For how we live.
In a 12-month trial of 89 older adults with vascular cognitive impairment, strength training did not slow whole-brain white-matter lesions overall — but it did in women, and in two specific brain regions.
A Korean cohort of 1.37 million women found more dementia after hypertensive pregnancies. The association did not survive adjustment for the vascular and metabolic conditions that followed.
In LatAm-FINGERS, 1,065 at-risk older adults across 11 countries did better on cognitive tests with structured coaching than with flexible health advice over two years. The gap was small.
Retrospective studies keep finding bilinguals develop dementia symptoms three to four years later than monolinguals. Prospective studies that follow healthy people find no drop in who gets it at all.
US POINTER randomised 2,111 at-risk older adults to two lifestyle programmes. The structured version beat the self-guided one on cognition — but by a modest margin, and there was no do-nothing group to compare against.
Observational studies tie hearing loss to faster mental decline. But the first large randomised trial found no overall benefit from hearing aids over three years — with a signal of help only in higher-risk older adults.
A landmark trial pushed blood pressure hard and cut mild cognitive impairment — but its headline dementia result fell short of significance after the study stopped early. The pooled trial evidence is real, and modest.
Physically acting out dreams is one of the strongest known early signs of Parkinson's and related diseases. In a 1,280-patient cohort, most converted within 12 years — but it is a risk marker, not a verdict.
The idea that sleep flushes toxins from the brain rests largely on mouse experiments. A 2024 study using the same animal measured the opposite direction, and none of it has been shown in humans.
Everyday lapses are a poor guide to trouble. The line that matters is whether memory loss is measurable beyond your age and whether it is starting to affect daily function.
Autophagy is the cell's self-clearing recycling process, and it wanes with age. Fasting, spermidine and rapamycin switch it on in lab animals — whether that extends human life is unproven.
A matched cohort of 173,910 people with dementia in England tied the drugs to raised risks of pneumonia, stroke, clots, heart attack, fracture and kidney injury — highest just after starting.
Eligibility set by exact date of birth created a natural experiment. Vaccinated people had a 20% lower relative risk of dementia over seven years. It is one striking study, and it tested the older live vaccine.
Forgetting a name is not dementia, and a third of people diagnosed with mild cognitive impairment revert to normal. But that diagnosis still carries weight: risk of dementia stays elevated even in those who bounce back.
Dietary spermidine tracks with markedly lower mortality in one population study. The first year-long randomised trial of a spermidine supplement found no effect on memory.
Cataract surgery was tied to 29% lower dementia risk in a strong cohort. But the largest hearing-aid trial found no overall effect on cognition. The signal is real; the proof that fixing senses prevents dementia is not.
Structured counselling for a spouse delayed a patient's nursing-home admission by an estimated 557 days. Other trials cut carer depression sharply, though the effect on institutionalisation is less consistent.
A landmark trial cut delirium from 15.0% to 9.9% by addressing six ordinary risk factors together. Drugs, including antipsychotics, have not shown the same clear preventive benefit.
In 33 former players with autopsy-confirmed disease, memory, executive-function and language impairments were frequent before death, and greater tau burden tracked worse memory.
STAREE randomised 9,971 Australians aged 70 and over to atorvastatin or placebo. Cardiovascular events fell by 30%. Death, dementia and persistent disability, taken together, did not move.
A systematic review of longitudinal MRI after CPAP for sleep apnoea finds changes reported in every domain and reproducible effects in none — a useful map of what the evidence does not yet show.
The range is the finding, not a failure of the study. 1,712 former players died between 2008 and 2021; 338 brains were examined, and who donates a brain is not random.
Two large cohorts link purpose in life to lower mortality and lower Alzheimer's risk. Whether purpose protects health, or health sustains purpose, is what the studies cannot fully separate.
Three successive birth cohorts over 22 years show falling prenatal pollution and rising test scores together. A separate review explains why the pathway from one to the other is still poorly mapped.
A 614-donor autopsy study tied advanced CTE to dementia independently of other brain disease. A separate imaging report in three former athletes hints at a test for the living. The caveats on both are heavy.
Stanford's SleepFM, published in Nature Medicine in January 2026, is the most consequential sleep paper of the year. Its own limitations section explains why it is not yet a clinical test.
The approved tests are for patients already showing cognitive decline. Used on the worried well, a positive result mostly signals a risk that may never become disease — and no treatment follows from it.
A review pooling prevalence across the region ties the projection to modifiable risks that are unusually common there — smoking, inactivity, diabetes — layered on rapid ageing.
Autopsy studies show educated brains carry the same disease but express it as dementia later. That is the concept's strength — and the reason it resists being turned into a to-do list.
ACHIEVE randomised 977 older adults and measured three-year cognitive change. The difference between hearing aids and health education was 0.002 SD units, p=0.96. One subgroup result is doing a lot of work.
Observational studies tie fitness to slower cognitive decline. When researchers randomise older adults to exercise, the cognitive payoff shrinks — in a Cochrane review of healthy people, to nothing.
The link between puzzles and a sharper old age is real in the data and largely the wrong way round: the earliest changes of dementia quietly reduce the very activities that later look protective.
A diet built to protect the brain looked powerful when researchers watched who chose to eat it. When they assigned it in a three-year trial, both groups improved by almost exactly the same amount.
A consortium reduced overnight sleep studies to nine composites. Two tracked with better cognition. None tracked with whether a person later developed dementia.
The best long-term trial found trained skills can last a decade. Whether they transfer to daily life, or hold off dementia, is where the evidence — and the FTC — parted ways with the marketing.
A standing commission estimates that eliminating 14 risk factors could prevent or delay 45% of dementia across a whole population. What that number means for one person is a different and much weaker claim.
A 2025 meta-analysis of 57 studies found the mortality curve bending at about 7,000 steps a day. The 10,000 figure traces to the trade name of a Japanese step counter sold in 1965.
Imaging finds smaller brain volumes from as little as one to two daily drinks. Long-run dementia studies show a U-shape, with abstainers also at higher risk — a pattern that is easy to misread.
A burden-of-disease calculation built on EU noise-mapping data puts numbers on two outcomes that noise research has mostly ignored. The confidence intervals are as informative as the estimates.
A six-year cohort study using Japan's long-term care records found a roughly 25% lower risk. The design cannot separate cooking from the ability to cook.
Pooling 94 cohort studies, grip strength tracked with later dementia, depression and disability. The authors rate their own confidence in the numbers as limited to moderate.
A 131,821-person cohort followed for up to 43 years and a dose-response meta-analysis of 450,000 people converge on roughly two to three cups — and diverge sharply above it.
A mirror that scores physiological age in 30 seconds. A watch that watches your gait for dementia. The gap between what these products measure and what they imply is the story of the show.
Pooling ten studies, researchers found menopause hormone therapy neither raised nor lowered dementia risk. The certainty of that evidence ranged from moderate to very low.
The guidance is built on one negative instruction: do not stop abruptly in patients likely to be physically dependent. Hong Kong records show the sharpest prescribing rise in 18-to-25-year-olds.