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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This study sought to replicate and build upon a previously published case series report describing improved cognitive function in five patients with mild-to-moderate dementia after 12 weeks of transcranial and intranasal near-infrared (NIR) PBM therapy.
Why it matters
This pilot trial randomized only eight people with dementia to 12 weeks of home photobiomodulation treatments or usual care. The very small sample makes this preliminary, and it does not establish whether photobiomodulation treats or prevents dementia.
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62/100
Although the association between high blood pressure (BP), particularly in midlife, and late-life dementia is known, less is known about variations by race and sex.
Why it matters
This cohort study found that higher systolic blood pressure, lower diastolic blood pressure and higher pulse pressure were associated with faster cognitive decline with increasing age. It identifies associations between blood pressure and cognition and does not test any treatment, cure or prevention.
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Qualitatively, our review of 57 MCI versus HC comparisons suggests substantial inconsistency; 9 showed no group difference, 8 showed MCI > HC and 22 showed HC > MCI across the brain, and 18 showed regionally-mixed directions of effect.
Why it matters
This systematic review and meta-analysis examined default mode network connectivity in mild cognitive impairment across many studies. It found the pattern of altered connectivity was complex and inconsistent, and concluded that no index of default mode network connectivity currently qualifies as a useful biomarker.
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High adherence to the MIND diet was associated with a slower rate of cognitive decline after stroke.
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Five hundred and forty five patients from 67 NH units were included and randomized to the intervention ( N = 297; 36 units) and control group ( N = 248; 31 units).
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Future well-designed longitudinal researches examining the direct and indirect relationship between tooth loss and dementia risk are encouraged.
Why it matters
This meta-analysis of observational studies found that people with multiple tooth loss had a higher incidence of dementia, and the association remained when adjusted results were pooled. As a review of observational studies, it shows an association and cannot establish that tooth loss causes dementia.
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We analyzed data from 11,709 participants without a history of coronary heart disease or stroke who attended the baseline examination (1987-1989) of the prospective Atherosclerosis Risk in Communities (ARIC) study.
Why it matters
This study found that orthostatic hypotension was associated with incident dementia, stroke, and long-term cognitive decline in a large cohort. It does not show that treating orthostatic hypotension prevents dementia, and the results are observational.
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62/100
Discussing future care is difficult due to uncertainties about the future and the decisional capacities of people with dementia.
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Non-motor symptoms (NMS) of Parkinson's disease can be predominant as the disease advances, thereby constituting a major source of disease burden for patients and caregivers.
Why it matters
This review concerns non-motor symptoms of Parkinson's disease, including cognitive impairment and dementia, and identifies risk factors for these symptoms. It states that only antiparkinsonian medication is potentially modifiable and that disease-modifying therapies have not yet been developed, so it offers no treatment, cure, or prevention for Alzheimer's disease.
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According to study results, a higher adherence to the Mediterranean diet was associated with lower odds of frailty, irrespective of the definition used.
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Both interventions were highly feasible and acceptable and allowed improvement in different aspects of cognitive and psychosocial functioning in MCI subjects.
Why it matters
In this small randomized study of 19 patients with mild cognitive impairment, those in the computerized cognitive stimulation group improved on part B of the Trail Making Test and self-esteem, while the computerized cognitive engagement group improved on part A of the Trail Making Test. The sample is very small, so it is too early to say whether these programs prevent dementia.
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Level of evidence Level V, systematic review.
Why it matters
All 17 studies in this review found that hearing loss is associated with dementia or cognitive decline. The methods used to measure hearing loss and dementia varied widely across studies, and the review does not show that treating hearing loss prevents dementia.
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Previous neuroimaging studies reveal that MCI is associated with aberrant sensory-perceptual processing in cortical brain regions subserving auditory and language function.
Why it matters
In older hearing-matched listeners, mild cognitive impairment was associated with larger brainstem and cortical speech-evoked responses despite no perceptual speech deficits, and dual brainstem-cortical speech activity identified MCI listeners with 80% accuracy. The findings suggest a possible biomarker of early cognitive decline and concern detection, not treating, curing, or preventing Alzheimer's disease.
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62/100
We thus examined whether higher blood cholesterol concentrations were associated with faster cognitive decline in a community-based longitudinal study of Chinese elderly.
Why it matters
This study followed 1,159 older Chinese adults to see whether higher blood cholesterol was linked to faster cognitive decline. It does not test any treatment, cure, or prevention for Alzheimer's disease.
