Recent findings
Non-modifiable risk factors for dementia
Modifiable risk factors (lifestyle factors) for dementia







Dementia, including Alzheimer’s disease, remains one of the biggest global public health challenges facing our generation. There are some 800,000 people with dementia in the UK,1 with the burden falling on over-stretched social care services, the NHS and families. This number is expected to rise to over 1.7 million people by 2051.2 Dementia is one of the main causes of disability in later life in the UK, with symptoms including memory loss, confusion, problems with speech, understanding and control of emotions.

Dementia costs the UK economy £23 billion a year, while the worldwide cost in 2010, most of it in G8 countries, was estimated to be $604 billion (£365 billion) and the cost in low income countries is projected to grow significantly. Given this epidemic scale, and with no known cure, it’s crucial that we look at what we can do to reduce the risk or delay the onset of developing the disease.

In December 2013, the G8 nations—Canada, France, Germany, Italy, Japan, Russia, the UK, and the US—created the World Dementia Council (WDC)3 to provide global advocacy and leadership on key dementia challenges. One of the WDC’s priority areas is potential risk reduction, both in the absence of treatments and after the time at which a treatment or treatments become available. However, the WDC also recognised that any public health effort to address the risk factors of cognitive decline and dementia must be grounded in the scientific evidence and informed by the scientific literature. Both the World Health Organization and the G8 Dementia Summit of 2013 have stressed the need for prevention to curb the rapidly growing dementia epidemic.


Recent findings

Findings from a two-year study4 of more than 1,200 60 to 77-year-olds in Finland revealed that the group who received thorough advice about diet, regular exercise sessions, brain training and health check-ups performed better in cognitive tests than the group who received only the standard medical advice.

The goal of the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER), a proof-of-concept, randomised controlled trial, was to determine the impact of a multifaceted intervention aimed at preventing cognitive decline in at-risk elderly persons in the general population. Targeting multiple lifestyle factors, including physical activity, diet, vascular risk factors, and brain training, slowed cognitive decline among older healthy individuals in the first randomised controlled trial of its kind. Two meta analyses studies5,6 found that up to half of all dementia cases may be attributable to inactivity and vascular factors. They have both shown, in their meta-analyses studies, that aerobic physical activities that improve cardiorespiratory fitness enhance cognitive performance in sedentary older adults.

Lifestyle factors, such as poor diet and physical and cognitive inactivity, are thought to be associated with the risk of dementia.7 These factors may be useful targets for the prevention of cognitive impairment and dementia.

The Alzheimer’s Association believes there is sufficient evidence to support the link between several modifiable risk factors and a reduced risk for cognitive decline, and sufficient evidence to suggest that some modifiable risk factors may be associated with reduced risk of dementia.8

The Promoting Brain Health: Developing a prevention agenda linking dementia and noncommunicable diseases meeting was held in London in 2014. It involved some 60 leading figures in dementia and non-communicable disease (NCD) prevention—the first gathering of its kind—to discuss ideas for a primary prevention agenda on dementia. It concluded that while dementia might not be wholly preventable, like some other NCDs, it has some risk factors that are modifiable, and there is sufficient evidence to justify acting now on these.9

A comprehensive review of international research literature has identified that there are currently several factors that may protect a person from developing Alzheimer’s disease or delay its onset.10

NICE launched new recommendations in 2015 on approaches in mid-life to delay or prevent the onset of dementia, disability and frailty in later life. It concluded by changing specific risk factors and behaviours it is possible to reduce the risk of dementia, disability and frailty for many people.11


Non-modifiable risk factors for dementia

Age is the most important risk factor for cognitive decline and dementia.12 In addition, only a small proportion of dementia cases are thought to be directly inherited or caused by identified individual gene mutations.


