16 Unexpected Ways to Add Years to Your Life

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.

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.

Related:12 Ways Pets Improve Your Health

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.

Related:13 Healthy Reasons to Have More Sex

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.

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.

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."

Snack on cashews, sprinkle chopped walnuts on your salad, stir almonds into your yogurt—however you eat them, it may be helpful. People who ate 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.

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.

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.

Quality of sleep also plays in role in how long you may live. Multiple studies have linked sleep deprivation with an increased risk of death, and other research has shown that a lack of shuteye may raise risk of type 2 diabetes. "Some people may need more or less sleep than others, but research suggests that seven hours is probably enough," says Goedereis. To sleep soundly, establish a nighttime routine and stick to a schedule, even on weekends.

An Illinois study found clear evidence that happy people experience better health and live longer than their unhappy peers. "Depression, pessimism, and stress predict shorter lifespans," says Lombardo. "These mental states tend to cause a stress reaction within the body, which can weaken the immune system. Happiness, on the other hand, tends to result in less stress hormones." Take time to experience gratitude every day. "It's one of the quickest and longest-lasting ways to boost happiness," she adds.

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.

Drinking a little less than one glass of wine a day is linked to a lower rate of cardiovascular death from all causes when compared to abstaining from all alcohol, according to a Dutch study. Researchers found that light alcohol consumption resulted in longer life expectancy at age 50. Drinking less than or equal to 20 grams per day of alcohol (that's a little less than a serving of beer, wine, or spirits) was associated with a 36% lower risk of all causes of death and a 34% lower risk of cardiovascular death. And sorry, beer and cocktail fans: the same results were not found with light-to-moderate alcohol intake of other types.

No need to run for an hour a day to reap the life-lengthening benefits. A new study shows running just 5 to 10 minutes a day increases your life expectancy by reducing the risk of death from heart disease by 58% and dropping the overall risk of death by 28%. It holds true even if you're a slowpoke. Those who ran at less than 6 miles per hour only once or twice a week experienced clear benefits, the researchers reported in the Journal of the American College of Cardiology. Researchers credit better lung and heart function with the extended lifespan. Consistency works best, however: Exercisers who ran regularly for an average of six years reaped the greatest benefits.

A diet heavy in omega-3-rich foods may add years to your life, says a study from the Annals of Internal Medicine. In the study of more than 2,600 adults, those with the highest blood levels of omega-3 fatty acids—found in salmon, albacore tuna, mackerel, and lake trout—lived more than two years longer on average than those with lower blood levels. The study didn't prove that being a fish-eater increases longevity, but suggests a connection. Researchers found that people with high omega-3 levels reduced their overall risk of death by any cause by up to 27% compared to those with the lowest levels, and that they had a 35% lower risk of dying from heart disease. Experts recommend at least two 3.5-ounce servings of fish a week.

Simply stand up more during the day and you'll boost your longevity by increasing the length of your telomeres, according to a study from the British Journal of Sports Medicine. The study measured the effects of sitting time and physical activity among 49 sedentary, overweight participants. Researchers found increased telomere length—end caps of chromosomes that link directly to longevity—in the red blood cells of individuals participating in a 6-month physical activity intervention.

Helping others not only feels good, it may help you live longer, too. A review of data from 40 published papers found a 20% lower risk of death than non-volunteers. The findings, published in the journal BMC Public Health, found that those who volunteered experienced lower levels of depression, better life satisfaction, and overall enhanced wellbeing. Another study found that retirees who volunteered at least 200 hours in the prior year were less likely to develop high blood pressure than non-volunteers, lowering their risk of heart disease. Lend a hand for a win-win result.