Published in Innovation in Aging, the study analyzed information from 2,759 people in the UK who completed questionnaires across much of their lives through the MRC National Survey of Health and Development (also known as the 1946 British cohort study).

Researchers found that people who faced ongoing financial difficulties or persistently low income during early and middle adulthood tended to perform worse on cognitive tests by the age of 53.

Among a subgroup who later underwent brain scans, persistent low income was also associated with poorer brain health (including more brain shrinkage) in later life (ages 69 to 71).

These associations remained after the researchers accounted for other factors that could have influenced the results, including childhood cognitive ability, education level and childhood disadvantage.

Decades of Financial Strain May Matter Most

Corresponding author Dr. Jacques Wels (Unit for Lifelong Health & Ageing at UCL) said: "Most studies on cognitive aging 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 relationship between financial adversity and poorer brain health later in life appeared especially strong among men, people who had experienced childhood disadvantage, and those who carried APOE-ε4, a genetic variant associated with an increased risk of Alzheimer's disease.

Men who experienced persistent financial adversity also performed worse on cognitive tests at age 53 than their female counterparts.

The researchers suggested several possible explanations for this difference. Disadvantaged men may have been more likely than disadvantaged women to engage in unhealthy behaviors (such as smoking and alcohol misuse). Men in this generation may also have experienced financial strain differently because they were more likely to have been the primary breadwinners in this cohort born in 1946.

How Money Stress Could Affect the Brain

Several biological and psychological pathways could help explain the connection between financial hardship and cognitive aging.

One possibility is inflammation. Chronic stress can promote inflammation, which is known to contribute to faster brain aging.

Persistent concern about finances could also increase cognitive load. Constantly thinking about money and bills may consume mental resources, leaving less capacity available for other cognitive tasks.

The researchers also observed an unusual pattern in memory performance. Although people who experienced financial hardship or low income generally performed worse on cognitive tests at 53, their scores on a memory test declined more slowly between 53 and 69.

The researchers said this was likely because these participants had already experienced substantial cognitive losses by age 53 compared with people who had not faced persistent financial strain, leaving less room for further decline over the following years.

Tracking Income and Hardship Across Adulthood

Participants reported their household income at three stages of adulthood, at the ages of 26, 43, and 53. Researchers classified people as having persistent low income if they fell within the bottom 20% of the group at least twice. About 16% (about one in six) of participants met this definition.

Financial hardship was measured separately through questions about day-to-day financial pressure, including whether participants struggled to manage on their income or had difficulty paying bills.

People were classified as having experienced persistent hardship if their questionnaire scores crossed a designated threshold at least twice between the ages of 36 and 53. About 12% (about one in eight) of participants fell into this category.

Measuring Cognitive and Brain Health

The cognitive assessments measured verbal memory and processing speed.

Magnetic resonance imaging (MRI) scans gave researchers a way to evaluate several indicators of brain health, including brain atrophy (shrinkage) and ventricular expansion. Ventricular expansion refers to enlargement of the fluid-filled cavities within the brain and is considered a sign of poorer 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 80^th birthday earlier this year.