Researchers suggest optimism may reduce women's risk of death from numerous medical conditions.
Co-lead author Eric Kim, of the Department of Social and Behavioral Sciences at Harvard T.H. Chan School of Public Health in Boston, MA, and colleagues say their findings suggest people should look at boosting their optimism as a way to improve health.
The researchers recently published their findings in the American Journal of Epidemiology.
Optimism is defined as a mental attitude characterized by positive thinking, whereby a person is hopeful and confident that good things will happen.
A number of studies have suggested that people who are optimistic tend to have better mental and physical health than those who are pessimistic - that is, those who have a negative outlook on life, always expecting the worst.
Research conducted by the University of Illinois last year, for example, found that optimists were twice as likely to have better heart health than their more pessimistic counterparts.
For the new study, Kim and colleagues set out to investigate whether having a positive outlook on life might influence the risk of death from various medical conditions.
Optimism reduced all-cause mortality by almost 30 percent
To reach their findings, the researchers analyzed 2004-2012 data from around 70,000 women who were part of the Nurses' Health Study - an ongoing project that assesses women's health through surveys conducted every 2 years.
Kim and colleagues looked at the self-reported optimism of each participant, as well as other factors that might contribute to mortality risk, such as high blood pressure, diet, and exercise.
Compared with women in the lowest quartile of optimism, those in the highest quartile of optimism were found to be nearly 30 percent less likely to die from all causes.
Looking at individual illnesses, the researchers found that women who were the most optimistic were 16 percent less likely to die from cancer, 38 percent less likely to die from heart disease, and 39 percent less likely to die from stroke, compared with women who were the least optimistic.
Additionally, women in the top quartile of optimism were at 38 percent lower risk of death from respiratory disease and were 52 percent less likely to die from infection, compared with those in the bottom quartile.
The researchers note that previous studies have linked optimism to reduced risk of cardiovascular death, but theirs is the first to associate the mental attitude with reduced mortality from other major illnesses.
'We should make efforts to boost optimism'
When accounting for healthy behaviors among participants, the team found that these could only partly explain the association between optimism and reduced mortality. With this in mind, Kim suggests it is possible that optimism may have a direct influence on our biological systems.
Based on their results, the authors say it might be worth focusing on ways to boost optimism as a means to good health.
"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.
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."