A recent PNAS paper describes how the researchers assessed the link between higher optimism and longer lifespan, with a particular focus on the chances of reaching “exceptional longevity.”
The team carried out the study because most research on exceptional longevity has tended to focus on the effect of “biomedical factors.”
More recently, however, scientists have become interested in the role of nonbiological factors.
“While research has identified many risk factors for diseases and premature death,” says first and corresponding author Lewina O. Lee, Ph.D., assistant professor of psychiatry at Boston University School of Medicine, “we know relatively less about positive psychosocial factors that can promote healthy aging.”
She and her colleagues defined optimism as the “general expectation that good things will happen or the belief that the future will be favorable because one can control important outcomes.”
They suggest that because it may be possible to alter optimism using relatively straightforward therapeutic techniques, their findings have strong implications for public health.
“Our study contributes to scientific knowledge on health assets that may protect against mortality risk and promote resilient aging,” Lee adds.
What the study found
The NHS data covered 10 years of follow-up between 2004 and 2014, while the NAS data included 30 years of follow-up between 1986 and 2016.
As a routine part of both projects, all participants completed regular health surveys that included questions about diet, alcohol intake, smoking, and other health-related behaviors.
The questionnaires that they completed at the start of their respective follow-ups also included items on optimism. Although the two projects used different measures for assessing optimism, the authors note that “prior work has demonstrated [them] to be correlated.”
As an example, one of the six questions on optimism that the NHS participants completed asked them to indicate, on a five-point scale, the extent to which they agreed or disagreed with statements such as, “Overall, I expect more good things to happen to me than bad.”
Of the participants, 13% of the females died during the 10 years of their follow-up, and 71% of the males died in the 30 years of their follow-up.
When the researchers analyzed the data, they found that the females and males with the highest levels of optimism at the start of follow-up lived on average 11–15% longer than those with the lowest levels of optimism.
In addition, the females and males with the highest levels of optimism had a 50–70% greater likelihood of living until their 85th birthday and beyond.
The team found that the associations held even when they adjusted the results to account for the effects of age, educational achievement, persistent diseases, depression, physical activity, diet, use of alcohol, smoking, and visits to the doctor.
Potential reasons for the effect of optimism
Although the researchers did not investigate how optimism might help people live longer, they discuss some plausible reasons.
One potential reason is that people with higher optimism are more likely to engage in behaviors that promote health, such as not smoking and being more physically active. Both of these behaviors can lengthen lifespan.
Another factor that scientists have linked to higher optimism is the ability to regulate emotions more effectively. People who can do this recover from stressors more quickly.
“Considering psychosocial pathways, more optimistic individuals may experience less extreme emotional reactivity to, and faster recovery from, acute stressors,” write the authors.
“Together with other work,” they propose, “our findings suggest optimism serves as a psychological resource that promotes health and longevity.”
Approaches that boost psychological resources would be a departure from the mainstream methods that often seek to reduce “or repair psychological deficits.”
Some studies have shown that relatively short interventions can help people raise their level of optimism. These studies have looked at a range of interventions, including meditation, brief exercises that involve writing things down, and intensive cognitive behavioral therapy (CBT).
The authors conclude that there is a need for further research that addresses the longer term effects of such interventions.
Could the resulting improvements in optimism lead to lasting changes in health behavior?
“We hope that our findings will inspire further research on interventions to enhance positive health assets that may improve the public’s health with aging.”
Lewina O. Lee, Ph.D.