Steptoe A, Wardle J. Enjoying Life and Living Longer. Arch Intern Med. 2012;172(3):273-275. doi:10.1001/archinternmed.2011.1028
Department of Epidemiology and Public Health, University College London, London, England
There is accumulating evidence that positive well-being is associated with reduced mortality and risk of coronary heart disease (CHD) and other diseases of older age.1- 3 To our knowledge, this association has not previously been investigated in a nationally representative sample in which extensive health and behavioral data are available. We therefore used the English Longitudinal Study of Aging (ELSA) to evaluate prospective associations between enjoyment of life and survival.
The ELSA began in 2002 with 11 391 men and women 50 years and older living in England.4 Comparisons of the sociodemographic characteristics of participants against results from the national census show that the sample is representative of the English population. Of the core sample, 94.8% consented to data linkage to mortality records. Participants were tracked for a mean of 7 years, 3 months. Complete data on well-being, health behavior, and survival were available from 1251 fatalities and 7774 survivors.
Enjoyment of life was assessed with the pleasure subscale from the CASP-19 (Control, Autonomy, Self-realisation and Pleasure)5 and depression with the Center for Epidemiologic Studies Depression (CES-D) Scale. Socioeconomic status was indexed by total household wealth. Education, marital status, employment, smoking, physical activity, and alcohol consumption were also recorded. Participants were asked if they experienced limiting long-standing illnesses and whether they had been diagnosed as having clinical depression, CHD, cancer, diabetes, stroke, heart failure, and chronic lung disease.
The sample was divided by into quartiles of enjoyment of life. Cox proportional hazards regression models were used, testing models that successively adjusted for age and sex, demographic factors, health indicators, depression, and health behaviors. Similar results were obtained when enjoyment was modeled as a continuous variable.
Participants in the higher enjoyment group were, on average, younger and more likely to be female, married, better educated, and wealthier than those with lower enjoyment scores (eTable 1). They had lower depression scores and fewer illnesses, were less likely to be smokers, and were more likely to be physically active. The proportion of people who died over the follow-up period was 20.4% in the lowest enjoyment quartile, 15.7% in the second, 11.6% in the third, and 6.4% in the highest enjoyment quartile. Compared with the lowest enjoyment group, the age- and sex-adjusted hazard ratio was reduced for all other quartiles in a dose-dependent fashion, so participants in the highest enjoyment quartile had a 57.5% reduced risk of death (Table). This was attenuated when demographic factors, baseline health, depression, and health behaviors were taken into account, but in the full model, the highest enjoyment group still showed a hazard ratio of 0.717. Other factors independently associated with mortality are detailed in eTable 2.
As a guard against pre-existing illness leading both to diminished enjoyment of life and premature mortality, an additional analysis was conducted excluding individuals who died within 2 years of the baseline assessments. In this subgroup, death rates were 16.4%, 13.2%, 9.7%, and 5.4% in the lowest to highest enjoyment quartiles, and the proportional hazards regression models were similar to those for the full sample (eTable 3).
Subjective well-being is a central societal aspiration. This study indicates that one aspect of well-being—enjoyment of life—is associated with longer survival in a dose-dependent fashion. One danger in the investigation of positive well-being is that findings simply reflect the adverse effects of depression and other negative states.6 However, a substantial protective effect of enjoyment remained after controlling for depression, suggesting that positive affect has independent associations with health outcomes.
Greater enjoyment of life was associated with less prevalent illness, greater wealth and education, being married, and being in paid employment, all of which have established links with survival. These factors accounted for approximately one-third of the protective effect of enjoyment in the present analyses. But greater enjoyment was associated with a 28% lower risk of death even after these factors, as well as depression and health behaviors, had been taken into account.
Other factors may be responsible for the remaining association between enjoyment and survival. It may be caused by unmeasured confounding factors such as other pre-existing illnesses. Only 3 health behaviors were assessed, and other aspects such as diet may be relevant. In addition, direct links with health outcomes are plausible, since biological responses such as reduced cortisol output in everyday life and attenuated cardiovascular and inflammatory responses to stress are related to positive well-being.7
The results of this study do not establish that enjoyment of life is causally related to survival. Enjoyment may be a marker of underlying health-related biological, behavioral, or dispositional factors that are responsible for the association. Nonetheless, our findings show that the link between enjoyment and survival at older ages is not fully accounted for by demographic factors or major pre-existing illnesses. These results highlight the importance of positive well-being in older adults and suggest that efforts to improve enjoyment of life, as well to manage and prevent disease, could have beneficial effects on life expectancy.
Correspondence: Dr Steptoe, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Pl, London WC1E 6BT, England (email@example.com).
Author Contributions: Dr Steptoe had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Steptoe and Wardle. Acquisition of data: Steptoe. Analysis and interpretation of data: Steptoe and Wardle. Drafting of the manuscript: Steptoe and Wardle. Critical revision of the manuscript for important intellectual content: Steptoe and Wardle. Statistical analysis: Steptoe and Wardle. Obtained funding: Steptoe. Administrative, technical, and material support: Wardle.
Financial Disclosure: None reported.
Funding/Support: The English Longitudinal Study of Ageing was developed by a team of researchers based at University College London, the Institute of Fiscal Studies and the National Centre for Social Research. The funding is provided by the National Institute on Aging (grants 2RO1AG7644-01A1 and 2RO1AG017644) and a consortium of UK government departments coordinated by the Office for National Statistics. The data are lodged with the UK Data Archive. Dr Steptoe is funded by the British Heart Foundation, and Dr Wardle by Cancer Research UK.
Disclaimer: The views expressed in this article are those of the authors and not necessarily of the funding bodies.