Are there ways to prevent dementia

Prevention against dementia - more than a pious wish?

When the average life expectancy is reached, one in three people in Germany will develop dementia, mostly Alzheimer's. The question is therefore rightly asked whether there are any preventive measures. Targeted prevention through certain drugs is not yet possible today. The causes are still not known precisely enough for this. However, this does not rule out the possibility of unspecific prevention. Their goals are to increase the brain's resistance to the disease process, to eliminate factors that favor the disease, and to avoid damage to the brain from secondary diseases.

Ideally, preventive measures of this kind should relate to behaviors and lifestyles that can be changed early and on a sustained basis. This article summarizes the current state of knowledge about the prevention of dementia.

Physical activity

One of the possible protective factors is physical activity. Several studies have shown that extensive exercise in the elderly is associated with up to a 50% reduction in the incidence of mental impairment. Physical fitness naturally also promotes the quality of life and contributes to a balanced mood.

Mental agility

Another habit that is important from a preventive point of view is mental activity. A study of 800 members of religious orders showed that regular participation in mentally stimulating activities was associated with a reduced incidence of dementia after an observation period of five years.

In a further study of almost 500 people over the age of 75, the frequency of memory disorders after six years was all the less the more intensive activities such as reading, writing, crossword puzzles, card or board games, group discussions or making music were carried out. In this context, the experience is interesting that passive leisure activities such as watching television are associated with an increased likelihood of memory impairment - in contrast to active activities such as reading or board games. It cannot be ruled out that the effect of mental agility is related to the individual level of training. More educated people are more likely than less educated people to engage in mentally stimulating activities.

nutrition

The diet could also have preventive effects. Several studies have suggested that an abundant diet of vitamins C and E could be linked to a reduced risk of disease. A dietary supplement with vitamin E is not advisable because of the associated increased mortality. Participants in a French study who ate fish at least once a week suffered less dementia than participants who never ate fish after an observation period of seven years. In another study, weekly consumption of fish was linked to slower progression of memory problems. It is believed that the possibly protective effect of fish can be explained by the content of omega-3 fatty acids. The ratio of polyunsaturated to saturated fatty acids in food may also have a preventive effect.

Treating high blood pressure

An important finding for the prevention of dementia concerns the role of circulatory disorders in the brain. They are very common in the elderly, including those with Alzheimer's disease. If, in addition to the fine-tissue changes in Alzheimer's disease, there are circulatory disorders at the same time, dementia will develop more quickly. This fits in with the results of a European study, according to which the systematic treatment of high blood pressure, which is the most important risk factor for circulatory disorders, reduces the incidence of newly diagnosed dementias by half.

Assessment of the preliminary findings

The knowledge available so far about the possibilities for preventing dementia comes from retrospective studies. Typically, two groups of people were compared, one with the suspected protective factor and the other not. Because the assignment to the two groups is not random, there may be an uneven distribution with regard to other influencing variables that are related to the risk of dementia. For example, participants in the study mentioned above who consumed more fish were also better educated. So you don't know whether the better education or the food components contained in the fish are responsible for the lower risk of dementia.

In order to prove beyond any doubt that a potentially protective factor actually has a preventive effect, two groups of participants must be compared with each other in a long-term study, of which, according to a random process, one has the protective factor, the other does not, but otherwise not differ from each other. The target variables are the number of new cases of dementia and the time of their occurrence.

The only protective factor that has so far been proven in such a study is the treatment of high blood pressure. It is currently the only scientifically proven preventive measure against dementia. However, this should not prevent us from being as mentally, physically and socially active as possible and from eating healthily.

Prof. Nicola T. Lautenschlager
School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Perth, Australia