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Because of the ageing of the general population and an increase in dementia patients, dementia was predicted to become a true epidemic. However, this assumption is based on data from twenty years ago. A review in The Lancet of recent epidemiologic publications concerning dementia epidemiology contradicts the conclusions previously made.

In the period of 1975 to 2010, the dementia prevalence has not significantly increased in the UK, Sweden and Spain. Indeed, in the UK a significant prevalence reduction of 22 percent was measured. Together with a decreasing dementia incidence in the Netherlands, all data point in the direction of a steady number of dementia patients.

According to Carol Brayne, lead author and professor of public health medicine at the University of Cambridge in the UK, these observations coincide with improvements in protective factors for dementia, such as education and living conditions, and a general reduction in risk factors, such as vascular diseases. “We are now potentially seeing the results of improvements in prevention and treatment of high blood pressure and cholesterol reflected in the risk of developing dementia."

The scientists suggest that the previously measured increase in dementia cases may partly be due to broader diagnostic criteria and detection of the disease at an earlier stage. Furthermore, the perspective of a high number of dementia patients needing medication is quite attractive to the pharmaceutical industry. In the UK, for example, 5 percent of research funding for dementia was dedicated to identification of risk factors and prevention, in contrast to 65 percent for the development of potential treatments.

Professor Brayne hopes the research outcomes will emphasise the effectiveness of prevention. “Our up-to-date evidence strengthens the need to shift more of our societal and research focus to primary prevention across the life course, with a rebalancing from what could be seen as the current overemphasis on diagnostics and drug interventions for dementia. Policies which address determinants of health in earlier life stages may have the greatest long term impact on reduction of dementia.”

Sources: The Lancet, Eurekalert

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