Dementia
Supplements studied for dementia.
Overview
No supplement here shows clear treatment benefit for established dementia. Melatonin (WA 56; low effect size, very high evidence, medium trust; 10 studies) did not improve cognition or daily behavior in most trials, though low-dose nightly use may ease sundowning in some studies.
Green Tea, Caffeine, and Black Tea appear mainly in observational prevention research with low trust. Higher green tea intake and midlife caffeine consumption have been linked to lower later dementia risk in some cohorts, but findings are not consistent across populations. Branched Chain Amino Acids (BCAAs) blood levels correlate with lower risk in one analysis. See the heatmap and evidence reviews below.
Effect graph
Relevant supplements
Relevant supplements sorted by DEX Score.
| Melatonin | ★★★★★ | Low |
| Green Tea | ★★★★★ | Low |
| Caffeine | ★★★★★ | Low |
| Vitamin D | ★★★★★ | Low |
| Tyrosine | ★★★★★ | Low |
| Phosphatidylcholine | ★★★★★ | Low |
| Branched Chain Amino Acids (BCAAs) | ★★★★★ | Low |
| Black Tea | ★★★★★ | Low |
| Selenium | ★★★★★ | Very Low / None |
| NADH | ★★★★★ | Very Low / None |
Studies
Find individual evidence reviews for supplements sorted by DEX Score.
10 supplements for and rated at least stars. All purchase bands. No minimum star filter.
MelatoninView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if melatonin helps people with dementia think more clearly or improve behavior.
- Most research shows it does not improve memory, mood, or daily behavior in Alzheimer’s disease or other dementias.
- Some studies suggest it may help reduce evening confusion and restlessness (called sundowning) when taken in low doses at night for several weeks.
Browse 10 studies·3 meta-analyses
MetaComparative Efficacy, Tolerability, and Acceptability of Donanemab, Lecanemab, Aducanumab, Melatonin, and Aerobic Exercise for a Short Time on Cognitive Function in Mild Cognitive Impairment and Mild Alzheimer's Disease: A Systematic Review and Network Meta-Analysis2024n=4,599
A network meta-analysis of 10 RCTs (4,599 MCI/mild AD patients) found melatonin significantly more effective than donanemab, lecanemab, aducanumab, and placebo for cognitive function, with excellent tolerability.
- Effect
- Benefit
- Population
- MCI patients
- Participants
- 4,599
RCTMelatonin effects on EEG activity during non-rapid eye movement sleep in mild-to-moderate Alzheimer´s disease: a pilot study2021
In 8 mild-to-moderate Alzheimer’s patients, a crossover trial of 5 mg fast-release melatonin altered NREM EEG: increased theta power in the left-central hemisphere and reduced beta/gamma coherence in the right hemisphere during deep sleep.
- Effect
- Benefit
- Dose
- 5 mg/day
- Population
- Dementia patients
MetaNeurocognitive effects of melatonin treatment in healthy adults and individuals with Alzheimer's disease and insomnia: A systematic review and meta-analysis of randomized controlled trials2021
A meta-analysis of 22 RCTs found >12 weeks of melatonin improved MMSE scores by 1.82 points in Alzheimer's disease, with significant benefit in mild-stage AD (MD 1.89).
- Effect
- Benefit
- Population
- Healthy adults
Systematic reviewPharmacological and non-pharmacological interventions to enhance sleep in mild cognitive impairment and mild Alzheimer's disease: A systematic review2021n=10
A systematic review of 18 interventional studies in MCI/mild AD found adapted CBT-I, suvorexant, and melatonin each significantly improved sleep parameters, with melatonin reducing sleep latency in two small studies.
- Effect
- Benefit
- Population
- MCI patients
- Participants
- 10
- Avg age
- ~74
RCTDietary Melatonin Therapy Alleviates the Lamina Cribrosa Damages in Patients with Mild Cognitive Impairments: A Double-Blinded, Randomized Controlled Study2020n=40
In 40 patients with mild cognitive impairment, double-blind melatonin treatment reduced thinning of the lamina cribrosa compared with placebo, a structural ocular marker linked to neurodegeneration.
