Support in daycare has an impact – including on the risk of dementia later on (symbolic photo). Photo: Shutterstock
The risk of dementia is proven to be increased by smoking, hearing loss, obesity, loneliness, air pollution and several other factors. Now a new report by the international Lancet Commission has expanded this list to include high cholesterol and declining eyesight. If all of the 14 modifiable risk factors listed were eliminated, almost half of the world’s dementia cases could be prevented or at least delayed, according to the report. But the calculation is not quite that simple.
No cure, but prevention
According to the German Alzheimer’s Society, an estimated 1.8 million people in Germany live with dementia. The term covers various diseases, including Alzheimer’s, which lead to a loss of mental abilities. There is currently no cure.
However, as the new report of the “Lancet Commission on dementia prevention, intervention, and care” states, 45 percent of dementia cases could be prevented or at least delayed if the 14 risk factors were eliminated. The international group had already presented twelve of these risk factors in 2020: low education, hearing loss, high blood pressure, smoking, obesity, depression, lack of exercise, diabetes, excessive alcohol consumption, traumatic head contusions, air pollution and social isolation.
The report has now added two further factors that are associated with nine percent of all dementia cases: an estimated seven percent of these are due to high LDL cholesterol levels from the age of about 40 and two percent are due to untreated vision loss in late life.
Conversely, this means: “If you correct the declining eyesight and reduce the LDL to optimal levels in middle age, you can actually reduce the risk of dementia,” explains Peter Berlit, Secretary General of the German Society of Neurology (DGN). These connections were to be expected, but have now been confirmed by the Lancet report – and should be taken into account in medical treatment by family doctors, for example.
Risk factors can reinforce each other
The neurologist emphasizes the interrelationships between the various risks: If the declining hearing and vision are not corrected in time, it affects communication, which has an impact on cognitive abilities and social interactions: “Regular cognitive training and loneliness are, in turn, factors that also play a role in the development of dementia.”
Berlit is accordingly cautious about the prevention potential quantified by the Lancet Commission: The 45 percent result from the addition of all the risk factors mentioned and under the assumption that these have been avoided since childhood: “That is of course unrealistic.” Nevertheless, significant effects could be achieved overall if each individual and politicians took appropriate measures.
Stefan Teipel from the German Center for Neurodegenerative Diseases (DZNE) in Rostock also says that the total number of preventable dementia cases across all risk factors is likely to be lower: “The study adds up the individual modifiable risks to just under 45 percent. However, if you influence several risk factors, there are synergistic effects, so you cannot simply add up the effects of risk reduction for individual individuals.”
What is good for the brain is also good for the heart
Berlit stresses that preventing dementia on an individual level does not just involve brain training in the form of crossword puzzles, learning foreign languages or musical instruments: “All of these are important. But it has also been proven that the right diet, for example in the form of the Mediterranean diet, as little alcohol as possible, sufficient physical exercise and a healthy body weight reduce the risk of dementia.” All of this benefits not only the brain, but also the heart. Such behavior could be encouraged in the form of bonus payments by funding bodies such as health insurance companies.
However, politicians are called upon to address risk factors such as air pollution and access to education – corresponding recommendations can also be found in the report. Children from disadvantaged families in particular need to be supported from kindergarten onwards, says Berlit.
Influence of education
Education actually has the greatest influence on the risk of dementia later in life – it is the only relevant factor in people under the age of 45. This is reported by the Doctors Newspaper.
Based on the available data, a low level of education explains around seven percent of all dementia cases worldwide. Only hearing loss has a higher weight, but this can hardly be influenced politically. “Politicians should therefore focus on children’s education above all else,” wrote the authors of the Lancet report in 2017. Whether someone develops dementia in old age therefore depends crucially on whether he or she has learned something at school. Low levels of education are associated with a 60 percent increased risk of dementia, but since low levels of education are widespread, this factor weighs more than most others.
Another political task in this context is to combat the consequences of the climate crisis, says neurologist Berlit: “We already know that the risk of stroke is increased by the lack of cooling at night.” In the area of dementia, the evidence is not yet large enough, but corresponding studies are already underway and will probably play a role in future Lancet reports.
Prevention from childhood
According to Berlit, it is important to take preventive measures at an age when dementia is not even being considered. To achieve this, it is crucial to make the contents of the report as widely known as possible. The doctor stresses: “Every individual must know that by changing their lifestyle they can actually make a significant contribution to minimising the risk of dementia, but also of other diseases.”
According to Frank Jessen, dementia prevention through a healthier lifestyle is already taking place: “The incidence of dementia has been decreasing in percentage terms in relation to age in many countries – including Germany – for years.” However, the number of older people is increasing rapidly, so that the total number of dementia sufferers is increasing slightly, according to the director of the Clinic for Psychiatry and Psychotherapy at the University Hospital of Cologne: “But if we lived an unhealthier lifestyle and paid less attention to things like blood pressure, exercise and nutrition, the number of dementia sufferers would be higher.”
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