alzhub.org
Get help now — free helplines

You can call any of these for free. You do not need a diagnosis, an appointment, or a crisis to call — questions and plain exhaustion are reasons enough.

  • Alzheimer's Association 24/7 Helpline 800-272-3900 24 hours a day, 365 days a year Free, confidential support and information for people with dementia, caregivers, families and the public. Master's-level clinicians. Also Spanish.
  • 988 Suicide & Crisis Lifeline 988 24/7 Call or text 988, or chat at 988lifeline.org. For anyone in emotional distress or a mental-health crisis, including caregivers.
  • Alzheimer's Foundation of America (AFA) Helpline 866-232-8484 9:00 am - 9:00 pm ET, seven days a week Licensed social workers providing support, info and referrals. Also text message and web chat. Text: 646-586-5283

In a medical emergency, call 911. More numbers, and what each line does, on the help page.

Home › Research › What the research found › Every row

Every row of the evidence table

One row per finding: what was tested, which way the result went, and how the study was built. The answer by area, and where the studies disagree, are on the main page.

Every row

Filter

Area All 382 Care, carers and services 140 Medicines 85 Genes (not modifiable) 35 All modifiable factors together 27 Diet and supplements 23 Exercise and activity 21 Sleep, mood and social life 19 Hearing and vision 8 Alcohol, tobacco and cannabis 6 Infection and vaccination 5 Heart and metabolic health 4 Injury, delirium and falls 4 Environment 3 Cognitive activity 2
Question Both Prevention 190 Treatment 192
Direction Any Benefit 144 Harm 105 No effect 38 Mixed 37 No direction reported 58
Design Any meta-analysis 57 randomised trial 44 phase 3 trial 15 systematic review 9 phase 2 trial 10 cohort study 136 phase 1 trial 2 cross-sectional study 31 case-control study 14 modelling study 20 regulatory decision 7 company announcement 1 coverage determination 1 None 35
Clear all

Showing 10 of 382 rows. One row per study per exposure: a study that tested two different things appears twice, once for each.

Scroll the table sideways to see every column.

Research and outcomes, 10 rows. Every row links to its source.
Exposure Question Direction Outcome measured Design People Effect size, as the source reported it Source
Antihypertensives / BP lowering Medicines Prevention Benefit
why

Significant for MCI and for the MCI-or-dementia composite; not significant for probable dementia alone (HR 0.86, 95% CI 0.72-1.02).

 MCI and probable dementia over median 7 years randomised trial 9,361 Probable dementia: 8.5 vs. 10.2 per 1,000 person-years (HR 0.86, 95% CI 0.72-1.02); MCI: HR 0.87 (95% CI 0.76-1.00); composite MCI-or-dementia: HR 0.89 (95% CI 0.79-0.99) Neurology 2025
✓ Peer-reviewed PMID 39819096
Antihypertensives / BP lowering Medicines Prevention Benefit
why

A large drop in blood pressure (22/9 mmHg) and fewer serious adverse events in the intervention villages.

 All-cause dementia over 48 months randomised trial 33,995 All-cause dementia RR 0.85 (95% CI 0.76-0.95) Nature Medicine 2025
✓ Peer-reviewed PMID 40258956
Antihypertensives / BP lowering Medicines Prevention Benefit
why

Individual participant data from five double-blind placebo-controlled trials, which is the strongest design in this table for this exposure.

 Incident dementia over a median 4.3 years meta-analysis 28,008 Adjusted OR 0.87 (95% CI 0.75-0.99) for incident dementia European Heart Journal 2022
✓ Peer-reviewed PMID 36282295
Antihypertensives / BP lowering Medicines Prevention Benefit
why

Consistent across 14 trials (I-squared 0%) but small in absolute terms: 0.39 percentage points over about 4 years.

 Incident dementia or cognitive impairment meta-analysis 96,158 OR 0.93 (95% CI 0.88-0.98); absolute risk reduction 0.39% over 4.1 years JAMA 2020
✓ Peer-reviewed PMID 32427305
GLP-1 receptor agonist Medicines Prevention Benefit
why

Seven separate comparisons against seven other antidiabetic drugs, so the comparator is always another drug rather than no treatment.

 First-time Alzheimer's diagnosis over 3 years cohort study 1,094,761 HR 0.33 (95% CI 0.21-0.51) vs. insulin; HR 0.59 (95% CI 0.37-0.95) vs. other GLP-1 agonists Alzheimer's & Dementia 2024
✓ Peer-reviewed PMID 39445596
Metformin / antidiabetic Medicines Prevention Benefit
why

Heterogeneity was near-total (I-squared 98.9%) and the estimate went to null in people newly diagnosed with diabetes (HR 1.01), which is where prevalent-user bias would be smallest.

 Incident dementia meta-analysis 3,463,100 HR 0.76 (95% CI 0.65-0.91) vs non-users overall; HR 1.01 (0.81-1.27) in newly diagnosed diabetes Diabetes, Obesity and Metabolism 2025
✓ Peer-reviewed PMID 39780315
Metformin / antidiabetic Medicines Prevention Benefit
why

Comparator is other oral antidiabetic drugs, not no treatment.

 All-cause dementia and Parkinson's disease cohort study 358,862 All-cause dementia aHR 0.79 (95% CI 0.69-0.90) for SGLT2 inhibitor vs other oral antidiabetic drugs Neurology 2024
✓ Peer-reviewed PMID 39292986
Metformin / antidiabetic Medicines Prevention Benefit
why

The exposure actually studied is STOPPING metformin early, which carried 21% higher dementia incidence than staying on it. Read as indirect support for metformin, not as a trial of it.

 Incident dementia cohort study 41,346 HR 1.21 (95% CI 1.12-1.30) for dementia after early metformin termination JAMA Network Open 2023
✓ Peer-reviewed PMID 37878309
SGLT2 inhibitor Medicines Prevention Benefit
why

For SGLT2 inhibitors specifically: HR 0.86 (95% CI 0.79-0.94) against DPP4 inhibitors, and HR 0.70 in the as-treated analysis.

 Incident dementia cohort study not stated SGLT2i vs DPP4i HR 0.86 (95% CI 0.79-0.94); GLP1-RA vs DPP4i HR 0.95 (0.87-1.04) Alzheimer's Research & Therapy 2025
✓ Peer-reviewed PMID 41420258
Statins / lipid-lowering Medicines Prevention Benefit
why

Benefit was confined to APOE4 carriers (HR 0.60) and absent in non-carriers (HR 0.96). Observational, and it disagrees with the larger target-trial emulation that found nothing.

 Incident clinical Alzheimer's disease and cognitive decline cohort study 4,807 Alzheimer's HR 0.81 (95% CI 0.70-0.94) overall; 0.60 (0.49-0.74) in APOE ε4 carriers; 0.96 (0.82-1.12) in non-carriers Neurology 2024
✓ Peer-reviewed PMID 38447103

How this table was built, and where it is weak →