Each study has a usefulness score out of 100 (rubric version 4.0). Tap a score to see what makes it up.
Highest usefulness score first. Studies without a score come last.
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Selection criteria All unconfounded, double-blind, randomized controlled trials in which treatment with donepezil was compared with placebo for patients with mild, moderate or severe dementia due to Alzheimer's disease.
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Dementia is a leading cause of death and disability worldwide.
Why it matters
In this cluster-randomized trial of 33,995 people in rural China with uncontrolled hypertension, an intensive blood pressure reduction programme significantly lowered the risk of all-cause dementia compared with usual care. It indicates that intensive blood pressure control can reduce dementia risk in people with hypertension, but it does not address treating or curing dementia once it has developed.
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The incidence rate of dementia in Europe and North America has declined by 13% per decade over the past 25 years, consistently across studies.
Why it matters
Pooling 7 population cohorts from Europe and the United States (49,202 people over 65, followed between 1988 and 2015), this study found the rate of new all-cause dementia cases fell by 13% per decade (95% CI 7–19%), consistently across the cohorts. The fall was larger in men (24%) than in women (8%, CI 0–15%). The authors say the causes of the decline are unknown and that the results still need to be checked in more geographically and ethnically diverse populations. This is a trend in how often new cases arise, not a test of any treatment.
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Among sedentary older adults, a 24-month moderate-intensity physical activity program compared with a health education program did not result in improvements in global or domain-specific cognitive function.
Why it matters
In this randomized trial, a 24-month moderate-intensity physical activity program did not improve global or domain-specific cognitive function compared with a health education program in sedentary older adults. Some subgroups aged 80 or older and those with poorer baseline physical performance showed better executive function changes, but the main result was no overall benefit.
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Epidemiologic studies suggest that a Mediterranean diet, an antioxidant-rich cardioprotective dietary pattern, delays cognitive decline, but clinical trial evidence is lacking.
Why it matters
In this randomized trial of an older population, 334 participants had follow-up cognitive tests after a median of 4.1 years. The group assigned to a Mediterranean diet plus olive oil scored better than the control-diet group on two tests (RAVLT, P = .049; Color Trail Test part 2, P = .04), with no differences on the other tests. The study measured test scores, not dementia, so it does not show that this diet prevents or treats Alzheimer's disease.
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Evidence suggests that delirium is associated with long-term poor outcome but delirium often occurs in individuals with more severe underlying disease.
Why it matters
Pooling studies of older patients, this 2010 meta-analysis found that people who had delirium were more likely to have died about two years later (hazard ratio 1.95), to have moved into an institution (odds ratio 2.41), and to have developed dementia over about four years, and that these links held "independent of important confounders, such as age, sex, comorbid illness or illness severity, and baseline dementia." The dementia estimate comes from only 2 studies and is very imprecise (odds ratio 12.52, 95% CI 1.86–84.21), so it shows a direction of risk rather than a reliable size. This is an association: the study did not test whether preventing or treating delirium changes any of these outcomes.
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In this study, G. biloba at 120 mg twice a day was not effective in reducing either the overall incidence rate of dementia or AD incidence in elderly individuals with normal cognition or those with MCI.
Why it matters
In this trial of 3069 community volunteers aged 75 or older, Ginkgo biloba did not reduce the incidence of all-cause dementia or Alzheimer disease compared with placebo. The dementia rate was 3.3 per 100 person-years in the Ginkgo biloba group and 2.9 per 100 person-years in the placebo group.
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Atypical antipsychotic drugs may be associated with a small increased risk for death compared with placebo.
Why it matters
This meta-analysis of randomized placebo-controlled trials found that atypical antipsychotic drugs, used for delusions, aggression, and agitation in people with dementia, may be associated with a small increased risk of death compared with placebo. It does not address treating, curing, or preventing Alzheimer's disease itself.
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Among postmenopausal women aged 65 years or older, estrogen plus progestin did not improve cognitive function when compared with placebo.
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81/100
Pooling data on more than 600,000 people, this meta-analysis found that people who reported feeling lonely had about a 30% higher risk of developing dementia overall, and even higher risk for vascular dementia specifically, even after accounting for depression and objective social isolation.