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Cognitively normal elderly individuals who engage in specific mentally stimulating activities even in late life have a decreased risk of incident MCI.
Why it matters
In this cohort of cognitively normal older adults, playing games, doing crafts, using a computer, and social activities were each associated with a lower risk of developing mild cognitive impairment. The study followed participants for a median of 4 years and did not test whether these activities prevent Alzheimer's disease itself.
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We observed 234 cases of all-cause dementia over 10 years of follow-up.
Why it matters
This study found that prolonged self-reported sleep duration was associated with an increased risk of incident dementia over 10 years. It is observational, so it cannot show that changing sleep duration prevents dementia.
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Age-related cognitive impairment and dementia are an increasing societal burden.
Why it matters
This trial tested combined physical and cognitive training in 113 people with mild cognitive impairment. It does not report that this training cures or prevents Alzheimer's disease.
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A growing body of evidence suggests that adherence to the Mediterranean diet (MD) may protect against cognitive decline and dementia.
Why it matters
This systematic review found that in most studies, adherence to the Mediterranean diet was associated with better cognitive performance and a decreased risk of cognitive impairment, dementia, or Alzheimer's disease, though some studies found no association. The authors note limitations in study design and do not claim the diet prevents dementia.
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Recent demographic trends indicate that older people appear to be one of the fastest growing population groups worldwide.
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Microbleed prevalence was 15.3% (median [interquartile range] count, 1 [1-88]).
Why it matters
In this population study, having more than four cerebral microbleeds was examined for links to cognitive decline and dementia. It looks at a possible marker of brain damage rather than a treatment or cure.
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The objective of this study was to derive food-based dietary guidelines for the Dutch population.
Why it matters
This guideline review found strong evidence linking diet to dementia risk, among other chronic diseases, and used it to formulate food-based dietary guidelines. It offers dietary guidance that may help lower dementia risk, but it does not test a treatment or cure for Alzheimer's disease.
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Dietary patterns characterized by the aMED, HEI-2010, AHEI-2010, or DASH dietary score were not associated with cognitive decline in older women.
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There are cross-sectional evidences of an association between sleep disorders and cognitive impairment on older adults.
Why it matters
This meta-analysis found that insomnia was associated with an increased risk of all-cause dementia, though the studies were highly inconsistent. It suggests screening and managing insomnia might be worth studying for prevention, but does not show that treating insomnia prevents dementia.
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Dementia rates varied over 60% between groups, providing a comprehensive benchmark for the NAPA goal of reducing disparities.
Why it matters
In 274,283 health-plan members aged 64 and over followed from 2000 to 2013, dementia incidence ranged from 26.6 per 1,000 person-years in African-Americans and 22.2 in American Indian/Alaska Native members down to 15.2 in Asian-Americans. That is a 65% higher risk for African-Americans than Asian-Americans (hazard ratio 1.65, 95% CI 1.58–1.72) after adjusting for age, sex, medical use and other illnesses. The authors present these rates as a benchmark for the national goal of reducing disparities. This is an observational study: it shows that rates differ, not why, and it does not test any way of lowering them.
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This search located 10,338 individual references, of which 164 are included in this review.
Why it matters
This rapid systematic review of cohort studies found consistent evidence of beneficial associations between physical activity in mid-life and healthy ageing and disease outcomes, including dementia. It reviews observational evidence only and does not show that changing behaviour in mid-life prevents dementia.
From across this topic
10 of the 7,967 studies in this topic, picked by a fixed rule (a hash of each study's address), not by score or date; each page of this list shows a different 10. The same 10 appear here every time.
- Mediterranean diet and dementia: MRI marker evidence from meta-analysis
- Caregiving Across Diverse Populations: New Evidence From the National Study of Caregiving and Hispanic EPESE
- Targeting brain health in subjective cognitive decline: insights from a multidomain randomized controlled trial
- Silent Brain Infarcts and the Risk of Dementia and Cognitive Decline
- A single-question screen for rapid eye movement sleep behavior disorder: a multicenter validation study
- Language, literacy, and sensory impairments and missing cognitive test scores in the Harmonized Cognitive Assessment Protocol of the China Health and Retirement Longitudinal Study
- Confounder adjustment in observational studies investigating multiple risk factors: a methodological study
- Disability and decline in physical function associated with hospital use at end of life
- Cognitive decline in Parkinson disease
- Predicting Subjective Cognitive Decline on Future BRFSS Survey Years: An Open Multi-Language Machine Learning Benchmark