Higher levels of wellbeing may help reduce the risk of memory loss in middle age, suggests new research, which tracked more than 10,000 over 50-year-olds across a 16-year span.
Findings that are published today, in the peer-reviewed journal Aging & Mental Health , found those who said they had higher wellbeing were more likely to subsequently have better scores on memory tests.
These people – all of whom were determined as having 'healthy brains' – also reported a greater sense of control, independence, and freedom to make choices.
This association between psychological wellbeing and better recall was small but significant. The link was also independent of depressive symptoms, according to the researchers.
However, the analysis by a cohort of 15 experts across the UK, US and Spain found no evidence to suggest better memory was linked with later higher wellbeing, although the authors say the possibility cannot be discounted.
The academics add that the results highlight that psychological and social factors affect brain health, and wellbeing may protect against cognitive impairment. Interventions to promote psychological wellbeing such as mindfulness could maintain mental functions such as memory as people age.
"In the context of an ageing population, understanding factors that may protect and maintain healthy cognitive function is critical for enhanced population health and health policy development," explains lead author Dr Amber John, a Lecturer in Psychology at the University of Liverpool and a current Alzheimer's Research UK Fellow, who specialises in research on ageing, with a specific focus on mental health, neurodivergence, and dementia.
"While, in this research, we can't examine and understand the relationship between causes and effects, determining if one event leads to another (causality), our findings are important in proposing that good wellbeing predates better memory rather than vice versa. This suggests that the link between wellbeing and memory is not just because people with poor memory have poor wellbeing and that, if causality is demonstrated, improving wellbeing could protect against subsequent memory decline."
Co-author Joshua Stott, a Professor of Ageing and Clinical Psychology at UCL, adds: "This study represents an important step toward understanding the interplay between wellbeing and memory over time. It offers new insights into how self-rated wellbeing is associated with memory and vice versa.
"While our findings are preliminary, they highlight the importance of considering psychosocial influences on brain health such as memory."
Depression and anxiety are widely recognised as risk factors in faster decline of brain health and dementia. A key global healthcare priority is now to prevent dementia.
Wellbeing is defined as emotional health combined with being able to function effectively. Happiness, confidence, a sense of purpose and control over life are among the elements of wellbeing.
Existing studies have suggested a positive link between wellbeing, age-related decline in mental processes in the brain, and mild impairment of these functions. Memory is regarded as a cornerstone of an individual's mental processes.
However, most studies have only tested this link between wellbeing and memory in one direction or another. The aim of this research was to provide longer-term insights into the relationship between wellbeing and memory in people who have yet to experience significant cognitive decline.
Data was based on 10,760 men and women who took part in the English Longitudinal Study of Ageing Self-reported. This existing long-term research project involves UK adults over the age of 50 and includes attitudes to well-being.
Participants were assessed on wellbeing and memory every two years – a total of nine times during the 16-year study period stretching back to 2002.
Researchers used a learning task to check participants' ability to recall ten words immediately and after a delay. Wellbeing was assessed using a quality-of-life questionnaire. Participants scored themselves based on satisfaction of specific needs – pleasure, control, autonomy, and self-realisation. Questions included 'I can do the things that I want to do', and 'I feel that life is full of opportunities'.
The authors excluded anyone with a dementia diagnosis at the start of the study.
Results showed a small but significant association between higher wellbeing and better memory. In addition, the study found that the impact of wellbeing on memory was significant even after adjusting for depression. The authors say this suggests links between wellbeing and memory exist independent from depressive symptoms.
Biological factors such as cardiovascular disease and those linked to lifestyle – such as physical activities – are among possible reasons for the effect of wellbeing on memory, say the authors. Age, gender, lifestyle, and socioeconomic status may also have a negative or positive impact on the relationship between wellbeing and memory function.
Despite the lack of evidence for memory affecting wellbeing, the authors say this cannot be ruled out. They say lower psychological wellbeing may be a sign of 'oncoming cognitive impairment' before symptoms become apparent.
The research was funded by Alzheimer's Research UK; Medical Research Council (a part of UKRI); National Institute on Aging; and National Institute for Health and Care Research (NIHR).
Emma Taylor, Information Services Manager at Alzheimer's Research UK, comments: "Loving your heart, staying sharp and keeping connected are key to protecting our brain health as we age.
"There are 14 established health and lifestyle risk factors for dementia, including lack of physical exercise, social isolation, and depression, which are linked to wellbeing.
"This study found that people over 50 who reported they felt happier and more fulfilled in life had a better memory over time. However, this research is observational – and more work is needed to understand how a positive wellbeing and memory are connected and whether this has a knock-on effect on dementia risk.
"Looking after our mental wellbeing plays an important part in our overall health. And it's never too late to start taking steps to keep our brains healthy throughout our lives and lessen the devastating impact of dementia."
As with all long running longitudinal studies, one limitation of this paper is sample attrition over the follow-up period. However, the team used a research methodology which enabled use of use of all available information in the observed data, without imputation or discarding cases.
To conclude, authors say their results could provide the basis for further research into what factors can enhance brain health in aging populations.
Co-author Dr Emily Willroth, an Assistant Professor of Psychological & Brain Sciences at Washington University, in St Louis, Missouri, adds: "Going forwards it would be fantastic if this research can build on the foundations of ongoing memory research to potentially inform strategies supporting cognitive health in ageing populations – that is the aim."