- Effect
- Benefit
- Population
- MCI patients
- Participants
- 40
MetaMeta-analysis of randomized, double-blind, placebo-controlled trials of melatonin in Alzheimer's disease2017n=462
A meta-analysis of 7 RCTs (n=462) found melatonin prolonged total sleep time in Alzheimer’s disease (SMD 0.26), though effects on cognition were inconsistent across trials.
- Effect
- Benefit
- Duration
- 10 days to 24 weeks
- Population
- Dementia patients
- Participants
- 462
RCTEffects of a diet integration with an oily emulsion of DHA-phospholipids containing melatonin and tryptophan in elderly patients suffering from mild cognitive impairment2012n=11
In 25 elderly adults with MCI, 12 weeks of DHA-phospholipid emulsion with melatonin and tryptophan did not significantly improve cognition versus placebo.
- Effect
- No Benefit
- Duration
- 12 weeks
- Population
- Older adults
- Participants
- 11
- Avg age
- ~86±6
Systematic reviewEffectiveness of melatonin treatment on circadian rhythm disturbances in dementia. Are there implications for delirium? A systematic review2010n=243
A systematic review of 9 studies (330 dementia patients) found melatonin improved sundowning/agitated behavior and suggested a role in delirium prevention through circadian stabilization.
- Effect
- Benefit
- Population
- Dementia patients
- Participants
- 243
RCTMelatonin fails to improve sleep or agitation in double-blind randomized placebo-controlled trial of institutionalized patients with Alzheimer disease2009n=24
In 24 institutionalized Alzheimer’s patients, 8.5 mg melatonin nightly for 10 days did not improve actigraphy-measured sleep or reduce agitation versus placebo.
- Effect
- No Benefit
- Duration
- 10 days
- Dose
- 8.5 mg/day
- Population
- Dementia patients
- Participants
- 24
MetaMelatonin for cognitive impairment2006n=157
A Cochrane review of melatonin for dementia/cognitive impairment (n=157) found limited evidence for cognitive benefit, though some trials reported improved sleep and circadian regulation.
- Effect
- No Benefit
- Dose
- 2.5 mg/day
- Population
- MCI patients
- Participants
- 157
CaffeineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Caffeine appears to offer some protection against dementia, with several studies suggesting it may help reduce the risk of cognitive decline later in life.
- For example, drinking 3 to 5 cups of coffee daily during midlife was linked to about a 65% lower risk of developing dementia or Alzheimer’s disease in old age.
- Another review of multiple studies found caffeine intake was associated with a modest decrease in dementia risk.
- Research focused on women also showed those with higher caffeine consumption had lower chances of developing dementia.
- However, because studies vary in how they were done and there aren’t enough large trials, more research is needed to confirm these findings.
Browse 3 studies·1 meta-analysis
RCTRelationships Between Caffeine Intake and Risk for Probable Dementia or Global Cognitive Impairment: The Women's Health Initiative Memory Study2016n=6
In 6,467 postmenopausal women followed up to 10 years, caffeine intake above the median (~261 mg/day) was associated with 26% lower hazard of probable dementia and cognitive impairment versus lower intake.
- Effect
- Benefit
- Dose
- 261 mg/day
- Population
- Postmenopausal women
- Participants
- 6
- Ages
- 65+
Caffeine as a protective factor in dementia and Alzheimer's disease2010
A narrative review concluded moderate coffee consumption (3–5 cups/day) may lower dementia and Alzheimer's risk, possibly via caffeine, antioxidants, and improved insulin sensitivity, but more prospective data are needed.
- Effect
- Benefit
Systematic reviewCaffeine intake and dementia: systematic review and meta-analysis2010
A systematic review and meta-analysis of 11 cohort/case-control studies found caffeine/coffee associated with reduced dementia risk (summary RR 0.84), though heterogeneity and methodological differences limit certainty.
