Why do some people develop dementia while others maintain good cognitive health into old age? And what factors shape how our thinking abilities change throughout life? Data from the Longitudinal Aging Study Amsterdam (LASA) help answer these questions.
LASA is a large-scale, long-running study of older adults in the Netherlands. Since 1992, approximately 5,000 adults aged 55 and older have been followed over time. By collecting information on health, cognition, lifestyle, and social factors across many years, researchers gain valuable insight into how cognitive functioning changes with age—and why these changes differ from person to person.
Understanding cognitive ageing
As populations age, the number of people living with dementia and cognitive decline continues to rise. Understanding the factors that contribute to cognitive decline is therefore increasingly important. Greater knowledge of these factors can help researchers identify cognitive decline earlier and improve our understanding of the underlying processes.
We often think of aging as a process of decline, but LASA shows that people follow very different aging trajectories.
Which factors influence cognitive decline?
One of the key findings from LASA is that cognitive aging does not occur at the same rate—or in the same way—for everyone. Although cognitive abilities generally decline with age, the pace of decline varies considerably between individuals.
For example, a study using LASA data found that, in midlife women tend to perform better than men on memory tasks and processing speed—the ability to absorb, understand, and respond to information quickly. However, this advantage decreases later in life because women experience a faster rate of cognitive decline. These difference between men and women may partly be explained by the fact that women have fewer cardiovascular risk factors..
Other LASA studies have identified several factors associated with dementia and cognitive decline. Diabetes and depressive symptoms were found to be important predictors of accelerated decline in processing speed. Sleep problems were associated with declines in multiple domains of cognitive functioning years later and were also linked to an increased risk of dementia.
Researchers also found that personality changes, such as increasing neuroticism, were more common among individuals who later developed dementia. Neuroticism refers to a tendency to experience negative emotions more frequently and intensely and to have greater difficulty coping with stress.
At the same time, LASA studies have identified factors that may help support cognitive health. The findings highlight the importance of maintaining good cardiovascular health. Researchers also found indications that playing a musical instrument and using the internet are associated with better preservation of cognitive functioning. These observations provide interesting directions for future research to determine whether these relationships are causal.
Dementia does not begin at a single point in time. Many risk factors accumulate and interact throughout life. That is why it is important to take a life-course perspective.
Bob van de Loo, Postdoctoral researcher, LASA, Amsterdam UMC
Understanding cognitive health across the life course
“Risk factors for dementia and cognitive decline are diverse and touch on many aspects of aging,” says Van de Loo. “One of LASA’s strengths is that we study cognitive health in relation to physical health, lifestyle, and social factors. This broader perspective helps us better understand why cognitive decline and dementia develop differently across individuals.” At the same time, he emphasizes that LASA represents only part of the larger picture. Van de Loo: “LASA provides an important piece of the puzzle by focusing on later life, but to fully understand dementia we need to examine the entire life course.”
Evidence from other studies increasingly suggests that risk factors begin to play a role much earlier in life, including during childhood, adolescence, and midlife. By combining data from multiple cohorts, researchers can gain a more complete understanding of how risk factors at different stages of life interact and contribute both directly and indirectly to the development of dementia and cognitive decline later in life. This knowledge may ultimately help prevent cognitive decline and dementia before symptoms emerge.
About the LASA research team
LASA is supported by a dedicated core team of staff members, together with researchers, PhD candidates, and interviewers. The study is a collaboration between the Vrije Universiteit Amsterdam and Amsterdam UMC, location VUmc, bringing together expertise from a wide range of disciplines, including epidemiology, sociology, nutrition science, internal medicine, and psychiatry.
Learn more
To make findings from LASA research accessible to a broader audience, the research team developed a fact sheet and infographic on cognition and dementia.
View the fact sheet: Factsheet Cognitie en Dementie (in Dutch)
View the infographic: Infographic Cognitie en Dementie (in Dutch)
The fact sheet and infographic were made possible in part through support from Stichting Hofje Codde en Van Beresteyn.