Does having a hobby help you live longer?

"Having a hobby can add YEARS to your life," The Daily Express reports. The headline is prompted by an international study that looked at ageing and happiness.

The study found older people who reported the greatest sense of purpose in life survived longer than those who reported having little sense of purpose, suggesting that having a meaning in life might play a role in protecting people's health.

But this study cannot prove having a hobby or other purpose in life increases the chances of surviving longer.

As the authors point out, there are many other factors involved that might have an effect on survival, including ill health and material income.

Other studies show a two-way connection between health and wellbeing. Being affected by common illnesses such as arthritis or heart disease, for example, can make it difficult to maintain a zest for life.

That said, it's obviously sensible for people to stay active as they grow older and to maintain their social activities and relationships. Having something to live for, whether it's as noble as eradicating world poverty or a little more down to earth, such as maintaining an attractive garden, could help you live longer.

Research shows people who regularly give up their time to help others, stay active, learn new things and connect with others tend to have higher reported feelings of wellbeing.

Where did the story come from?

The study was carried out by researchers from University College London, as well as Princeton University and Stony Brook University, which are both in the US.

Funding came from a variety of sources, including the US National Institute on Aging and several UK government departments.

The study was published in the peer-reviewed medical journal The Lancet.

Press coverage reported the study's findings uncritically and took some liberties in extrapolating the results. It would be simplistic to say – as the Express did – that, "having a hobby can add YEARS to your life", as many other confounding results are likely to be involved.

The Daily Telegraph's claim that, "pensioners with sense of purpose live two years longer than cynics" is overstating the study's findings. Cynicism was not even mentioned in the study.

BBC News took a slightly different take on the study, focusing on the global variations in happiness and how this changes over the course of a lifetime.

What kind of research was this?

This study is part of a Lancet series on ageing, which drew on various sources to look at the relationship between wellbeing, health and ageing.

It did not present any new evidence, but analysed findings from existing sources, such as an ongoing international poll on wellbeing and an English study of ageing.

According to the researchers, there are three different aspects to wellbeing:

evaluative wellbeing – or life satisfaction
hedonic wellbeing – feelings of happiness, sadness, anger, stress and pain
eudemonic wellbeing – sense of purpose and meaning in life

The researchers say subjective wellbeing is becoming a focus of intense debate in public policy and economics, with improvement in wellbeing a key aspiration.

Research suggests subjective wellbeing might even protect health, reduce the risk of chronic illness and promote longevity. Their paper summarises the present evidence linking subjective wellbeing with health in an ageing population.

What did the research involve?

The researchers searched online databases for relevant evidence, and included all articles published in English between January 2000 and March 2012.

For their analysis of the link between wellbeing and age in different parts of the world, they mostly drew on large-scale international surveys such as the Gallup World Poll, an ongoing survey taking place in more than 160 countries.

To look at the association between wellbeing and survival, they carried out a new analysis of an existing study, the English Longitudinal Study of Ageing (ELSA), relating eudemonic wellbeing to mortality.

In this analysis, 9,040 people with an average age of 64.9 years were followed for an average of 8.5 years, with 1,542 deaths analysed. Eudenomic wellbeing was assessed by questionnaire on issues such as sense of control, purpose in life and self-realisation. The cohort was divided into quartiles of wellbeing and were analysed for the relationship between wellbeing and survival.

What were the basic results?

The researchers' analysis of the ELSA found eudemonic wellbeing is associated with increased survival:

29.3% of people in the lowest quartile of wellbeing died during the follow-up period of 8.5 years, compared with 9.3% of those in the highest quartile
after adjustment for factors such as education, health and income, the highest quartile had a 30% lower risk of dying within the study period

They also reported on other data, which shows:

a U-shaped relation between life satisfaction (evaluative wellbeing) and age in high-income English-speaking countries, with the lowest levels of wellbeing in those aged 45-54, after which levels start to rise
this pattern is not universal – for example, respondents from the former Soviet Union, Eastern Europe and Latin America show a large progressive reduction in wellbeing with age, while wellbeing in sub-Saharan Africa shows little change with age

They also found studies that showed how the relation between physical health and subjective wellbeing is "bidirectional".

Older people with common illnesses of ageing, such as coronary heart disease, arthritis and chronic lung disease, show both increased levels of depressed mood and impaired wellbeing.

How did the researchers interpret the results?

The researchers concluded that the wellbeing of elderly people is an important objective for both economic and health policy.

"Even though the results do not unequivocally show that eudemonic wellbeing is causally linked with mortality, the findings do raise intriguing possibilities about positive wellbeing being implicated in reduced risk to health," the authors conclude.

They also concluded that the U-shaped curve in wellbeing in high-income English-speaking countries – with life satisfaction at its lowest in the 45-54 age group – is because this is the period for working and earning the most at the expense of wellbeing.

The findings about wellbeing in former Soviet Union and Eastern European countries is attributed to the recent transitions and resulting political and economic instabilities in these countries. Similar, if not as extreme, instabilities can be seen in the Caribbean and Latin America.

The flatlining of happiness in Sub-Saharan Africa, while not explicitly discussed by the researchers, is possibly a result of the high levels of poverty, and corresponding lack of opportunities to build a better life as a person grows older.

Conclusion

This is an interesting paper on the important issue of wellbeing and its potential effect on health and survival. However, as the authors point out, it does not prove that wellbeing protects health and increases the chance of living longer.

The association they found could be a result of both measured and unmeasured confounders, such as ill health. Wellbeing could be a marker for underlying biological processes that are responsible for the effect on survival.

There are likely to be bidirectional effects at work. Some people with poor health become unhappy, while others who are unhappy become physically unwell.

That said, it's sensible for people to stay active as they grow older, and maintain their social activities and relationships. Eating well, exercising regularly and maintaining a healthy lifestyle are also advised.