- Effect
- Benefit
Green TeaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Drinking green tea daily may lower the risk of memory problems and dementia.
- Studies suggest the more green tea people drink, the lower their risk, with about a 6% reduction for each extra cup.
- Some research shows that drinking green tea at least once a week can cut dementia risk by half, especially in middle-aged and older adults.
- Drinking tea along with coffee may offer additional protection.
- Most benefits are seen in Asian populations, but more research is needed to confirm these findings widely.
Browse 4 studies·1 meta-analysis
MetaAlcohol, coffee and tea intake and the risk of cognitive deficits: a dose-response meta-analysis2021
A dose-response meta-analysis found moderate tea consumption associated with lower cognitive deficit risk, while heavy alcohol intake increased risk.
- Effect
- Benefit
- Dose
- 11 g/day
ObservationalAssociation of coffee, green tea, and caffeine with the risk of dementia in older Japanese people2021n=13
In an 8-year cohort of 13,757 middle-aged and older adults, coffee and green tea consumption were inversely associated with incident dementia risk.
- Effect
- Benefit
- Dose
- 326 mL/day
- Population
- Adults
- Participants
- 13
- Ages
- 40–74
ObservationalConsumption of coffee and tea and risk of developing stroke, dementia, and poststroke dementia: A cohort study in the UK Biobank2021n=365,682
In 365,682 UK Biobank participants followed 11.4 years, 2–3 cups/day coffee plus 2–3 cups/day tea was associated with 32% lower stroke and 28% lower dementia risk versus non-consumers.
- Effect
- Benefit
- Population
- Older adults
- Participants
- 365,682
- Ages
- 50–74
ObservationalConsumption of green tea, but not black tea or coffee, is associated with reduced risk of cognitive decline2014n=723
In a prospective study of 723 Japanese adults over 60, higher green tea consumption was associated with lower incidence of dementia and MCI over follow-up.
- Effect
- Benefit
- Duration
- 1–6 days
- Population
- Older adults
- Participants
- 723
- Ages
- 60+
Vitamin DView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if vitamin D helps people with dementia.
- Research shows that people with dementia have slightly lower levels of vitamin D in their blood compared to those without dementia.
- But it is unknown if taking vitamin D supplements makes a difference for dementia.
Browse 1 study·1 meta-analysis
MetaVitamin D, cognition, and dementia: a systematic review and meta-analysis2012
A systematic review found lower vitamin D concentrations associated with poorer cognitive performance and higher Alzheimer disease risk in observational studies, with limited RCT evidence.
- Effect
- Benefit
- Population
- Adults
Black TeaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is uncertain if black tea alone helps prevent dementia.
- A study suggests that drinking about 4 cups of tea with half to one cup of coffee daily lowers the risk of dementia by 30% compared to not drinking either.
- Drinking 2 to 3 cups of both tea and coffee daily is also linked to a lower risk of dementia-related stroke.
Browse 1 study
ObservationalConsumption of coffee and tea and risk of developing stroke, dementia, and poststroke dementia: A cohort study in the UK Biobank2021n=365,682
In 365,682 UK Biobank participants followed 11.4 years, 2–3 cups/day coffee plus 2–3 cups/day tea was associated with 32% lower stroke and 28% lower dementia risk versus non-consumers.
- Effect
- Benefit
- Population
- Older adults
- Participants
- 365,682
- Ages
- 50–74
Branched Chain Amino Acids (BCAAs)View supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Research shows that people with higher levels of branched-chain amino acids (BCAAs) in their blood may have a 13% to 17% lower risk of developing dementia.
- More research is needed to understand how BCAAs might help prevent memory loss and dementia.
