Dementia risk reduction

Our position on the use of scientific evidence to support public policies aimed at dementia risk reduction.

Dementia risk reduction policy statement

Background

Dementia has many causes but it is increasingly clear that a mixture of genetic, lifestyle and health factors are likely to contribute to whether someone develops dementia at a particular age. Recent research suggests that there are risk factors which can be modified throughout life leading to lower risk of dementia in later life. The risk of developing dementia increases steeply after the age of 65, however recent encouraging evidence suggests that the age-specific prevalence of dementia may have decreased over the past 20 years[1]. This prompts the question of why such a decrease has taken place, and how changes in exposure to adverse factors throughout life might delay or even prevent dementia[2].

Increasing evidence to support risk reduction and dementia

Most dementia occurs in older people.  Based on current evidence, modelling suggests that seven modifiable risk factors might explain around a third of Alzheimer’s disease cases[3]. Much of the data has come from observational studies where large numbers of individuals are followed over time to reveal associations between particular risk factors and dementia risk. While these studies do not confirm that the risk factor has a direct, ‘causal’ effect on dementia risk, the relationship can potentially be tested through randomised controlled interventional trials. To date, there have been few trials of interventions due to methodical difficulties and the long timeframes needed to study impact on dementia risk reduction.

 Recent systematic reviews[4] agree that key risk factors for dementia are smoking, high blood pressure, obesity, diabetes and education in early life.  These broadly mirror the key risk factors for cardiovascular disease. Thus healthy lifestyles, which minimise future cardiovascular risk from a young age, are also likely to help reduce the future risk of dementia. Healthy lifestyle changes made in mid-life (such as increasing physical activity and stopping smoking) could still reduce dementia risk in later life. Other protective factors such as mentally stimulating activity and social engagement also appear to help reduce the risk of developing dementia[5].

Although other factors have been suggested (such as eating certain foods or taking particular supplements), the supporting evidence is weak or non-existent[6], and side-effects of long term exposure is unknown.

Current policy actions

The Blackfriars Consensus, a multi-organisational statement on reducing the risk of dementia, was published in May 2014[7] and signed by Alzheimer’s Research UK. This and other consensus statements[8] suggest that there is sufficient scientific evidence to enable people to begin to act to reduce their risk of dementia. Since the publication of the Blackfriars Consensus there has been considerable political and policy-making interest in the potential to reduce the risk of dementia:

  • Dementia risk reduction with improved public messaging is one of the key aspirations for the Challenge on Dementia 2020[9].
  • Dementia risk reduction is one of the seven priority areas for Public Health England’s strategy for the next five years[10].
  • NICE has published public health guidance on mid-life actions to reduce the risk of dementia and frailty in later life[11].
  • Public Health England, in conjunction with Alzheimer’s Research UK and Alzheimer’s Society has undertaken a pilot study to assess the feasibility of extending the dementia component of the NHS Health Check to include 40-64 year olds, offering information to help this group of people understand the measures they can take to help reduce their risk of dementia.

Our Policy

  • We are committed to improving the understanding of the risk factors associated with dementia, in terms of their significance, impact and ways to mitigate the risk.
  • We recognise that while there is some existing evidence, there is an urgent need for more detailed and robust research in this area.
  • Given the current lack of public awareness, we support campaigns that seek to improve public understanding of dementia risk. It is particularly important that there is engagement with the public in mid-life (40-60 years old) when the evidence suggests changes to health and lifestyle might have most impact.
  • We recognise that while individuals can make changes to reduce their risk, responsibility also lies with national and local government to create environments that affect risk factors such as physical activity, smoking and healthy eating, and to encourage civil societies that promote protective factors such as education. Such action should reflect inequalities in the broadest sense and recognise the potential impact inequalities may have on the risk of developing dementia.
  • We intend to work with policy makers, public health professionals and clinicians to improve their understanding of how lifestyle factors might change a person’s risk of developing dementia.

Future actions

To date there has been relatively little funding for research into the impact of risk factors on dementia. Alzheimer’s Research UK is addressing this gap by launching a Prevention and Risk Reduction Fund to answer the biggest questions in prevention, seed-funding the best ideas. With our commitment and focus on research we are ideally placed to lead this work.

Alzheimer’s Research UK has a public information leaflet about reducing the risk of developing dementia, developed with Public Health England.

This policy statement is part of a broader programme of work by Alzheimer’s Research UK to highlight the possible importance of lifestyle factors in reducing the risk of dementia.

References

[1] Matthews, F. E. et al (2013) A two-decade comparison of prevalence of dementia in individuals aged 65 years and older from three geographical areas of England: results of the Cognitive Function and Ageing Study I and II. The Lancet, 1405-12.

[2] Banerjee, S. (2013) Good news on dementia – we can make a difference. The Lancet, 1384-1386.

[3] Norton, S. et al (2014). Potential for primary prevention of Alzheimer’s disease: an analysis of population-based data. The Lancet Neurology 13.8 (2014): 788-794.

[4] Alzheimer’s Disease International (2014) The World Alzheimer Report 2014, Dementia and risk reduction: analysis of protective and modifiable factors.

[5]  Valenzuela, M.J. and Sachdev, P (2006). Brain reserve and dementia: a systematic review. Psychological Medicine, pp 441-454. doi:10.1017/S0033291705006264.

[6] Sydenham, E. et al (2012) Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database Systematic Review, Jun 13;6:CD005379.

[7] UK Health Forum and Public Health England (2014) Blackfriars Consensus on Promoting Brain Health.

[8] Orrell, M. et al (2015) Dementia prevention: call to action. The Lancet , Volume 386 , Issue 10004 , 1625

[9] Department of Health (2015) Prime Minister’s challenge on dementia 2020.

[10] Public Health England (2014) From evidence into action: opportunities to protect and improve the nation’s health.

[11] NICE (2015) Dementia, disability and frailty in later life – mid-life approaches to delay or prevent onset. NICE guidelines [NG16]