Health and wellbeing benefits equal to those of regular exercise, findings suggest.
Membership of social groups, such as book clubs or church groups, after retirement is linked to a longer life, with the impact on health and wellbeing similar to that of regular exercise, suggests research published in the online journal BMJ Open.
The more groups an individual belongs to in the first few years after s/he stops working, the lower their risk of death, the findings show.
Retirement represents a major life change, with the evidence from large long-term studies suggesting that the health and wellbeing of a substantial number of retirees goes downhill after they stop formal work.
But some people adjust to this transition better than others. In a bid to assess the potential impact of social group memberships, the researchers tracked the health of 424 people for six years after they had retired.
They were compared with the same number of people, matched for age, sex, and health status, but who were still working.
All the participants were at least 50 years old, living in England, and taking part in the English Longitudinal Study of Ageing, which started in 2002-3.
Each participant was asked how many different organisations, clubs, or societies, s/he belonged to, and which ones. They were also asked to complete a validated scale to assess quality of life, and another, to assess subjective physical health.
The results showed that individuals whose quality of life was good before retirement were more likely to score highly on quality of life assessment after retirement.
But membership of social groups was also associated with quality of life. Compared with those still working, every group membership lost after retirement was associated with around a 10% drop in quality of life score six years later.
Some 28 (6.65%) of the retirees died in the first six years after stopping work. Unsurprisingly, the strongest predictor of death was age, with someone at the age of 55 running a 1% risk of dying compared with an 8% chance for someone aged 65.
Subjectively rated health was not a significant predictor of death, but the number of group memberships was.
If a person belonged to two groups before retirement, and kept these up over the following six years, their risk of death was 2%, rising to 5% if they gave up membership of one, and to 12% if they gave up membership of both.
No such patterns were seen for those still in formal employment.
The researchers separately assessed whether changes in physical activity levels affected risk of death and compared this with the magnitude of the effect of social group membership.
They found that if a person exercised vigorously once a week before retirement, and kept up this frequency afterwards, their chance of dying over the next six years was 3%, rising to 6% if they reduced the frequency to less than once a week, and to 11% if they stopped altogether.
Among those who were still working, the equivalent figures were 3%, 5%, and 8%.
"Accordingly, we can see that the effects of physical activity on health were comparable to those associated with maintaining old group memberships and developing new ones," write the researchers.
This is an observational study so no firm conclusions can be drawn about cause and effect, but the findings have unique practical implications for retirement planning, say the researchers.
"They suggest that as much as practitioners may help retirees adjust by providing support with financial planning, they may also help by providing social planning," they write.
"In this regard, practical interventions should focus on helping retirees to maintain their sense of purpose and belonging by assisting them to connect to groups and communities that are meaningful to them," they conclude.