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Alzheimer’s & dementia

How much each factor raises the risk of the dementia that ends lives. Tap a pill, answer yours; the same answers place you on the Dementia page. Green pills lower the risk, red raise it; a star marks an estimate, not a published number. All causes ›

Levers worth pulling

Not always the single biggest pill below, but each has a real study behind it and is still something you can do something about.

Factors behind Alzheimer’s death risk

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Factors behind Alzheimer’s death risk

50%25%0%25%50%75%100%← more risk · % change in risk · less risk →Factors, ranked by biggest effect1349%#1120%#2≈76%#312%60%#470%#570%#626%≈35%#760%#850%#949%#1044%#1140%#1240%#1330%#1430%#1530%#1626%#17≈4%20%#1823%#1923%#2023%#2122%#2220%#2320%#2420%#2519%#2610%#27Everythingelseno single number

Scroll sideways to see every factor →

Tap a pill to answer yours.

Where you sit

0 of 27 answered

Answer the 27 factors above to see which ones raise your own risk, which sit at the reference, and which the studies have no number for.

Factors behind Alzheimer’s death risk

45of 100

Out of 100 cases, how many each factor accounts for. Tap a segment, answer yours.

Next to each name: its share of the 100 cases, then you: your own answer’s effectraised for youcovered, or lower than the reference
7 · Untreated hearing loss7 · High LDL cholesterol5 · Less education5 · Social isolation3 · Depression3 · Head injury3 · Air pollution2 · Physical inactivity2 · Diabetes2 · Smoking2 · High blood pressure2 · Untreated vision loss1 · Obesity1 · Heavy drinking55 · Everything else100 cases0

Tap a segment to answer yours.

Relative risk versus each factor’s reference group; above the line is lower risk, below it higher.

