Having an optimistic outlook on life may do more than just boost your mood. It may actually help you live longer, according to new research from the Harvard T.H. Chan School of Public Health.
The study, published in the American Journal of Epidemiology, found that women who were optimistic had a significantly lower risk of dying from several major diseases, including cancer, heart disease, stroke, and respiratory disease, compared to other women whose outlook on life was less positive.
“Optimism in prior research has been shown to be related to better health behaviors and better health outcomes, particularly in cardiovascular disease,” postdoctoral research fellow Kaitlin Hagan, co-lead author of the study, told CBS News. “So in our study we wanted to expand that and look at all-cause mortality and be able to see whether optimism improves other health behaviors that then affects mortality, or whether there’s an independent effect of optimism on mortality.”
For the study, the researchers analyzed data on from 2004 to 2012 on 70,000 women who participated in the Nurses’ Health Study, a long-running research project tracking women’s health via surveys every two years.
To measure levels of optimism, participants were asked to use a five-point scale to either agree or disagree with six statements, such as, “In uncertain times, I usually expect the best.”
The results showed that the most optimistic women – those in the top 25 percent – had a nearly 30 percent lower risk of dying from any of the diseases analyzed in the study when compared to the least optimistic participants in the lowest 25 percent.
Specifically, the researchers found that the most optimistic women had:
- a 16 percent lower risk of dying from cancer.
- a 38 percent lower risk of dying from heart disease.
- a 39 percent lower risk of dying from stroke.
- a 38 percent lower risk of dying from respiratory disease.
The researchers controlled for a number of factors that could have had an impact on lifespan, including marital status, education level, and other socioeconomic factors.
While the study is observational and cannot prove a cause-and-effect relationship between optimism and a longer life, the researchers have some theories for what might be behind the connection.
“It’s a combination,” Hagan said. “If you’re more optimistic, you tend to have healthier behaviors. Optimistic people are likely to have better diets, they’re exercising more, and they’re getting better sleep.”
However, even after the researchers accounted for these factors, the results still suggest that optimism itself is linked to a longer life.
“So it could be that optimism directly impacts our biological functioning,” Hagan said. “Optimism is linked with lower inflammation and healthier biomarker levels and lipid levels, so there could be an independent effect on optimism.”
She said her team plans to focus more on the potential impact of optimism on biological functioning in future research.
The authors point out that since the study was only done in women, who were mainly white, the results might not be generalizable to other populations. However, they note, “there is no clear basis for believing that the effects of optimism on health differ by sex or race.”
Finally, the researchers emphasize that while some people may think they’re just not optimistic, it is something that is modifiable. They suggested a number of steps people can take to improve their level of optimism.
“One is called ‘best possible self,’” Eric Kim, who also co-led the study, told CBS News. “So you think about your different domains of life, whether it’s your personal relationship, your spouse, your career, your friendships, and in each of those domains you think about the best possible outcome.”
Hagan had some suggestions, too. “Simple things like thinking about what you’re grateful for every day or writing down what things make you happy or what things you’re looking forward to can help someone to increase their optimism, which can improve health outcomes as we’ve seen here,” she said.