Brain blog showcase: Do we really lose it if we don’t use it?

All this week we’ve been showcasing the work of students who have been “researching the headlines” as part of their undergraduate studies. Their task was to describe an original research report exploring how lifestyle affects brain health in a manner accessible to non-experts, as well as evaluating the media coverage of the research. If you’re interested in using this approach in your own teaching, you can contact Alan Gow (A.J.Gow@hw.ac.uk) for more information and materials.

For our final “brain blog”, we have…

Do we really lose it if we don’t use it?

by Chloe Meek

Most of us look forward to the day that we can sit back, put our feet up and enjoy retirement. And quite rightly so, as the majority of our adult life is spent at work.  However, the Telegraph recently reported that retirement may not be the best option if we want to stave off cognitive ageing.

The research reported in the Telegraph was carried out by researchers at University College London, King’s College London and Queen Mary University. They were interested in the relationship between retirement and cognitive function. Specifically, they wanted to find out if retirement influenced the decline of: verbal memory (memory for words), abstract reasoning (ability to detect patterns and think quickly) and verbal fluency (ability to retrieve specific words in the task). The ‘use it or lose it’ hypothesis suggests that a lack of mentally stimulating activities may speed up cognitive decline.

The study, published in the European Journal of Epidemiology, used data from the Whitehall II study. This is an ongoing prospective study exploring wellbeing and health in an ageing population. It recruited civil servants (aged 35-55) with a range of job roles. The current study used data from 3,433 individuals who participated in the Whitehall II study between 1997 and 2013, when information on cognitive function had been collected. All participants were retired and had participated in at least one cognitive assessment.

Four waves of cognitive assessment were used to compare cognitive function up to 14 years before and after retirement. While verbal memory declined 38% faster after retirement, there was no major impact on any other cognitive domains. Additionally, they found that a higher employment grade was protective against verbal memory decline. However, this ‘protective effect’ wore off after retirement, resulting in a similar rate of decline across all job roles. This suggests that particularly mentally stimulating employment can protect against cognitive decline, to an extent.

The study has some strengths in that it was able to analyse a large number of people and look at cognitive change over a prolonged period of time, both before and after retirement. It also took into account a number of important factors that may contribute to a decline in cognition (such as smoking status and blood pressure). However, the association found in the study may have arose from other, unaccounted contributing factors. Large, prospective studies such as the Whitehall II provide access to a large body of data. However, it may not have collected all of the relevant information to properly examine the influence of retirement on cognitive function as this was not what it was set out to do.

Furthermore, the study had half the number of women to men. This may have influenced the results as men and women often have different retirement patterns and experiences. Compared with the general population, those recruited in the Whitehall II study may have had more mentally challenging job roles, meaning their outcomes are not representative of the general population.

It is difficult to conclude that retirement was the only influence on the cognitive outcomes. As a correlational study, no cause and effect can be attributed. For example, the loss of social interaction at work may have played a role. The study did not assess the effect of post-retirement activities such as volunteering, socialising and physical pursuits that may reduce the likelihood of cognitive decline.

The Telegraph was one of many news outlets to cover this research. They managed to report the results and methods clearly while mentioning where the study was published and provided a link to it. However, they did exaggerate the implications of the results. For instance, they began their report with, “Retirement causes brain function to rapidly decline”. This is not true as only verbal memory was found to decline faster after retirement, while other important cognitive functions remained unaffected. Verbal memory may be essential in the workplace and therefore enhanced during working years. So, the decline during retirement is not unexpected and may not affect individuals in their daily lives.

Additionally, the media article uses the study to claim retirement as a catalyst for dementia, by using a quote from Cary Cooper, who had no apparent link to the research. This is wrong as the study makes no suggestion of this and it may lead to increased anxiety for those nearing retirement. This could be seen as irresponsible reporting.

The bottom line is that regardless of employment, cognitive function will decline with age. While we are likely to experience cognitive decline in retirement, this decline may not be drastic and most likely will not affect our everyday lives significantly. Employment therefore is not the only way to deter cognitive decline. Staying as physically and mentally active as we can, with a strong social network throughout retirement should help maintain our cognitive function.

Sarah Knapton. (2018). Retirement causes brain function to rapidly decline, warn scientists. The Telegraph. Retrieved 5 February 2018, from http://www.telegraph.co.uk/science/2018/01/22/retirement-causes-brain-function-rapidly-decline-warn-scientists/

Xue, B., Cadar, D., Fleischmann, M., Stansfeld, S., Carr, E., & Kivimäki, M. et al. (2017). Effect of retirement on cognitive function: the Whitehall II cohort study. European Journal Of Epidemiology, 1-13. http://dx.doi.org/10.1007/s10654-017-0347-7