely to meet recommendations for daily physical activity (150 minutes weekly)," says Eric A. Goedereis, PhD, assistant professor of psychology at Webster University in St. Louis, MO. Owning a pet also reduces stress, which may decrease the risk of cardiovascular disease, he adds.
2. Have more sex
A roll in the hay may be the most pleasant way to extend your life. Several studies suggest there is a link between more orgasms and longevity. In a 1997 study, men who had more orgasms were less likely to die of heart disease than those who had less. While the study can't prove cause and effect (maybe healthier people are more likely to have sex), sex can be beneficial for health. "Of course sex feels good, but it also gives us the opportunity to work out nearly every muscle in the body and connect with another person," says Goedereis. "Sex has also been shown to boost the body's immune response, reduce stress, and even control one's appetite, among other things." Two to three orgasms a week yields best benefits. Doctor's orders.
3. Floss every day
Daily flossing not only gets rid of food trapped between your teeth but also removes the film of bacteria that forms before it has a chance to harden into plaque—something your toothbrush cannot do. Periodontal disease from lack of flossing can trigger low-grade inflammation, which increases the risk of early heart attack and stroke. Numerous studies link oral bacteria to cardiovascular disease. The American Dental Association recommends flossing at least once a day.
4. Have a positive attitude
Think being mean and ornery is what it takes to live to 100? That's what scientists at the Albert Einstein School of Medicine in the Bronx, New York thought until they studied 243 centenarians. When the researchers assessed their personalities, they discovered that most had a positive outlook on life, and were generally easygoing, optimistic, and full of laughter.
If nothing else, try to laugh more often—go to comedy shows, take occasional breaks at work to watch silly videos on YouTube, or spend time with people who make you smile. "Laughter helps decrease blood pressure, reduce blood sugars, dull pain, and lower stress, all of which can make your body healthier," says Elizabeth Lombardo, PhD, psychologist and author of Better than Perfect: 7 Strategies to Crush Your Inner Critic and Create a Life You Love.
5. Be social
Going to the movies or out for coffee with friends may help all of you grow old together. An analysis by Brigham Young University looked at data from 148 studies and found a clear connection between social ties and lifespan. "People with stronger social relationships have a 50% greater chance of continued living as compared to those with weaker relationships," says Lombardo. "Loneliness can also compromise your immune system, making it harder to fight off disease."
6. Go nuts
Snack on cashews, sprinkle chopped walnuts on your salad, stir almonds into your yogurt—however you eat them, it may be helpful. People whoate nuts several times a week had a reduced mortality risk compared with those who ate nuts less frequently (or at all), according to a 2013 study in a New England Journal of Medicine study.
Nuts are high in antioxidants, fiber, and unsaturated fatty acids, and they help lower your risk of heart disease. "They are known to possibly improve certain risk factors for diabetes as well," says Keri Gans, RD, a New York-based nutrition consultant. As a healthy but high-calorie snack, limit portion sizes to 1 ounce, or about 20 nuts.
7. Find your purpose
Regardless of your age, finding purpose in life may help you live long enough to make a difference. In a study of 6,000 people, researchers at the University of Rochester Medical Center in Rochester, New York found that people who had a greater sense of purpose were less likely to die during the 14-year study than those who were less focused on a goal. "People who have a sense of purpose in their lives may be more likely to take steps to be healthier," says Lombardo. To develop a sense of purpose, focus on the positive impact you are making at work or at home instead of getting caught up with every little detail being perfect, she suggests.
8. Start your mornings with coffee
Sipping a mug of coffee not only jumpstarts your day, but your longevity as well. Studies show coffee reduces the risk of a number of chronic diseases. "Drinking coffee may decrease your risk for diabetes, cardiovascular disease, and Alzheimer's disease," says Gans. Just go easy: too much caffeine can trigger anxiety and insomnia, or interfere with calcium absorption. And hold the whipped toppings—syrups and cream to avoid canceling out the health benefits.
9. Ditch soda
Even if you're not overweight, drinking soda may be shortening your lifespan, according to a study in the American Journal of Public Health. The five-year study found a link between soda intake and shortening of the telomeres, which are caps on the ends of chromosomes directly linked to aging. Telomeres shorten each time a cell divides and are thought to be an aging "clock." This study did not find the same link with diet soda, but other research has associated heavy diet soda drinking to weight gain, type 2 diabetes, and depression—all potential life-shorteners.