Modifiable risk factors (lifestyle factors) for dementia


Mental activities
These include improvements in immediate and delayed recall.13,14

Social activities
Some individual studies have shown that higher social interaction in later life is associated with lower risk of developing cognitive impairment.15,16

Years of education
Among potentially modifiable risk factors, the most consistent evidence highlights years of formal education.17,18

Meta-analyses of cohort and longitudinal studies, as well as additional cohort studies, have shown a history of depression increases the risk for dementia.19,20

Several cohorts and observational studies link sleep disturbances (for example, insomnia and sleep apnoea) to increased risk for cognitive decline.21,22

Brain injury
A brain injury increases the risk of developing certain forms of dementia.23,24



Physical activities
Several randomised controlled trials and a Cochrane review of such trials have found that inactive, but otherwise healthy, seniors who begin an exercise programme experience significantly improved cognitive function.25,26

A few cohort studies on the Mediterranean diet (relatively little red meat with an emphasis on whole grains, fruits and vegetables, fish, nuts, and olive oil) or a combined Mediterranean-DASH (Dietary Approaches to Stop Hypertension) diet suggest an association between these diets and reduced risk.27,28

Meta-analyses of prospective and case control studies of older adults suggest small or moderate alcohol consumption by older individuals may decrease the risk of cognitive decline and dementia.29,30 The evidence is not strong enough, however, to suggest those who do not drink should start drinking, especially when weighed against the potential negative effects of excessive alcohol consumption, such as an increased risk of falls among older adults.31,32

One study of a large multi-ethnic cohort found heavy smoking in middle-age as much as doubled the risk of later-life dementia.33 Quitting smoking may reduce the associated risk to levels comparable to those who have not smoked.34,35,36



Some evidence suggests diabetes increases dementia risk not only through vascular pathways and interactions of other biological mechanisms related to diabetes itself.37,38

Mid-life obesity
Studies found that mid-life obesity is associated with an increased risk of dementia. Most postulate this is a strong link, especially with regard to cognitive decline.39,40,41,42 The association may change with age, as being overweight and, even possibly being obese in later life has been associated with reduced risk of dementia.44,45

Mid-life hypertension and hyperlipidaemia (elevated cholesterol) are other risk factors.



There is accumulating evidence from observational and experimental studies on how modifiable risk/ protective factors may relate to the pathological hallmarks of Alzheimer’s disease (ie. extracellular amyloid-β plaques and intracellular microtubule p-tau protein neurofibrillary tangles) as well as to the inflammatory and vascular components, of all types of dementias.20,47 The evidence has now reached a point that it can no longer remain simply an exercise in academic discussion. The public should know what the science concludes: certain healthy behaviours known to be effective for diabetes, cardiovascular disease, and cancer are also good for brain health and for reducing the risk of cognitive decline.

The evidence seemed to indicate that mid-life might be a particularly important period to target and there were suggestions that people at this stage of life might be especially receptive to welltargeted advice and interventions about delaying or preventing a process of cognitive decline.

Ideas put forward at the end of Promoting Brain Health meeting, May 2014, included screening and treatment by GPs for mid-life hypertension, screening for cognitive deficit at regular intervals over the age of 60 and making it routine in memory clinics to take blood samples to test for risk factor markers.

Based on the evidence, brain health promotion messages should be integrated in public health promotion campaigns such as anti-tobacco or noncommunicable disease (NCD) awareness campaigns, with the message that it’s never too late to make these changes. This report strongly suggests that dementia needs to be included on World Health Organization (WHO) and national NCD planning.47 To sum up, a good mantra is: “What is good for your heart is good for your brain.”


Dr Amir Sajjadi, Consultant Psychiatrist for the Elderly & Dementia Pathway Locality Lead Consultant, South West Community Mental Health Team, Tees, Esk and Wear Valleys NHS Foundation Trust

Professor Stephen Curran, Consultant in Old Age Psychiatry & Clinical Lead. Ground Floor, Modular Accommodation, Wakefield BDU, Fieldhead. Wakefield

Conflict of interest: none declared.



1. Promoting brain health: Developing a prevention agenda linking dementia and non-communicable diseases. Meeting report 20 May 2014. Available at Accessed on Sep 2015

2. Alzheimer Society. Available at: Document ID=412. Accessed on 25th November 2015

3. G8 Dementia Summit Communique. Available at: Accessed on Nov 2015

4. Ngandu T, Lehtisalo J, Solomon A, et al. A 2 year multidomain intervention of diet,exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. Lancet 2015; 385(9984): 2255–63

5. Barnes DE, Yaffe K. The projected effect of risk factor reduction on Alzheimer’s disease prevalence. Lancet Neurol 2011; 10: 819–28