Sources (28)Livingston G, Huntley J, Liu KY, et al., Lancet 2024 · Zhong et al., PLoS One 2015 · Yeo BSY, Song HJJMD, Toh EMS, et al., JAMA Neurol 2023 and 25 moreShow all
  1. [1]E. Genin et al. APOE and Alzheimer disease: a major gene with semi-dominant inheritance. Mol Psychiatry, 16(9):903-7, 2011. doi:10.1038/mp.2011.52 Evidence: Low
  2. [2]G. Livingston et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. Lancet, 404(10452):572-628, 2024. doi:10.1016/S0140-6736(24)01296-0 Evidence: Not graded (review)
  3. [3]S. A. Shumaker et al. Conjugated equine estrogens and incidence of probable dementia and mild cognitive impairment in postmenopausal women: Women's Health Initiative Memory Study. JAMA, 291(24):2947-58, 2004. doi:10.1001/jama.291.24.2947 Evidence: Moderate
  4. [4]S. A. Shumaker et al. Estrogen plus progestin and the incidence of dementia and mild cognitive impairment in postmenopausal women: the Women's Health Initiative Memory Study: a randomized controlled trial. JAMA, 289(20):2651-62, 2003. doi:10.1001/jama.289.20.2651 Evidence: Moderate
  5. [5]Y. Vinogradova et al. Use of menopausal hormone therapy and risk of dementia: nested case-control studies using QResearch and CPRD databases. BMJ, 374:n2182, 2021. doi:10.1136/bmj.n2182 Evidence: Low
  6. [6]N. Pourhadi et al. Menopausal hormone therapy and dementia: nationwide, nested case-control study. BMJ, 381:e072770, 2023. doi:10.1136/bmj-2022-072770 Evidence: Low
  7. [7]A. Sommerlad et al. Association of social contact with dementia and cognition: 28-year follow-up of the Whitehall II cohort study. PLoS Med, 16(8):e1002862, 2019. doi:10.1371/journal.pmed.1002862 Evidence: Low
  8. [8]D. A. R. Sutin et al. Sense of meaning and purpose in life and risk of incident dementia: New data and meta-analysis. Arch Gerontol Geriatr, 105:104847, 2023. doi:10.1016/j.archger.2022.104847 Evidence: High
  9. [9]C. A. C. Coupland et al. Anticholinergic Drug Exposure and the Risk of Dementia: A Nested Case-Control Study. JAMA Intern Med, 179(8):1084-1093, 2019. doi:10.1001/jamainternmed.2019.0677 Evidence: Low
  10. [10]K. H. Franks et al. Association of Stress with Risk of Dementia and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis. J Alzheimers Dis, 82(4):1573-1590, 2021. doi:10.3233/JAD-210094 Evidence: Low
  11. [11]L. Johansson et al. Midlife psychological stress and risk of dementia: a 35-year longitudinal population study. Brain, 133(Pt 8):2217-24, 2010. doi:10.1093/brain/awq116 Evidence: Low
  12. [12]B. S. Y. Yeo et al. Association of Hearing Aids and Cochlear Implants With Cognitive Decline and Dementia: A Systematic Review and Meta-analysis. JAMA Neurol, 80(2):134-141, 2023. doi:10.1001/jamaneurol.2022.4427 Evidence: High
  13. [13]M. Zuin et al. Risk of dementia in patients with atrial fibrillation: Short versus long follow-up. A systematic review and meta-analysis. Int J Geriatr Psychiatry, 36(10):1488-1500, 2021. doi:10.1002/gps.5582 Evidence: Moderate
  14. [14]G. Zhong et al. Smoking Is Associated with an Increased Risk of Dementia: A Meta-Analysis of Prospective Cohort Studies with Investigation of Potential Effect Modifiers. PLoS One, 10(3):e0118333, 2015. doi:10.1371/journal.pone.0118333 Evidence: High
  15. [15]Y. Leng et al. Association of Sleep-Disordered Breathing With Cognitive Function and Risk of Cognitive Impairment: A Systematic Review and Meta-analysis. JAMA Neurol, 74(10):1237-1245, 2017. doi:10.1001/jamaneurol.2017.2180 Evidence: Moderate
  16. [16]P. Iso-Markku et al. Physical activity as a protective factor for dementia and Alzheimer's disease: systematic review, meta-analysis and quality assessment of cohort and case-control studies. Br J Sports Med, 56(12):701-709, 2022. doi:10.1136/bjsports-2021-104981 Evidence: High
  17. [17]O. M. Shannon et al. Mediterranean diet adherence is associated with lower dementia risk, independent of genetic predisposition: findings from the UK Biobank prospective cohort study. BMC Med, 21(1):81, 2023. doi:10.1186/s12916-023-02772-3 Evidence: Low
  18. [18]S. Su et al. Leisure Activities and the Risk of Dementia. Neurology, 99(15), 2022. doi:10.1212/WNL.0000000000200929 Evidence: High
  19. [19]X. Qi et al. Dose-Response Meta-Analysis on Tooth Loss With the Risk of Cognitive Impairment and Dementia. J Am Med Dir Assoc, 22(10):2039-2045, 2021. doi:10.1016/j.jamda.2021.05.009 Evidence: Moderate
  20. [20]S. Asher et al. Periodontal health, cognitive decline, and dementia: A systematic review and meta-analysis of longitudinal studies. J Am Geriatr Soc, 70(9):2695-2709, 2022. doi:10.1111/jgs.17978 Evidence: Low
  21. [21]S. Sabia et al. Association of sleep duration in middle and old age with incidence of dementia. Nat Commun, 12(1):2289, 2021. doi:10.1038/s41467-021-22354-2 Evidence: Low
  22. [22]D. Hughes et al. Association of Blood Pressure Lowering With Incident Dementia or Cognitive Impairment: A Systematic Review and Meta-analysis. JAMA, 323(19):1934-1944, 2020. doi:10.1001/jama.2020.4249 Evidence: High
  23. [23]M. Eyting et al. A natural experiment on the effect of herpes zoster vaccination on dementia. Nature, 641(8062):438-446, 2025. doi:10.1038/s41586-025-08800-x Evidence: Low
  24. [24]M. Pomirchy et al. Herpes Zoster Vaccination and Dementia Occurrence. JAMA, 333(23):2083-2092, 2025. doi:10.1001/jama.2025.5013 Evidence: Low
  25. [25]M. Taquet et al. The recombinant shingles vaccine is associated with lower risk of dementia. Nat Med, 30(10):2777-2781, 2024. doi:10.1038/s41591-024-03201-5 Evidence: Low
  26. [26]L. Shi et al. Sleep disturbances increase the risk of dementia: A systematic review and meta-analysis. Sleep Med Rev, 40:4-16, 2018. doi:10.1016/j.smrv.2017.06.010 Evidence: Moderate
  27. [27]O. M. Bubu et al. Sleep, Cognitive impairment, and Alzheimer's disease: A Systematic Review and Meta-Analysis. Sleep, 40(1), 2017. doi:10.1093/sleep/zsw032 Evidence: High
  28. [28]M. Melville et al. Menopause hormone therapy and risk of mild cognitive impairment or dementia: a systematic review and meta-analysis. Lancet Healthy Longev, 6(12):100803, 2025. doi:10.1016/j.lanhl.2025.100803 Evidence: Low

