In a recent study published within the journal Scientific Reports, researchers examined the role of various adversities experienced at different life course stages on cognitive aging (i.e., level and alter).

Study: Adversity specificity and life period exposure on cognitive aging. Image Credit: myboys.me / Shutterstock

Background

Previous studies have reported on the consequences of stress during various life stages on the frontal lobes, amygdala, and hippocampus, that are involved in memory, learning, and functions related to higher cognition. Associations between socioeconomic adversity during maturity and cognition have also been documented.

Adversity impacts cognition in aging, affecting each specific and cumulative experiences. Unfortunately, existing data on adversity’s effects on cognitive performance and alter amongst older individuals is contradictory, requiring a comprehensive model to know the impact of various adversities experienced at different life course stages on cognitive function and performance.

Concerning the study

In the current study, researchers investigated the role of distinct adversities (loss of fogeys, stress, hunger, and economic hardship) experienced at three life course periods (youth, early adult age, and middle age) in predicting cognitive performance at an older age and the change in cognitive performance across the aging process (level and alter in cognition).

The Survey of Health, Ageing, and Retirement in Europe (SHARE) study data of two,662 individuals aged >60.0 years (median age of 68 years), were analyzed using structural equation modeling. The team investigated whether, at each life course period, adversity was related to lower verbal fluency (VF) performance and memory in older age and a steeper decline in VF and memory.

Only individuals having complete cognition-associated data for all follow-ups (SHARE study waves 1.0, 2.0, 4.0, 5.0, 6.0, and seven.0), who weren’t suspected of affected by dementia through the first and second waves of the study (excluding individuals with scores below 2.0 concerning temporal orientation), and people who participated who filled out the retrospective SHARELIFE questionnaire through the third or seventh wave were included in the current evaluation.

The study commenced in 2004 and was conducted every two years until 2017-2018. Cognitive improvements were observed through the first and second waves, probably due to learning effects, but showed declining trends subsequently. Due to this fact, data from only the second, fourth, fifth, sixth, and seventh waves were analyzed to evaluate changes in cognition with time.

The team assessed delayed-type recall by making the participants recall ten words that were spoken loudly through the study waves, followed by time delays during which the VF and numeracy tasks were accomplished. Participants needed to name different animals inside a minute within the VF task. Adversities were evaluated by matching various items with the adversity definitions (i.e., periods of hunger, stress, economic hardship, and the death of 1 or each parents) throughout the life course.

For every item, the participants documented the calendar 12 months of event commencement, and based on the difference within the birth dates, the team determined the period of life during which the adversity was experienced. The course of life was divided into youth (0.0 to twenty.0 years of age), early maturity (21.0 to 40.0 years of age), and middle age (41.0 to 60.0 years of age).

Results

The early experience of economic hardship predicted lower VF performance, and the experience of hunger in youth predicted lower delayed recall and lower VF performance. Nevertheless, adversities experienced later in life (in early and middle maturity) didn’t negatively predict cognition and associated changes in older age. Contrastingly, stress and economic hardship experienced in early maturity predicted delayed recall and VF performance higher in older age. In contrast, economic difficulties experienced in middle maturity predicted a lower decline in delayed recall.

Older individuals, less educated males, and people with less educated fathers had worse delayed recall performance in older age. VF performance was worse amongst elders with less educated parents and people participants who were less educated. Older individuals also declined more steeply in delayed recall performance across waves. Middle-age economic hardship reduces delayed recall, enhances cognitive performance, and encourages paid work, while maturity provides higher resources and creativity.

Conclusions

Overall, the study findings showed that adversity experienced in youth (particularly hunger and economic hardship) was negatively related to cognitive aging, which was not the case with adversity experienced later in life. The findings highlighted the importance of the sensitive period (youth) within the experience of adversity and the antagonistic effects of economic hardship and hunger early in life on later life cognitive health, which could inform social policy-making.

Adolescence adversity, hunger, and disadvantageous socioeconomic conditions could have long-lasting impacts on cognition in older age in comparison with maturity. Economic hardship experienced in youth looked as if it would influence the extent of VF performance and the change in delayed recall, probably resulting from fewer mental stimulations and a worse lifestyle resulting from economic constraints during youth, leading to a lower cognitive build-up. Hunger in youth may cause alterations in neurotransmitter systems that impact cognition.