Cases of dementia in the world will grow because the population ages, but the prevalence by age continues to decrease and makes things less obvious.
Last January he had made a lot of sensation, in the USA, a study that stated that the risk for US citizens over 55 to develop a form of dementia in life was 42%. Based on research, published on Nature Medicine and also resumed by us at Evidence Network.itif the hypothesis were true it would mean coming to one million new cases per year of dementia of various types by 2060about twice the current ones.
The reason is undeniable: you live longer and longer and the world population ages. But are you sure that the cases will even double?
If nothing changes. According to several studies mentioned in an article published on New York Timesthe estimates traced by that study of various American universities including the Nyu Langone Health would be pessimistic and incorrect, because they take on that The prevalence of dementia in old age will remain stable for the next 40 years. And therefore, as i baby boomers They age and that the population of the over 80 increases, the new diagnoses of dementia will grow with the disruptive charge of a tsunami.
Each generation a little better. However, it is not at all said that things should go like this. Also because it wasn’t like that until now. A study by Duke University published on Jama points out that the prevalence of dementia in the United States has constantly decreased over the past 40 years.
Based on detailed calculations in the research, cases of dementia are still intended to increase, since it is Diseases affecting the elderly population and considered the aging of the population. But they will increase More than 10-25% from here to 2050because, “if your risk is lower than that of your parents and this trend continues, we will not witness a doubling or a triple of cases of dementia as it was projected”, explains Murali Doraiswamy, director of the program of neurocognitive disorders of Duke University and co -author of the study.
Prevalence in decline. To give an example, in the 85-89-year-old cohort among the long-term study participants launched by Duke University, which included 21,000 subjects in 1984 and 16,000 in 2004, the proportion of people with dementia was about 23% among those born in 1905. Among the born in 1915 (15 years later), it had dropped to 18%. When the born in 1935 reached the end of the decade of 80 years, about 11% had forms of dementia. The projection, for those born from 1945 to 1949, is about 8%.
Not only in the USA. Another longitudinal study (which analyzes the changes of a phenomenon over time) on the elderly of the United Kingdom and China published last year on Nature Aging highlighted important improvements in the prevalence of dementia in the most recent birth cohorts. Found in other works also in different European countries. But what do you do due to what?
Steps forward (and steps back). Among the possible explanations we find the improvement of the levels of education, the reduction of smoking habit, the progress in the treatment of hypertension and high cholesterol. Other factors still have a high improvement potential, such as the reduction of air pollution and the spread of low -price hearing aids to bring out people who feel little from isolation. There are also variables that could worsen the situation, such as the spread of obesity and diabetes, although contrasted by the receptor agonist drugs of the GLP-1 (provided that they can spread in a “democratic” way).
A matter of choices. In short, the situation seems more fluid and dynamic than the previous photograph. And public health policies can make a substantial difference. For example, enchant the air With pollution from fossil sources it would also cause a greater prevalence of dementia. They would do health policies that exacerbate inequalities rather than to smooth out.