Every factor, one by one

One quick question each. The charts above follow your answers, and so does every other What Matters page that asks the same question.

  1. #1APOE4 gene[1]Inherited+1349%

    The one common gene that moves Alzheimer’s risk by itself.

    Do you know your APOE status (from a genetic test)?

    reference
    +263%
    +1349%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  2. #2Depression[2]Midlife+120%

    The largest relative risk on this chart, though it affects fewer people.

    How often do you feel down or depressed?

    reference
    ≈+15%
    +120%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  3. #3Menopausal hormone therapy[3, 4, 5, 6]Women; timing matters≈+76%

    The one place a randomized trial exists: in the Women’s Health Initiative Memory Study, women who started oestrogen, with or without progestin, at 65 or older developed 1.76 times the probable dementia of the placebo group (combined therapy 2.05; oestrogen alone 1.49, not significant).

    Have you used hormone therapy (HRT) for the menopause?

    reference
    +24%
    ≈+76%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  4. #4Social isolation[2, 7]Later life+60%

    Infrequent contact with other people in later life.

    How connected are you to friends and family?

    −12%
    reference
    +60%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  5. #5Head injury[2]Midlife+70%

    A traumatic brain injury at any point raises later dementia risk, and more or worse injuries raise it more.

    Have you ever had a head injury that knocked you out or left you concussed?

    reference
    +70%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  6. #6Diabetes[2]Midlife+70%

    Type 2 diabetes in midlife raises dementia risk by about 70%, with longer duration and poorer control raising it more.

    What’s your blood sugar like?

    reference
    ≈+20%
    +70%
    +70%
    no number

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  7. #7Sense of purpose[8]Later life≈+35%

    People who feel their life has meaning develop less dementia.

    Do you feel a sense of purpose in your life?

    −26%
    reference
    ≈+35%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  8. #8Less education[2]Early life+60%

    Fewer years of schooling early in life means less cognitive reserve to draw on when brain changes start.

    How far did you get in school?

    +60%
    reference
    reference

    Same number, 2 answers: The Commission’s indicator is secondary education or more versus less; it prints no separate, better-than-reference figure for education beyond secondary school. More schooling plausibly helps further, but this chart’s own scale has no protective anchor below the reference to place it at, so it shares the reference rather than a fabricated dip.

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  9. #9Untreated vision loss[2]Later life+50%

    [2]: visual impairment that goes uncorrected.

    How well do you see day to day?

    reference
    ≈+15%
    +50%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  10. #10Strong anticholinergic medicines (Benadryl, Unisom and others)[9]Midlife and later+49%

    These drugs block acetylcholine, the messenger the memory system runs on and the one Alzheimer’s drugs try to boost.

    Do you take strong anticholinergic medicines? Common ones: Benadryl (diphenhydramine), Unisom and other “PM” sleep aids (doxylamine), promethazine, hydroxyzine, bladder drugs like oxybutynin or tolterodine, older antidepressants like amitriptyline, and some antipsychotics or Parkinson’s drugs.

    reference
    +6%
    +49%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  11. #11Chronic stress[10, 11]Midlife+44%

    Feeling stressed most of the time in adulthood goes with more dementia later, through cortisol, sleep, blood pressure, and mood.

    How stressed are you day to day?

    reference
    ≈+22%
    +44%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  12. #12Untreated hearing loss[2, 12]Midlife+40%

    The largest single midlife factor.

    How is your hearing in conversation?

    reference
    +40%
    ≈+13%
    +40%
    no number

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  13. #13Atrial fibrillation[13]Later life+40%

    An irregular heartbeat lets tiny clots and pressure swings reach the brain, so it raises dementia even in people who never have a stroke.