Browse 1 study
ObservationalAssociation of branched-chain amino acids and other circulating metabolites with risk of incident dementia and Alzheimer's disease: A prospective study in eight cohorts2018n=22,623
A prospective analysis of 22,623 participants across 8 cohorts found higher circulating BCAAs, creatinine, and certain lipoproteins were associated with lower dementia and Alzheimer's disease risk.
- Effect
- Benefit
- Participants
- 22,623
PhosphatidylcholineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It’s unclear whether taking phosphatidylcholine helps with dementia.
- One long-term study found men who consumed more phosphatidylcholine daily had a lower risk of developing dementia, but this does not prove it prevents the disease.
- More research is needed.
Browse 1 study
Clinical trialAssociations of dietary choline intake with risk of incident dementia and with cognitive performance: the Kuopio Ischaemic Heart Disease Risk Factor Study2019n=1,259
In 1259 Finnish men followed 21.9 years, highest versus lowest phosphatidylcholine intake quartile had 28% lower dementia risk (P-trend=0.02).
- Effect
- Benefit
- Dose
- 88 mg/day
- Population
- Men
- Participants
- 1,259
- Ages
- 42–60
TyrosineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- There is no clear evidence that tyrosine alone helps dementia.
- A small study gave people with severe Alzheimer’s or multi-infarct dementia a combination of tyrosine and other supplements but saw no improvement in symptoms.
- The study was very small and did not have a comparison group.
Browse 1 study
Neurotransmitter precursor amino acids in the treatment of multi-infarct dementia and Alzheimer's disease1977n=10
A study of 10 dementia patients found that tyrosine (4 g/day) plus 5-HTP (800 mg/day) improved clinical and psychologic outcomes in 2 of 10 patients with multi-infarct or mixed dementia.
- Effect
- Benefit
- Dose
- 800 mg/day
- Population
- Patients with Alzheimer's disease
- Participants
- 10
SeleniumView supplement →
Do not purchase·★★★★★
How we scored this▸
- Selenium has insufficient evidence for Dementia.
Browse 1 study
RCTAssociation of Antioxidant Supplement Use and Dementia in the Prevention of Alzheimer's Disease by Vitamin E and Selenium Trial (PREADViSE)2017n=7,540
In 3786 older men from PREADViSE/SELECT, vitamin E or selenium used up to 7 years did not prevent dementia versus placebo.
- Effect
- No Benefit
- Population
- Older men
- Participants
- 7,540
- Ages
- 60+
NADHView supplement →
Do not purchase·★★★★★
How we scored this▸
- Taking oral NADH does not improve memory, cognitive performance, or behavioural function compared to baseline in patients with mild to moderate Alzheimer's disease.
Browse 1 study
Open-labelNo evidence for cognitive improvement from oral nicotinamide adenine dinucleotide (NADH) in dementia2000n=25
A 3-month open-label study in 25 dementia patients on cholinomimetic drugs found 10 mg/day NADH produced no measurable cognitive benefit on standard psychometric tests.
- Effect
- No Benefit
- Dose
- 10 mg/day
- Population
- Dementia patients
- Participants
- 25
Evidence visualised
Same ratings as above, aggregated so you can see coverage and imbalance.
| Supplement | DEX | Studies | Meta-analyses | Share |
|---|---|---|---|---|
| Melatonin | ★★★★★56% | 10 | 3 | 42% |
| Green Tea | ★★★★★52% | 4 | 1 | 17% |
| Caffeine | ★★★★★52% | 3 | 1 | 13% |
| Black Tea | ★★★★★40% | 1 | 0 | 4% |
| Branched Chain Amino Acids (BCAAs) | ★★★★★40% | 1 | 0 | 4% |
| NADH | ★★★★★24% | 1 | 0 | 4% |
| Phosphatidylcholine | ★★★★★40% | 1 | 0 | 4% |
| Selenium | ★★★★★32% | 1 | 0 | 4% |
| Tyrosine | ★★★★★40% | 1 | 0 | 4% |
| Vitamin D | ★★★★★48% | 1 | 1 | 4% |