For many, dementia is a kind of spectre that hides behind ageing. For a long time it was thought that one could protect oneself from dementia later on by being mentally active. A new study, however, is now severely undermining this thesis. We have investigated what exactly is behind this study and how its results are to be interpreted.
Doesn’t mental activity protect against dementia later on after all?
The study structure
This British study with 850,000 participants dealt with exactly this question. The women, who were on average 60 years old, were asked about their leisure activities. Adult education courses, arts, crafts, music or even daily reading – everything was included in the evaluation. At the same time, the Oxford University researchers recorded all diagnoses of dementia among the participants over the following 16 years. Based on this, they calculated a relative risk of the disease for the first 4, 9 and over 10 years.
During the study period, 4% of the participants developed dementia. Of these, however, only 3% developed dementia in the first four years. Another 15% were diagnosed after 5-9 years, and a full 82% developed dementia only after more than 10 years. The average age at diagnosis was 79 years.
In fact, it showed that the participants who regularly engaged in mental activities had a significantly lower risk of developing dementia. Unfortunately, this only applies to the first 4 years after the start of the study. In the period of 5-9 years, the positive effect decreased noticeably and became completely negligible after more than 10 years. This means that a positive effect in the prevention of dementia was only detectable in the first 4 years of the study.
The conclusion of the study management
The editors of the study write “that there is a progressive reduction in participation in mental activities” years before a dementia diagnosis. “However, the activities themselves have little or no relevance to the onset of dementia.”
In other words, “mental activities are not a protective factor against the development of dementia.”
Those responsible are therefore calling for the official guidelines on dementia to be reformulated. Until now, the international consensus has been that mental activity has a protective effect on the onset of dementia.
Criticism of the study
Experts warn against taking the new study as the measure of all things and point to some clear weaknesses in the collection of data:
- The type of intellectual activities was recorded in a far too undifferentiated manner. It was only recorded whether the participants read regularly. A precise recording of how much and, above all, what exactly was read did not take place. Of course there is a clear difference between whether someone reads only a few pages of a dime novel every day or whether they occupy themselves with more sophisticated, possibly even specialised literature.
- Furthermore, the diagnosis of dementia is still problematic. In many countries dementia is severely underdiagnosed. Relating the study results only to the clinical diagnosis of this complex neurological disease is not reliable enough.
- A whole series of other studies would clearly contradict the claims of the Oxford researchers. And we also think: A single study, no matter how sensational, should never outweigh all the contrary findings.
Conclusion
Of course, it is always difficult or impossible to single out a single factor when it comes to complex interrelationships. Dementia is certainly no exception. Often the lack of communal activities leads to social isolation and frequently also to less physical activity. This creates a vicious circle in which the decisive moment finally becomes blurred and can no longer be identified.
So as long as the Oxford study is not supported by other, independent research findings, there can be no question of condemning the previous recommendations. After all, a positive effect of mental activity could be recorded at least in the first four years. Even a slowing down of the disease is progress that should be maintained.
If you are thinking about this topic, don’t let it stop you from being intellectually active. Engage in content that interests you, that challenges you mentally and that you can enjoy! Mental activity may well provide some protection against dementia. We will gladly stay tuned to this topic for you.
If you would like to have a look at the study yourself, please click on the following link:
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(20)30284-X/fulltext#%20