6. Colcombe S, Kramer AF. Fitness effects on the cognitive function of older adults: a meta- analytic study. Psychol Sci 2003; 14: 125–30

7. Lövdén M, Xu W, Wang HX. Lifestyle change and the prevention of cognitivedecline and dementia: what is the evidence? Curr Opin Psychiatry 2013; 26(3): 239–43

8. Baumgart M, Snyder HM, Carrillo MC, et al. Summary of the evidence on modifiable risk factors for cognitive decline and dementia: A population-based perspective. Alzheimers Dement 2015; 11(6): 718–26

9. Promoting Brain Health: Developing a prevention agenda linking dementia and noncommunicable diseases. Meeting report 20 May 2014. Available at Accessed on Sep 2015

10. Targeting brain, body and heart for cognitive health and Dementia prevention: current evidence and future directions by Maree Farrow, Elodie O’Connor. On line version available at accessed on 27th November 2015

11. NICE guidelines: ‘Disability, Dementia and Frailty in Later Life - Mid-Life Approaches to Prevention’, available at: Accessed on 20th November 2015

12. Alzheimer’s Association. 2014 Alzheimer’s Disease Facts and Figures. Alzheimers Dement 2014; 10: e47–e92

13. Stern C, Munn Z. Cognitive leisure activities and their role in preventing dementia: a systematic review. Int J Evid Based Health 2010; 8(1): 2-17

14. Valenzuela M, Sachdev P. Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up. Am J Geriatr Psychiatry. 2009; 17(3): 179–87

15. James BD, Wilson RS, Barnes LL, Bennett DA. Late-life social activity and cognitive decline in old age. J Int Neuropsychol Soc. 2011; 17(6): 998–1005

16. Seeman TE, Miller-Martinez DM, Stein Merkin S, Lachman ME, Tun PA, Karlamangla AS. Histories of social engagement and adult cognition: midlife in the U.S. study. J Gerontol B Psychol Sci Soc Sci 2011; 66 Suppl 1: i141–52

17. Meng X, D’Arcy C. Education and dementia in the context of the cognitive reserve hypothesis: a systematic review with meta-analyses and qualitative analyses. PLoS One. 2012; 7(6): e38268

18. Beydoun MA, Beydoun HA, Gamaldo AA, et al. Epidemiologic studies of modifiable factors associated with cognition and dementia: systematic review and metaanalysis. BMC Public Health 2014; 14: 643

19. Ownby RL, Crocco E, Acevedo A, John V, Loewenstein D. Depression and risk for Alzheimer disease: systematic review, meta-analysis, and metaregression analysis. Arch Gen Psychiatry 2006; 63(5): 530–38

20. Barnes DE, Yaffe K, Byers AL, et al. Midlife vs late- life depressive symptoms and risk of dementia: differential effects for Alzheimer disease and vascular dementia. Arch Gen Psychiatry 2012; 69(5): 493–98

21. Yaffe K, Laffan AM, Harrison SL, et al. Sleep-disordered breathing, hypoxia, and risk of mild cognitive impairment and dementia in older women. JAMA 2011; 306(6): 613-19

22. Potvin O, Lorrain D, Forget H, et al. Sleep quality and 1-year incident cognitive impairment in communitydwelling older adults. Sleep 2012; 35(4): 491–99

23. Shively S, Scher AI, Perl DP, Diaz-Arrastia R. Dementia resulting from traumatic brain injury: what is the pathology? Arch Neurol 2012; 69(10): 1245–51

24. Lye TC, Shores EA. Traumatic brain injury as a risk factor for Alzheimer’s disease: a review. Neuropsychol Rev 2000; 10(2): 115–29

25. Angevaren M, Aufdemkampe G, Verhaar HJ, et al. Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment. Cochrane Database Syst Rev 2008: CD005381

26. Barnes DE, Santos-Modesitt W, Poelke G, Kramer AF, Castro C, Middleton LE, Yaffe K. The Mental Activity and eXercise (MAX) trial: a randomized controlled trial to enhance cognitive function in older adults. JAMA Intern Med 2013; 173(9): 797–804

27. Lourida I, Soni M, Thompson-Coon J, et al. Mediterranean diet, cognitive function, and dementia: a systematic review. Epidemiology. 2013; 24(4): 479–89

