A new European study published in the journal Neurology shows the risk of developing dementia may have declined over the past 20 years, in direct contrast to what many have previously assumed.
The long term study based in Sweden monitored the ageing and health of over 3,000 participants aged 75 and over during a two decade period; 523 of those participants were diagnosed with some form of dementia. Key members of The Kungsholmen Project, named after the central Stockholm city in which the study was based, remained constant since the research began in1987, including the neurologist responsible for the clinical diagnosis of dementia. Each of the 3,000 study participants were assessed by a nurse, a physician and a psychologist.
In contrast to the common assumption that the risk of developing dementia will rise, the findings from the Swedish study in Stockholm are surprising. The research conducted by the Ageing Research Centre shows that despite the survival rates of dementia sufferers increasing since the 1980’s, the occurrences of dementia have shown to stabilize. These findings have led researchers to conclude that the overall risk of developing dementia has declined during this period with improvements in heart health thought to be a major contributing factor.
“We know that cardiovascular disease is an important risk factor for dementia. The suggested decrease in dementia risk coincides with the general reduction in cardiovascular disease over recent decades,” says Associate Professor Chengxuan Qiu of the Ageing Research Center, established by Karolinska Institutet and Stockholm University. “Health check-ups and cardiovascular disease prevention have improved significantly, and we now see results of this improvement reflected in the risk of developing dementia.”
Dementia, characterized by impaired memory and other mental functions is a devastating illness with a high personal and societal cost. The initial signs of dementia, which is caused by diseases of the brain, may include short-term memory loss that affects every day life, problems with thinking or reasoning, or unexplained anxiety, anger or depression. According to the Monetary Cost of Dementia in the United States report, the yearly monetary cost per person that was attributable to dementia could be as high as $56,290.
In the UK alone, the Alzheimer’s Society estimates that 800,000 people in the UK have a form of dementia and more than half have Alzheimer’s disease. The figure is estimated to rise to a million by 2021 due to an increase in survival rates of dementia sufferers and an ever increasing ageing population.
“The reduction of dementia risk is a positive phenomenon, but it is important to remember that the number of people with dementia will continue to rise along with the increase in life expectancy and absolute numbers of people over age 75”, says Laura Fratiglioni, professor and director of the Ageing Research Center. “This means that the societal burden of dementia and the need for medical and social services will continue to increase. Today there’s no way to cure patients who have dementia. Instead we must continue to improve health care and prevention in this area.”
The study was funded by the Swedish Council for Working Life and Social Research (FAS ), the Swedish Ministry of Health and Social Affairs, the Swedish Research Council, and Swedish Brain Power.
Publication: ‘Twenty-year changes in dementia occurrence suggest decreasing incidence in central Stockholm, Sweden’, Chengxuan Qiu, Eva von Strauss, Lars Bäckman, Bengt Winblad, Laura Fratiglioni, published in the April 17, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurology, doi: 10.1212/WNL.0b013e318292a2f9.
Monetary Cost of Dementia http://www.nejm.org/doi/full/10.1056/NEJMsa1204629
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