Persistent financial hardship accelerates age-related cognitive decline, according to a new study led by University College London (UCL) researchers.

The study, published in Innovation in Aging, looked at data from 2,759 people in the UK who filled in questionnaires throughout their lives as part of the MRC National Survey of Health and Development (also known as the 1946 British cohort study).

The research team found that people who experienced either persistent money struggles or persistent low income in early and middle adulthood performed less well in cognitive tests by the age of 53.

Looking at a subgroup of people who had brain scans, the team found that those who experienced persistent low income had worse brain health (including more brain shrinkage) in later life (ages 69 to 71).

These links remained even after accounting for factors that might have skewed the results such as childhood cognition, education level and childhood disadvantage.

Corresponding author Dr Jacques Wels (Unit for Lifelong Health & Ageing at UCL) said: "Most studies on cognitive ageing look at financial hardship at only a single point in time. Our study using several decades of data allows us to see that it is the accumulation of hardship over many years that is linked to the worst cognitive health outcomes, rather than occasional episodes of adversity."

Senior author Professor Praveetha Patalay (Unit for Lifelong Health & Ageing and Centre for Longitudinal Studies, UCL) said: "Our findings suggest that supporting people facing financial hardship and reducing chronic poverty could also help prevent cognitive decline and dementia cases in the future."

The research team found that the link between financial adversity and poorer brain health in later life was particularly strong for men, those who experienced childhood disadvantage, and those who carried a genetic variant, APOE-ε4, that raises Alzheimer's risk.

Men who experienced persistent financial adversity also did less well in cognitive tests at aged 53 than female counterparts. Possible reasons for this difference might include that disadvantaged men may have worse health behaviours (such as smoking and alcohol misuse) than disadvantaged women and that men might experience the stress of financial adversity more, especially as they would have been the primary breadwinners in this cohort born in 1946. 

The researchers mention different mechanisms that could link cognitive ageing and financial hardship including inflammation, which is known to accelerate brain ageing and which is caused by chronic stress.

Another factor is that frequently worrying about money may increase cognitive load, leaving people with less bandwidth for other cognitive tasks.

The researchers also said that, while those who experienced financial hardship or low income did less well on cognitive tests at 53, their performance in a memory test declined more slowly between 53 and 69, which was likely due to them already having suffered significant cognitive losses compared to counterparts who did not have persistent financial strain.

Study participants were asked about their household income at three points, at the ages of 26, 43 and 53, and classed as having persistent low income if they were in the bottom 20% of the group at least twice, which amounted to 16% (about one in six) of the participants.

Financial hardship was assessed using questions such as whether people found it hard to manage on their income and whether they had had trouble paying for bills. Participants were classed as having experienced persistent hardship if they scored above a threshold on the questionnaire at least twice between the ages of 36 and 53. This represented 12% (about one in eight) of the participants.

Cognitive tests assessed verbal memory and processing speed; magnetic resonance imaging (MRI) scans allowed researchers to measure factors such as brain atrophy (shrinkage) and ventricular expansion – i.e., the expansion of fluid-filled cavities in the brain – which is a sign of poor brain health.

The 1946 British cohort study, hosted by UCL, is the world's longest continuously running birth cohort study. Participants (who were enrolled at birth) celebrated their 80th birthday earlier this year.

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