Are you satisfied with your life? Think carefully—the answer to this question may have an impact on how long you live. Previous research has shown that people who are happy tend to live longer. But researchers at Chapman University, the University of Kentucky and the Harvard School of Public Health wanted to know how the ups and downs in life—fluctuations in happiness—might make a difference in longevity.

The 2015 study followed 4,458 adults over a nine-year period; they were at least 50 years old when the study began. Once a year the participants were asked to rate their life satisfaction on a scale of 1 to 10, with 10 being the most satisfied. The researchers also tracked important health indicators such as whether or not they smoked, exercise, existing medical conditions and more.

Those at the higher end of the satisfaction scale had 18 percent lower mortality over the nine years.  “This actually has been shown in several studies in the past so this is really confirming previous research,” he says.

On the other hand, people whose life satisfaction fluctuated over the nine years saw a 20 percent increase in their mortality rate. The researchers noted that the satisfaction swings were especially impactful for people who didn’t have a high rate of life satisfaction to begin with. “This has to do more with who people are,. “If someone takes things really terribly one day and not so well the next it’s not as good as someone who is more at an even keel all the time.”

But can someone make changes to boost their life satisfaction—and increase their longevity? “Here we run into a big problem with a study like this,”  “What we’re really looking at is personality traits. I’m not completely convinced that this is something we can change in ourselves. Some people—things don’t bother them. They go along and do okay. For others, trying to change who you are may not be easy or even possible. And even if you do, whether that gives you the same mortality benefits as somebody who has been that way their whole life is up for grabs.”

While the study didn’t specify what’s meant by life satisfaction, it’s safe to say that managing your health by doing things like eating healthy and getting regular exercise can improve your outlook. Reducing stress—using time-honored techniques such as breathing exercises, yoga and meditation—can also make it easier to cope. Social connections add another piece to the puzzle. “One of the biggest ways we can reduce the harmful effects of stress is by talking to our loved ones, friends and relatives. “It’s really important. There’s no way to get around the fact that our lives are stressful.” And just knowing you don’t have to go it alone can make the ride a little less bumpy—and more satisfying.