New data highlight the changing prevalence in dementia across the world – headlines from Alzheimer’s Association International Conference 2014

Five studies presented at the Alzheimer’s Association International Conference 2014 this week reveal the changing face of dementia prevalence across the world. The research suggests fewer new cases in developed nations, but underestimates of prevalence in low and middle income countries.

Posted on 15th July 2014

Five studies presented at the Alzheimer’s Association International Conference 2014 this week reveal the changing face of dementia prevalence across the world. The research suggests fewer new cases in developed nations, but underestimates of prevalence in low and middle income countries.

One presentation given by Kenneth Langa of the University of Michigan will review current evidence from several population-based studies suggesting a decline in dementia risk in the US, Rotterdam, Stockholm and England. While he is expected to discuss the suggested reasons for this decline, including better education and more aggressive treatment of vascular risk factors, he will also discuss the potential for rising cases of obesity and diabetes to threaten these improvements.

Researchers at the German Centre for Neurodegenerative Diseases will present findings that between 2007 and 2009, the number of cases of dementia among older German women fell, with a smaller decline seen in men. The relative risk of an individual developing dementia – also known as the incidence – also fell in men and women.

Researchers at Boston University School of Medicine will present findings from the Framingham Study, which followed volunteers over 60 in the US with assessments for risk factors, stroke and dementia. They defined four periods of time over the last three decades and found reductions in dementia incidence over the three most recent periods. This reduction was strongest in the youngest volunteers in the most recent time period, who were 60-69. During that time period, the researchers observed improvements in educational status, control of blood pressure and cholesterol, and in levels of smoking, heart disease and stroke. However during this time obesity and diabetes levels were increasing.

In contrast, a fourth study from researchers at Universidad Icesi in Colombia modelled prevalence of Alzheimer’s and other dementias in the country using updated population and prevalence estimates. Their results suggest that there could be as many as 220,000 people in Colombia with dementia in 2015, potentially twice as many as previous estimates.

In a separate review on global dementia prevalence by Alzheimer’s Disease International, updated figures were calculated for China and sub-Saharan regions of Africa. These were applied to the latest UN population projections and showed much higher dementia prevalence in these countries compared to previous estimates. The number of people living with dementia worldwide in 2013 was estimated at 44million.

Rebecca Wood, Chief Executive of Alzheimer’s Research UK, the UK’s leading dementia research charity, said:

“We know that age is the biggest risk factor for dementia and with ageing populations across many countries, the world is facing a dementia crisis. While there is no simple way to prevent the condition, it’s positive to see that improvements in health care for other conditions could be helping to stem the tide of dementia in developed nations. Time will tell whether rising trends in obesity and diabetes could set back this progress in the coming years.

“It is deeply concerning that the numbers of people affected by dementia in developing countries continue to spiral, with these nations likely to have the least resources available to support those affected and their loved ones. Dementia has a profound impact on individuals, families and the wider society and is one of the greatest health challenges of our time. Research is the key to understanding the condition and taking us towards better ways to reduce our risk, and Alzheimer’s Research UK has made a strong commitment to funding prevention research. This research shows that the threat of dementia is global and nations must join together in a concerted and coordinated effort to tackle it.”

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