During that time, women who ranked in the top quarter for optimism had a 29 percent lower risk of dying from any cause during the follow-up period, compared with those in the bottom quarter. Specifically, they had a 52 percent lower risk of dying from infection, a 39 percent lower risk of dying from stroke, a 38 percent lower risk of dying from heart or respiratory disease, and a 16 percent lower risk of dying from cancer.
“While most medical and public health efforts today focus on reducing risk factors for diseases, evidence has been mounting that enhancing psychological resilience may also make a difference,” said co-lead author Eric Kim, PhD, research fellow at the Harvard T.H. Chan School of Public Health, in a press release. “Our new findings suggest that we should make efforts to boost optimism, which has been shown to be associated with healthier behaviors and healthier ways of coping with life challenges.”
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This study was not able to prove a cause-and-effect relationship, and of course it would make sense that healthier people might also be more optimistic—or that optimistic people would take better overall care of themselves. But the researchers controlled for these scenarios as much as possible, by excluding participants who had an illness at the start of the study, or who died within the first two years.
And even after controlling for health conditions, depression, and healthy behaviors—such as eating a healthy diet, exercising regularly, and not drinking excessively or smoking—the most optimistic women still had a 9 percent reduced risk of dying, compared to the least optimistic.
This suggests that, in addition to encouraging healthy behaviors, optimism may directly affect our biology, says Kim. Exactly how is unclear—but previous studies offer some potential clues, suggesting that the trait is associated with benefits such as healthier cholesterol, lower levels of inflammation, stronger immunity, and a slower rate of cellular aging.
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Perhaps the best news is that optimism is something we can all practice. Even if you’re naturally a glass half-empty type of person, studies show that a positive mindset can be learned and cultivated through relatively simple exercises.
One example could be “having people write down and think about the best possible outcomes for various areas of their lives, such as careers or friendships,” says co-lead author and research fellow Kaitlin Hagan, PhD. “Encouraging use of these interventions could be an innovative way to enhance health in the future.”