    Have you been diagnosed with atrial fibrillation (an irregular, often fast heartbeat)?

    reference
    +40%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  14. #14High LDL cholesterol[2]Midlife+30%

    Tied with hearing for the largest effect.

    What’s your cholesterol like?

    reference
    ≈+15%
    ≈+15%
    +30%
    no number

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  15. #15Smoking[14]Midlife+30%

    Current smokers carry about 30% more dementia risk than people who never smoked.

    Do you smoke?

    reference
    +1%
    +30%
    +30%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  16. #16Obesity[2]Midlife+30%

    A body mass index of 30 or more in midlife.

    How would you describe your weight?

    +30%
    +30%
    ≈+8%
    reference
    ≈+15%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  17. #17Sleep apnea[15]+26%

    Sleep-disordered breathing (loud snoring with pauses or gasping) was linked to about a quarter more cognitive impairment, including dementia, across 14 cohorts.

    Do you snore loudly or wake up gasping?

    reference
    ≈+10%
    ≈+13%
    +26%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  18. #18Physical inactivity[2, 16]Midlife+20%

    Regular exercise protects the brain through blood flow, blood pressure, sleep, and mood.

    How many days a week do you get 30+ minutes of exercise?

    +20%
    ≈+10%
    reference
    ≈−4%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  19. #19Mediterranean-style diet[17]Midlife−23%

    In 60,000 UK Biobank adults followed for nine years, the third eating closest to a Mediterranean pattern (vegetables, legumes, fruit, nuts, olive oil, fish; little processed or red meat) developed 23% less dementia than the third furthest from it, with or without a high genetic risk.

    How would you describe your diet?

    reference
    ≈−8%
    ≈−15%
    −23%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  20. #20Mentally active leisure[18]Later life−23%

    Across 38 cohorts and two million people, the most mentally active in their leisure time developed 23% less dementia than the least active; the same review found smaller effects for physical (17%) and social (7%) leisure.

    How often do you do things for fun that make you think hard (reading, puzzles, games, learning something, an instrument)?

    reference
    ≈−12%
    −23%

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  21. #21Gum disease and tooth loss[16, 19, 20]Midlife+23%

    Chronic gum infection keeps inflammation running for decades and lets mouth bacteria into the blood; the bug behind periodontitis has been found in Alzheimer’s brains.

    How are your teeth and gums?

    reference
    +21%
    +23%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  22. #22Short sleep[21]Midlife+22%

    Sleeping six hours or less a night at 50 was linked to more dementia over the next 25 years in Whitehall II, independent of mood, heart health, and social factors.

    How much sleep do you usually get?

    +22%
    ≈+10%
    reference
    ≈+20%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  23. #23High blood pressure[2, 22]Midlife+20%

    Untreated high blood pressure in midlife damages the small vessels that feed the brain.

    What’s your blood pressure like?

    reference
    ≈+10%
    ≈+12%
    +20%
    no number

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  24. #24Heavy drinking[2]Midlife+20%

    More than 21 UK units a week, roughly ten pints or two bottles of wine.

    How much alcohol do you drink?

    reference
    ≈+4%
    ≈+10%
    +20%

    Not answered yet. Tap an option to save your answer. Saved to your quiz answers, so the quiz shows it too.

  25. #25Shingles vaccine[23, 24, 25]Later life−20%

    The strongest new lead in dementia prevention.

    Have you had a shingles vaccine?

    reference
    −20%
    −20%
    ≈−10%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  26. #26Poor sleep quality[26, 27]Later life+19%

    Trouble sleeping, apart from how long you sleep and whether you snore (those are their own pills), is linked to more dementia, partly because deep sleep is when the brain clears amyloid.

    How well do you usually sleep?

    reference
    ≈+10%
    +19%

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

  27. #27Air pollution[2]Later life+10%

    A small relative risk applied to most of the population: three quarters of people live with fine-particle levels above the WHO guideline.

    What is the air like where you live?

    reference
    +10%
    no number

    Not answered yet. Tap an option to save your answer. This answer does not change your life estimate.

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Dementia risk deep dive ›Alzheimer's deep dive ›Sleep quiz ›