Martin Seligman is the originator of an increasingly mainstream theory of health and behavior known as Positive Health. His theory suggests that we should cultivate and maintain ‘positive health assets’ – things like optimism, connectedness, a stable marriage and so forth – because they contribute to a healthier, more fulfilling life and improved life expectancy as well.
In earlier posts on the matter, I reviewed 2 studies that support Seligman’s theory. In the first, Harvard scientists showed that emotional and cognitive well-being was associated with a reduced rate of coronary events. In the second, University of Michigan scientists showed that optimism was an independent predictor of short term stroke risk.
Recently, scientists at the Karolinska Institutet undertook to study this aspect of Positive Health. Once again, the findings support Seligman’s concept.
As was the case for the first 2 studies, support for the new study was provided by the Robert Wood Johnson’s Pioneer Portfolio.
In the new study, Francisco Ortega and colleagues set-out to study the association between psychological well-being and cardiorespiratory fitness, and their combined effects on survival.
The scientists used data from the Aerobics Center Longitudinal Study (ACLS), a prospective epidemiologic investigation of more than 5,000 volunteers that began in 1988. At the time of enrollment, participants had a thorough clinical evaluation including a history, physical exam, blood chemistry tests and an exercise test. Participants ranged in age from 20-81. They were followed annually until they died or the study ended, in 2003.
In ACLS, psychological well-being was evaluated at the time of enrollment using negative and positive emotion subscales from the Center for Epidemiologic Studies depression (CES-D) test. Questions in this test asked about how frequently respondents experienced certain feelings in the preceding week. The negative emotion subscale included things like ‘my life had been a failure’, ‘not able to shake off the blues’, and ‘depressed’. The positive emotion subscale included things like ‘feeling as good as other people’, ‘happy’ and ‘hopeful’.
What Did They Find?
After adjusting for traditional cardiovascular risk factors, the scientists found that participants with low levels of negative emotion had a 34% lower risk of death than peers reporting high levels of negative emotion. The protective effect was localized to those with high levels of cardiorespiratory fitness (CRF): high levels of CRF were themselves associated with a 46% reduction in mortality risk, but in the subset of participants that had both high levels of CRF and low levels of negative emotion, there was a 63% lower mortality risk. (more…)