Why it matters
People who reported feeling lonely had about 31% higher risk of all-cause dementia, with higher risk for Alzheimer's disease and vascular dementia specifically, even after accounting for depression and social isolation. This identifies loneliness as a risk factor, but the pooled observational data cannot show that reducing loneliness prevents dementia.
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The 172 total participants had a mean (SD) age of 75.7 (4.8) years, and 108 (62.8%) were women.
Why it matters
In this trial of 172 older adults at elevated dementia risk, those assigned to personalized risk-reduction strategies showed larger improvements in a composite cognitive score and a better composite risk factor score after two years than the control group. This suggests multidomain risk-reduction may help cognition in people with risk factors, but it does not show that Alzheimer's disease is cured or prevented.
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The intervention did not improve global cognitive performance.
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Further studies are warranted to develop and refine the specific MIND diet for different populations.
Why it matters
This analysis of three cohort studies plus a meta-analysis found that higher MIND diet scores were linked to lower dementia risk. Because it is observational, it shows an association and cannot prove that the diet prevents dementia.
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Only RCTs were included in this study; there were eleven studies ( n = 2609 participants) of the Mediterranean diet, seven studies ( n = 313) of the ketogenic diet and one study ( n = 37) of the MIND diet.
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This systematic review suggests that CCT interventions could improve global cognitive function in patients with MCI.
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Vascular management takes place every 3-6 months or otherwise as specified by study physicians.
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There is moderate-certainty evidence regarding the benefit of multicomponent non-pharmacological interventions for the prevention of delirium in hospitalised adults, estimated to reduce incidence by 43% compared to usual care.
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Providing multidomain lifestyle training through a web-platform is feasible and well-accepted, but the training should be challenging enough and adequately progress according to participants' capabilities to increase adherence.
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Both increased sympathetic activity and decreased parasympathetic activity seem to be associated with a worse performance in the cognitive domains considered, in the absence of dementia and severe cardiovascular diseases or other medical and psychiatric diseases.
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In a large placebo-controlled randomized trial, we found that pantoprazole is not associated with any adverse event when used for 3 years, with the possible exception of an increased risk of enteric infections.
Why it matters
In this large randomized trial, pantoprazole use was not linked to a significant difference in dementia or most other safety outcomes compared with placebo, except for a small increase in enteric infections. This means long-term use of this drug was not found to raise or lower dementia risk in this trial.
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The results of this meta-analysis demonstrate that cognitive impairment and delirium are major issues in CABG patients which require specific attention.
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In analyses that addressed bias due to reverse causation, physical inactivity was not associated with all-cause dementia or Alzheimer's disease, although an indication of excess dementia risk was observed in a subgroup of physically inactive individuals who developed cardiometabolic disease.
Why it matters
In this analysis of 404,840 people, physical inactivity was not associated with all-cause dementia or Alzheimer's disease once bias from reverse causation was addressed. This is a null result and does not support physical inactivity as a cause of dementia.
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After a median of 4.7 years of follow-up, the rate of cardiovascular disease was 10.7 events per 1000 person-years in the aspirin group and 11.3 events per 1000 person-years in the placebo group (hazard ratio, 0.95; 95% confidence interval [CI], 0.83 to 1.08).
Why it matters
In 19,114 healthy adults aged 70+ (65+ for Black and Hispanic participants in the US), daily 100 mg aspirin did not clearly lower heart attacks, strokes or heart failure over a median 4.7 years (10.7 vs 11.3 events per 1000 person-years; hazard ratio 0.95, 95% CI 0.83 to 1.08). It did raise major bleeding (8.6 vs 6.2 per 1000 person-years; hazard ratio 1.38). The trial's dementia result is reported in a separate paper, so this study offers no evidence that aspirin prevents Alzheimer's.
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The mean age of the 402 study residents was 86.7 years [range, 67-102 years]; 350 were white (87.1%) and 323 were female (80.3%), with DNH directives that by 6 months did not differ between arms (63% in both arms; adjusted odds ratio [AOR], 1.08; 95% CI, 0.69-1.69).
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Current pharmacologic therapies are for symptomatic AD patients, whereas nonpharmacologic training is administrable before symptom onset.