28. Morris, M.C., Tangney, C.C., Wang, Y., Sacks, F.M., Bennett, D.A., and Aggarwal, N.T. MIND diet associated with reduced incidence of Alzheimer’s disease. Alzheimers Dement. 2015. Available at : jalz.2014.11.009. accessed on 29th November 2015

29. Anstey KJ, Mack HA, Cherbuin N. Alcohol consumption as a risk factor for dementia and cognitive decline: metaanalysis of prospective studies. Am J Geriatr Psychiatry 2009; 17(7): 542–55

30. Neafsey EJ, Collins MA. Moderate alcohol consumption and cognitive risk. Neuropsychiatr Dis Treat 2011; 7:465–84.

31. Martin M, Clare L, Altgassen AM, Cameron MH, Zehnder F. Cognition-based interventions for healthy older people and people with mild cognitive impairment. Cochrane Database Syst Rev 2011;(1): CD006220

32. Mukamal KJ, Mittleman MA, Longstreth WT Jr, Newman AB, Fried LP, Siscovick DS. Selfreported alcohol consumption and falls in older adults: cross-sectional and longitudinal analyses of the cardiovascular health study. J Am Geriatr Soc 2004; 52(7): 1174–79

33. Rusanen M, Kivipelto M, Quesenberry CP Jr, Zhou J, Whitmer RA. Heavy smoking in midlife and long-term risk of Alzheimer disease and vascular dementia. Arch Intern Med 2011; 171(4): 333–39

34. Sabia S, Elbaz A, Dugravot A, et al. Impact of smoking on cognitive decline in early old age: the Whitehall II cohort study. Arch Gen Psychiatry 2012; 69(6): 627–35

35. McKenzie J, Bhatti L, Tursan d’Espaignet E. WHO Tobacco Knowledge Summaries: Tobacco and Dementia. World Health Organization, Geneva; 2014

36. Prince M, Albanese E, Guerchet M, Prina M. Dementia and Risk Reduction: An Analysis of Protective and Modifiable Factors. Alzheimer’s Disease International, London; 2014 (World Alzheimer’s Report 2014)

37. Mushtaq G, Khan JA, Kamal MA. Biological mechanisms linking Alzheimer’s disease and type-2 diabetes mellitus. CNS Neurol Disord Drug Targets.2014; 13(7): 1192–201

38. Yang Y, Song W. Molecular links between Alzheimer’s disease and diabetes mellitus. Neuroscience 2013; 250: 140–50

39. Sellbom KS, Gunstad J. Cognitive function and decline in obesity. J Alzheimers Dis. 2012; 30 Suppl 2: S89–95

40. Beydoun MA, Beydoun HA, Wang Y. Obesity and central obesity as risk factors for incident dementia and its subtypes: a systematic review and meta-analysis. Obes Rev 2008; 9(3): 204–18

41. Loef M, Walach H. Midlife obesity and dementia: metaanalysis and adjusted forecast of dementia prevalence in the United States and China. Obesity (Silver Spring) 2013; 21(1): E51-5.

42. Anstey KJ, Cherbuin N, Budge M, Young J. Body mass index in midlife and late-life as a risk factor for dementia: a meta-analysis of prospective studies. Obes Rev 2011; 12(5): e426–37

43. Gustafson DR, Bäckman K, Joas E, Waern M, Östling S, Guo X, Skoog I. 37 years of body mass index and dementia: observations from the prospective population study of women in Gothenburg, Sweden. J Alzheimers Dis 2012; 28(1): 163–71

44. Dahl AK, Löppönen M, Isoaho R, et al. Overweight and obesity in old age are not associated with greater dementia risk. J Am Geriatr Soc 2008; 56(12): 2261–66

45. Gustafson DR, Luchsinger JA. High adiposity: risk factor for dementia and Alzheimer’s disease? Alzheimers Res Ther 2013; 5(6): 57

46. Hughes TF, Ganguli M. Modifiable Midlife Risk Factors for Late-Life Cognitive Impairment and Dementia. Curr Psychiatry Rev 2009; 5(2): 73–92

47. World Alzheimer Report 2014Dementia and Risk Reduction 7 available at: accessed on 10th November 2015