Subjective wellbeing which refers to feelings of enjoyment and satisfaction with life was associated with greater longevity in previous studies. But they measured wellbeing on a single occasion, and the importance of sustained wellbeing is not known.
‘People with fewer reports of enjoyment had a higher mortality risk. Wealth, employment, education and mostly women were more likely to have reduced risk of mortality.’
Researchers at University College London decided to test whether repeated reports of enjoyment of life over a period of several years would have a stronger association with mortality than a single occurrence.
The study involved 9,365 men and women aged 50 and older (average age 63) who were taking part in the English Longitudinal Study of Ageing (ELSA). Measures of enjoyment of life were assessed three times at two-year intervals between 2002 and 2006 and associations with mortality were analysed up to 2013.
Participants who responded 'never or rarely' to each of four questions about enjoyment were classified as having no enjoyment, while those responding'sometimes or often' were categorised as having high enjoyment. A range of factors that could influence the results were also taken into account, such as wealth, education, underlying health issues, and depressed mood.
Nearly 24% of participants reported no high levels of enjoyment of life on any occasion, with 20% having one, 22% having two, and 34% having three reports of high enjoyment.
The number of reports of high enjoyment of life was greater in women, and in participants who were married or cohabiting, well educated, wealthier, younger, and currently employed.
During the follow-up period there were 1,310 deaths. A graded effect was seen, with progressively higher mortality among people with fewer reports of high enjoyment.
For example, compared with the no high enjoyment group, all-cause mortality risk was reduced by 17% among people giving two, and by 24% in those giving three reports of high enjoyment of life.
The authors point out that this association may be biased by reverse causality, where serious illness leads to a lack of enjoyment and also increases risk of dying.
In a bid to correct for this, they carried out a further analysis restricted to deaths at least two years after the last measurement point. But this made no difference to the findings.
This is an observational study, so causal conclusions cannot be drawn, they stress. Nonetheless, they say these results "add a new dimension to understanding the significance of subjective wellbeing for physical health outcomes by documenting a dose-response association with sustained wellbeing."
- Paola Zaninotto et al., Sustained enjoyment of life and mortality at older ages: analysis of the English Longitudinal Study of Ageing, BMJ(2016),