Scientific theories assume two mechanisms; first, that individuals with a high level of education may engage in a healthier lifestyle which protects them against dementia, and, second, that high education builds up a so called ‘cognitive reserve’, which is the ability to keep up a good cognitive performance despite brain pathology. Nonetheless, there is a lack of knowledge about how exactly education does that and how much education is possibly”enough”. Therefore, we examined in our study in more detail how education – its concepts and its operationalisation – impacts the risk of developing dementia.
In our study, the Leipzig Longitudinal Study of the Aged (LEILA75+), individuals aged 75 years and older were recruited from the population registry office in the city of Leipzig, Germany. A total of 1,692 community-dwelling individuals (with 11.3% living in retirement homes) were identified.
Trained psychologists and physicians visited the participants in their home environment and conducted a standardized interview including a cognitive assessment for dementia diagnosis. These interviews were repeated in up to five follow-up assessments at an interval of 1.5 years and a final assessment after 15 years.
Examining the data obtained, we observed that every additional year of education significantly decreased the risk of developing dementia, even after taking into consideration age, gender, living situation, having had a stroke, heart attack diabetes, or depression. In particular, ‘having completed more than ten years of education’ or a ‘tertiary level of education’ appeared to be an important threshold for significantly reducing dementia risk. Complex classifications of education, which focused on occupational expertise and hierarchy of levels, did not seem to be relevant concerning dementia risk.
Our findings thus suggest that predominantly education expressed in the number of years has a protective effect against dementia, with an important threshold for completing more than ten years of education or a tertiary level. One way to interpret our findings is that factors like learning objectives or qualifications do not necessarily explain the effect that education has on dementia risk. It seems to be rather the duration of mental training – i.e. years of education – that is the factor lowering dementia risk. Further investigations should explore the details of the pathways from education to dementia risk. Moreover, further research should evaluate what level of education would be optimal as a major public health goal, especially for developing countries, in order to reduce the effect of dementia on health care systems and society.
Our observations also emphasize the importance of considering definitions and operationalisation in dementia research. Only by being aware of these will it be possible to gain a better understanding of the processes which influence dementia risk.
Francisca S. Then is researcher at the Institute of Social Medicine, Occupational Health and Public Health (ISAP) and the LIFE – Leipzig Research Center for Civilization Diseases at the University of Leipzig, Germany, with a major research focus on the epidemiology of cognitive decline and dementia. She discussed her recent Age & Ageing paper ‘Education as protector against dementia, but what exactly do we mean by education?‘
View the Age & Ageing paper ‘Education as protector against dementia, but what exactly do we mean by education?‘