Positivity may lead to a longer life, according to a study published Wednesday in the American Journal of Epidemiology.
The study, coauthored by Harvard research fellows Kaitlin Hagan and Eric Kim, examined the association between optimism and mortality in more than 70,000 women, Hagan said.
It found the most optimistic women in the group were 29 percent less likely to die of any cause between 2006 and 2012 than the least optimistic women, Hagan said.
A difference in death rates persisted when researchers focused on specific diseases, according to Hagan, who is also a fellow at Brigham and Women’s Hospital.
The most optimistic women were 38 percent less likely to die of cardiovascular disease in those years than the least optimistic women, and 16 percent less likely to die from cancer.
Findings in the blind study pointed to a correlation between optimism and lower mortality rates, but did not indicate whether optimism caused lower mortality rates. Hagan said they are still significant, however.
“We did account for many things. . . . People with more optimism have better health habits — they exercise more, eat better — and those things are attributed to lower mortality rates,” Hagan said. “Even accounting for those behaviors, they still have lower chances of death.”
Hagan and Kim used the Nurses’ Health Study, which was done on a group of 70,021 women who have been participating in a medical study since 1976, Hagan said. In 2004, when other studies began showing a possible link between optimism and lower rates of cardiovascular disease, the researchers decided to add an optimism component to the study.
Researchers gave the women a six-part questionnaire to measure their optimism, Hagan said. It gave them an assortment of positive and negative statements — such as, “In uncertain times, I usually expect the best,” or “If something can go wrong, it will” — and asked them how much they agreed with each statement.
Each woman was then placed into one of four categories based on their answers, which researchers used to follow their health outcomes, Hagan said.
There’s hope for those who don’t see the glass half full, too.
“The one thing people have asked is, ‘I’m not an optimistic person, is that something I should be worried about?’ ” Hagan said. “Other studies have shown you can increase your optimism. Optimism is something you can change.”
One easy method? Write down three things you’re grateful for every day, Hagan said.
Dylan McGuinness can be reached at dylan.mcguinness