Experts name new risk factors for dementia
Dementia is becoming an increasingly significant issue, making it crucial to intervene early. A renowned commission has identified twelve risk factors for this neurodegenerative disease so far, with two new ones recently added.
The risk of dementia has been proven to increase due to factors such as smoking, obesity, loneliness, air pollution, and others. A new report from the international Lancet Commission has now expanded this list to include high cholesterol levels and declining vision. If all fourteen modifiable risk factors were eliminated, approximately half of global dementia cases could be prevented or delayed, according to the report. However, the calculation is not quite that simple.
No cure, but prevention is possible
According to the German Alzheimer's Association, around 1.8 million people in Germany are estimated to be living with dementia. The term encompasses various diseases, including Alzheimer's, which lead to a loss of cognitive abilities. There is currently no cure.
As stated in the new report by the "Lancet Commission on dementia prevention, intervention, and care," 45 percent of dementia cases could be prevented or delayed if these fourteen risk factors were eliminated. In 2020, this international group presented twelve of these risk factors: low education, hearing loss, high blood pressure, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol consumption, traumatic brain injuries, air pollution, and social isolation.
The report has now added two more factors linked to nine percent of all dementia cases: approximately seven percent can be attributed to high LDL cholesterol levels from around the age of 40, and two percent to untreated late-life vision loss.
Risk factors can reinforce each other
In other words, if declining vision is corrected and LDL levels are optimized in midlife, the risk of dementia can actually be reduced, explains Peter Berlit, General Secretary of the German Society of Neurology (DGN). These connections were expected but are now confirmed by the Lancet report and should be considered in medical treatment, for example, by general practitioners.
The neurologist emphasizes the interconnections between different risks: if declining hearing and vision are not corrected in time, they can affect communication, which in turn impacts cognitive abilities and social interactions. "Regular cognitive training and social isolation are also factors that play a role in dementia development."
Regarding the prevention potential estimated by the Lancet Commission, Berlit is cautious: the 45 percent figure is based on the sum of all mentioned risk factors and assumes that these have been avoided since childhood: "Of course, that's unrealistic." Nevertheless, significant effects could be achieved if individuals and politics take appropriate measures.
Even Stefan Teipel from the German Center for Neurodegenerative Diseases (DZNE) in Rostock agrees 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 nearly 45 percent. However, there are synergistic effects when several risk factors are influenced, so the effects of risk reduction cannot simply be added up for individual individuals."
What's good for the brain is also good for the heart
Berlit emphasizes that dementia prevention at the individual level does not only involve brain training such as crossword puzzles, learning foreign languages, or playing musical instruments: "All of this is important. However, it is also proven that proper nutrition, such as the Mediterranean diet, minimal alcohol consumption, adequate physical activity, and a healthy body weight can reduce the risk of dementia." All of this is beneficial not only for the brain but also for the heart. Such behavior could be encouraged through bonus payments by health insurers.
Politicians, on the other hand, are called upon to address risk factors such as air pollution and access to education - corresponding recommendations can also be found in the report. In particular, children from disadvantaged families should be supported from an early age, says Berlit. Another political task in this context is to combat the consequences of the climate crisis: "We already know that the risk of stroke is increased by the lack of nighttime cooling." In the field of dementia, the evidence is not yet sufficient, but relevant studies are already underway and are likely to play a role in future Lancet reports.
Prevention from childhood
Berlit emphasizes that preventive measures should be taken at an age when dementia is not yet a concern. To this end, it is crucial to make the contents of the report as widely known as possible. The doctor underscores: "Everyone must know that they can make a significant contribution to risk minimization against dementia, but also against other diseases, by changing their lifestyle."
Such dementia prevention through a healthier lifestyle is already taking place, according to Frank Jessen: "The prevalence of dementias is decreasing in many countries, including Germany, in terms of age percentage." However, the number of older people is increasing rapidly, so the total number of dementia cases is still rising slightly, says the director of the Clinic for Psychiatry and Psychotherapy at the University of Cologne: "If we were to live less healthily and pay less attention to factors such as blood pressure, exercise, and nutrition, the numbers of dementia cases would be higher."
What impact a reduction in risk factors could have in Germany was calculated by a German research group last year. Their study, published in the "German Medical Journal," found that if those factors could be reduced by 15 percent by 2033, it would reduce the number of dementia cases by 138,000 or 15 percent. "Behind every dementia case is a tragedy, for the affected person, their relatives, and the solidarity community in terms of disease costs. What an impact!", explains Steffi Riedel-Heller, director of the Institute for Social Medicine, Occupational Medicine, and Public Health (ISAP) at the University of Leipzig. And she calls for a "Brain Health Agenda" in Germany to bring this knowledge about modifiable risk factors to the people and, in particular, to decision-makers in politics and society.
The new report from the Lancet Commission has now added high LDL cholesterol levels and declining vision as two more risk factors for the disease, contributing to approximately seven percent and two percent of all dementia cases respectively. If these additional risk factors are addressed, there could be a reduced risk of dementia, as stated by Peter Berlit.
By addressing these modifiable risk factors, significant effects on dementia prevention can be achieved, according to Stefan Teipel. However, the total number of preventable dementia cases across all risk factors may be lower due to synergistic effects when several risk factors are influenced.
