An elderly couple holds hands and walks outside.
People with an upbeat outlook tend to use healthier coping styles to meet life’s challenges, according to one study. (For Spectrum Health Beat)

Women who generally believe that good things will happen may live longer.

That’s the suggestion of a new study that seems to affirm the power of positive thinking.

“This study shows that optimism is associated with reduced risk of death from stroke, respiratory disease, infection and cancer,” said Eric Kim, co-lead author of the investigation.

“Optimistic people tend to act in healthier ways. Studies show that optimistic people exercise more, eat healthier diets and have higher quality sleep,” said Kim, a research fellow in the department of social and behavioral sciences at Harvard T.H. Chan School of Public Health in Boston.

Kim added that an upbeat outlook also may directly affect biological function. Research has demonstrated that higher optimism is linked with lower inflammation, healthier lipid levels (fats in the blood), and higher antioxidants (substances that protect cells from damage), Kim said.

“Optimistic people also use healthier coping styles,” he said. “A summary of over 50 studies showed that when confronted with life challenges, optimists use healthier coping methods like acceptance of circumstances that cannot be changed, planning for further challenges, creating contingency plans, and seeking support from others when needed.”

For this investigation, scientists reviewed records on 70,000 women who participated in a long-running health study that surveyed them every two years between 2004 and 2012. The study authors examined optimism levels and other factors that might affect the results, such as race, high blood pressure, diet and physical activity.

Overall, the risk of dying from any disease analyzed in this study was almost 30 percent less among the most optimistic women compared to the least optimistic women.

For the most optimistic women, for instance, the risk of dying from cancer was 16 percent lower, the risk of dying from heart disease, stroke or respiratory disease was almost 40 percent lower, and the risk of dying from infection was 52 percent lower, the study found.

Levels of optimism were determined from responses to statements such as, “In uncertain times, I usually expect the best,” according to Kim.

While the study uncovered an association between optimism and life span, it did not prove cause and effect.

Dr. Sarah Samaan, a cardiologist at the Heart Hospital at Baylor in Plano, Texas, said healthy behaviors may help fuel optimism.

“It’s easier to feel optimistic when you feel healthy and energetic,” said Samaan, who was not involved in the research. “By choosing a healthy lifestyle, you may open yourself up to greater gratitude and create more energy for deeper relationships and professional satisfaction.”

She added that for people with depression and anxiety, medication may help to improve mental outlook and thus overall health, although this study did not address that specific issue.

The study authors noted that individual actions can promote optimism. The simple act of writing down best possible outcomes for careers, friendships and other areas of life could generate optimism and healthier futures, they suggested.

Kim described a two-week exercise where people were asked to write acts of kindness they performed that day. Another activity involved writing down things they were grateful for every day. Both these exercises were shown to increase optimism, he said.

The study was published online in the American Journal of Epidemiology.